ci: fix tauri --ci flag in woodpecker

- vitest actually runs 373 cases across 21 files, not 259
- added workspace.ts, sparkline.ts, logger.ts to the file tree in ARCHITECTURE
- fixes in all four language variants: README + ARCHITECTURE in EN and RU

.github/workflows/release.yml

@@ -14,18 +14,40 @@ jobs:
       fail-fast: false
       # tauri-action's find-or-create-release check races across parallel
       # matrix jobs and can create two separate release objects for the
-      # same tag, each missing the other's assets — force serial builds
+      # same tag, each missing the other's assets — force serial builds.
+      # Every platform added below shares that release object, so they all
+      # have to stay in this one serialized matrix.
       max-parallel: 1
       matrix:
         include:
-          - target: x86_64-pc-windows-msvc
+          - os: windows-latest
+            target: x86_64-pc-windows-msvc
             arch: x64
-          - target: aarch64-pc-windows-msvc
+          - os: windows-latest
+            target: aarch64-pc-windows-msvc
             arch: arm64
-    runs-on: windows-latest
+          # 22.04 is the oldest runner with webkit2gtk-4.1 (what Tauri 2
+          # needs); building on it keeps the glibc floor as low as possible
+          - os: ubuntu-22.04
+            target: x86_64-unknown-linux-gnu
+            arch: x64
+          - os: macos-latest
+            target: aarch64-apple-darwin
+            arch: arm64
+          - os: macos-latest
+            target: x86_64-apple-darwin
+            arch: x64
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
 
+      - if: runner.os == 'Linux'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y build-essential curl wget file \
+            libwebkit2gtk-4.1-dev librsvg2-dev libssl-dev libxdo-dev \
+            libayatana-appindicator3-dev patchelf
+
       - uses: actions/setup-node@v4
         with:
           node-version: 22
@@ -42,9 +64,19 @@ jobs:
 
       - run: npm ci
 
+      # TAURI_SIGNING_* below is the updater's minisign keypair, not OS code
+      # signing — there is no Apple certificate, so macOS builds are only
+      # ad-hoc signed (bundle.macOS.signingIdentity "-") and Gatekeeper still
+      # asks the user to allow them on first launch.
+      #
+      # RELEASE_TOKEN (fine-grained PAT, Contents: read/write) stands in for
+      # the built-in GITHUB_TOKEN: the Actions-native token started getting
+      # "Resource not accessible by integration" on release creation for this
+      # repo — confirmed not a permissions:/repo-settings/tag-protection issue,
+      # a personal token hits the same Releases API fine.
       - uses: tauri-apps/tauri-action@v0
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN }}
           TAURI_SIGNING_PRIVATE_KEY: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY }}
           TAURI_SIGNING_PRIVATE_KEY_PASSWORD: ${{ secrets.TAURI_SIGNING_PRIVATE_KEY_PASSWORD }}
         with:
@@ -63,17 +95,27 @@ jobs:
           fetch-depth: 0
 
       - env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.RELEASE_TOKEN }}
         run: |
           prev=$(git tag --sort=-v:refname | grep -v "^${{ github.ref_name }}$" | head -1)
+          # release-checklist version bumps (bump version to X / bump cargo
+          # version to X / update tauri.conf version to X / sync Cargo.lock
+          # or package-lock.json with X) are internal bookkeeping, not
+          # user-facing changes — never worth a changelog line.
+          noise='^- (bump( cargo)? version to|update tauri\.conf version to|sync (Cargo\.lock|package-lock\.json) with) [0-9]+\.[0-9]+\.[0-9]+$'
+          filter() {
+            grep -vE "$noise" \
+              | sed -E 's/ \(#[0-9]+\)$//' \
+              | perl -CSD -pe 's/^- \p{Emoji_Presentation}\x{FE0F}?\s*/- /'
+          }
           {
             echo "## What's new"
             if [ -n "$prev" ]; then
-              git log "$prev..${{ github.ref_name }}" --pretty=format:"- %s" --no-merges | grep -v "^- bump version"
+              git log "$prev..${{ github.ref_name }}" --pretty=format:"- %s" --no-merges | filter
               echo ""
               echo "**Full Changelog**: https://github.com/${{ github.repository }}/compare/$prev...${{ github.ref_name }}"
             else
-              git log "${{ github.ref_name }}" --pretty=format:"- %s" --no-merges | grep -v "^- bump version"
+              git log "${{ github.ref_name }}" --pretty=format:"- %s" --no-merges | filter
             fi
           } > notes.md
-          gh release edit "${{ github.ref_name }}" --notes-file notes.md
+          gh release edit "${{ github.ref_name }}" --notes-file notes.md --draft=false

.gitignore

@@ -2,6 +2,7 @@ node_modules/
 dist/
 src-tauri/target/
 src-tauri/gen/
+src-tauri/.cargo/
 *.log
 
 # local reference copies of third-party sources — not ours to ship
@@ -10,6 +11,10 @@ numi-master/
 
 # one-off debugging artifacts
 scripts/smoke-*
+test_perf.ts
+
+# AI coding agent scratch/notes directories
+.jules/
 
 # updater signing key — private, never publish (see .tauri-signing/README.txt)
 .tauri-signing/

.woodpecker.yaml

@@ -0,0 +1,22 @@
+when:
+  - event: [push, manual]
+
+steps:
+  - name: test-engine
+    image: node:22-bookworm-slim
+    commands:
+      - npm ci
+      - npx tsc --noEmit
+      - npx vitest run
+
+  - name: build-tauri-linux
+    image: rust:1-bookworm
+    commands:
+      - rustup component add clippy
+      - apt-get update && apt-get install -y libwebkit2gtk-4.1-dev librsvg2-dev libssl-dev libxdo-dev libayatana-appindicator3-dev
+      - curl -fsSL https://deb.nodesource.com/setup_22.x | bash -
+      - apt-get install -y nodejs
+      - npm ci
+      - cargo clippy --manifest-path src-tauri/Cargo.toml -- -D warnings
+      - cargo test --manifest-path src-tauri/Cargo.toml
+      - CI=true npx tauri build --no-bundle --ci

ARCHITECTURE.md

@@ -23,12 +23,16 @@ src/
     editor.ts        CodeMirror 6 wiring: highlight, results overlay, copy
     search.ts        cross-sheet search overlay (text + result-value queries)
     export.ts        renders the sheet + results to a PNG (clipboard/file)
+    sparkline.ts     SVG sparkline renderer for `chart` results
     app.css          themes (light/dark via CSS variables)
   main.ts            app bootstrap: documents, settings, status bar, dnd
+  workspace.ts       cross-sheet references: exports cache, cycle detection
   storage.ts         Tauri commands / localStorage fallback
-  extensions.ts      runs user .js files against the engine
+  extensions.ts      runs user .js files in a QuickJS/WASM sandbox, bridged
+                     to the engine's numi.* API
   i18n.ts            interface strings (en/ru)
   updater.ts         checks tauri-plugin-updater, installs + relaunches
+  logger.ts          thin console wrapper (info/warn/error)
 src-tauri/
   src/main.rs        tray, hide-to-tray, storage commands, rates fetching
                      (open.er-api.com + CoinGecko + Yahoo Finance v8 chart)
@@ -214,6 +218,40 @@ recursing forever.
   deleted sheets become `.numi` files under `backups/deleted/` and are pruned
   by age. Saving is debounced at 400 ms.
 
+## Platforms and packaging
+
+- One codebase, three desktop targets. `tauri.conf.json` holds everything
+  shared; the per-platform bits live in `tauri.windows.conf.json`,
+  `tauri.linux.conf.json` and `tauri.macos.conf.json`, which Tauri merges over
+  the base config (JSON Merge Patch) according to the target being built. Each
+  one only sets `bundle.targets` and that platform's bundler options — NSIS on
+  Windows, deb/rpm/AppImage on Linux, .app/.dmg on macOS.
+- `release.yml` builds five artifacts on three runner families: Windows x64 and
+  arm64, Linux x64 (`ubuntu-22.04` — the oldest runner carrying webkit2gtk-4.1,
+  which keeps the glibc floor low), macOS arm64 and x64. Two separate macOS
+  targets rather than `universal-apple-darwin`: it matches how Windows already
+  ships per-architecture, halves each download, and gives the updater the
+  `darwin-aarch64`/`darwin-x86_64` keys it looks up by default.
+- The whole matrix stays `max-parallel: 1`. Every job hands its assets to the
+  *same* GitHub Release object, and tauri-action's find-or-create check races if
+  two jobs reach it at once — adding platforms did not change that constraint,
+  it made it apply to more jobs.
+- No OS code signing anywhere. Windows ships unsigned; macOS is *ad-hoc* signed
+  (`bundle.macOS.signingIdentity: "-"`), which needs no Apple certificate but is
+  required for Apple Silicon to run a downloaded binary at all — without it the
+  arm64 build is rejected as damaged rather than merely warned about. Gatekeeper
+  still asks the user to allow the app on first launch either way.
+- `bundle.fileAssociations` covers `.numi`/`.sum` on Windows (NSIS registry
+  entries) and macOS (`CFBundleDocumentTypes`). On Linux it writes nothing
+  useful: registering an extension there also needs a shared-mime-info XML that
+  Tauri does not generate, so `.numi` files are opened by dragging them into the
+  window rather than from the file manager.
+- `icons/icon.icns` is emitted by `scripts/gen-icon.ts` alongside the PNGs and
+  the `.ico`, hand-rolled the same dependency-free way: `icns` magic + total
+  length, then one `[OSType][length][PNG]` chunk per size, using the modern
+  PNG-payload tags `iconutil` produces (`icp4`/`icp5`, `ic07`–`ic14`). Rerun it
+  with `npm run icons` after touching the artwork.
+
 ## Auto-update
 
 - `updater.ts` calls `tauri-plugin-updater`'s `check()` on boot; if a signed
@@ -241,7 +279,9 @@ recursing forever.
   flipping it while the app is running takes effect immediately); the manual
   button ignores the toggle and always works.
 - The update endpoint is `latest.json` published alongside each GitHub
-  Release. `release.yml` signs both architectures with a minisign keypair:
+  Release. `release.yml` signs every platform's updater artifact with a
+  minisign keypair (this is Tauri's own update signing, unrelated to OS code
+  signing):
   the public half is embedded in `tauri.conf.json`; the private half + its
   password live only as `TAURI_SIGNING_PRIVATE_KEY(_PASSWORD)` repo secrets
   (write-only — there is no durable copy in the repo). Losing that key means
@@ -263,7 +303,7 @@ All files below live in `%APPDATA%/app.summarum.calc` (or the user-chosen folder
 
 ## Tests
 
-`npm test` runs 152 vitest cases: `src/engine/*.test.ts` covers every
+`npm test` runs 373 vitest cases across 21 files: `src/engine/*.test.ts` covers every
 expression class, both languages, deterministic injected rates, goal seek,
 historical rates (injected), date-format literals/display (dedicated engines
 with an explicit `dateFormat`, since the default "system" format depends on

ARCHITECTURE.ru.md

@@ -24,12 +24,16 @@ src/
     editor.ts        обвязка CodeMirror 6: подсветка, оверлей результатов, копирование
     search.ts        оверлей поиска по всем листам (текст + запросы по значению)
     export.ts        рендерит лист + результаты в PNG (буфер обмена/файл)
+    sparkline.ts     рендер SVG-спарклайна для результатов `chart`
     app.css          темы (светлая/тёмная через CSS-переменные)
   main.ts            запуск приложения: документы, настройки, строка статуса, dnd
+  workspace.ts       межлистовые ссылки: кэш экспортов, обнаружение циклов
   storage.ts         команды Tauri / запасной вариант на localStorage
-  extensions.ts      запускает пользовательские .js-файлы через движок
+  extensions.ts      запускает пользовательские .js-файлы в песочнице
+                     QuickJS/WASM, мост к API numi.* движка
   i18n.ts            строки интерфейса (en/ru)
   updater.ts         проверка tauri-plugin-updater, установка + перезапуск
+  logger.ts          тонкая обёртка над console (info/warn/error)
 src-tauri/
   src/main.rs        трей, скрытие в трей, команды хранилища, загрузка курсов
                      (open.er-api.com + CoinGecko + Yahoo Finance v8 chart)
@@ -216,6 +220,40 @@ src-tauri/
   удалённые листы становятся `.numi`-файлами в `backups/deleted/` и удаляются по возрасту.
   Сохранение откладывается на 400 мс.
 
+## Платформы и упаковка
+
+- Одна кодовая база, три десктопных платформы. Всё общее лежит в
+  `tauri.conf.json`, платформенные куски — в `tauri.windows.conf.json`,
+  `tauri.linux.conf.json` и `tauri.macos.conf.json`, которые Tauri накладывает
+  поверх базового конфига (JSON Merge Patch) в зависимости от собираемой цели.
+  Каждый задаёт только `bundle.targets` и опции своего упаковщика: NSIS на
+  Windows, deb/rpm/AppImage на Linux, .app/.dmg на macOS.
+- `release.yml` собирает пять артефактов на трёх видах раннеров: Windows x64 и
+  arm64, Linux x64 (`ubuntu-22.04` — самый старый раннер с webkit2gtk-4.1, что
+  держит планку glibc низко), macOS arm64 и x64. Две отдельные macOS-цели вместо
+  `universal-apple-darwin`: так же, как Windows уже собирается по архитектурам,
+  вдвое меньше вес загрузки, и апдейтер получает ключи `darwin-aarch64` /
+  `darwin-x86_64`, которые ищет по умолчанию.
+- Вся матрица остаётся `max-parallel: 1`. Все джобы отдают артефакты в *один и
+  тот же* объект GitHub Release, а проверка find-or-create в tauri-action гонит,
+  если две джобы доходят до неё одновременно — добавление платформ это
+  ограничение не сняло, а распространило на большее число джоб.
+- Подписи ОС нет нигде. Windows выходит неподписанным; macOS подписан *ad-hoc*
+  (`bundle.macOS.signingIdentity: "-"`) — сертификат Apple для этого не нужен, но
+  без него Apple Silicon вообще откажется запускать скачанный бинарник (сочтёт
+  повреждённым, а не просто предупредит). Gatekeeper в любом случае попросит
+  пользователя разрешить приложение при первом запуске.
+- `bundle.fileAssociations` покрывает `.numi`/`.sum` на Windows (записи в реестр
+  из NSIS) и macOS (`CFBundleDocumentTypes`). На Linux он не даёт ничего
+  полезного: там для регистрации расширения нужен ещё XML для shared-mime-info,
+  который Tauri не генерирует, так что `.numi` открываются перетаскиванием в
+  окно, а не из файлового менеджера.
+- `icons/icon.icns` создаёт `scripts/gen-icon.ts` рядом с PNG и `.ico`, вручную
+  и без зависимостей: магия `icns` + общая длина, дальше по чанку
+  `[OSType][длина][PNG]` на размер, с современными PNG-тегами, которые выдаёт
+  `iconutil` (`icp4`/`icp5`, `ic07`–`ic14`). После правки картинки перегенерить
+  через `npm run icons`.
+
 ## Автообновление
 
 - `updater.ts` вызывает `check()` из `tauri-plugin-updater` при запуске; если
@@ -244,7 +282,9 @@ src-tauri/
   тике интервала, так что переключение прямо во время работы срабатывает
   сразу); ручная кнопка тумблер игнорирует и работает всегда.
 - Эндпоинт обновлений — `latest.json`, публикуемый вместе с каждым GitHub
-  Release. `release.yml` подписывает обе архитектуры парой ключей minisign:
+  Release. `release.yml` подписывает артефакт обновления каждой платформы парой
+  ключей minisign (это собственная подпись обновлений Tauri, к подписи кода в ОС
+  отношения не имеет):
   публичная половина зашита в `tauri.conf.json`; приватная половина + пароль
   живут только как секреты репозитория `TAURI_SIGNING_PRIVATE_KEY(_PASSWORD)`
   (write-only — в репозитории нет постоянной копии). Потеря этого ключа
@@ -267,7 +307,7 @@ src-tauri/
 
 ## Тесты
 
-`npm test` запускает 152 vitest-кейса: `src/engine/*.test.ts` покрывает все
+`npm test` запускает 373 vitest-кейса в 21 файле: `src/engine/*.test.ts` покрывает все
 классы выражений, оба языка, детерминированные инжектированные курсы, поиск
 неизвестного, исторические курсы (инжектированные), литералы и отображение
 форматов дат (отдельные движки с явным `dateFormat` — формат «system» по

README.md

@@ -29,16 +29,29 @@ Works in **English and Russian** at the same time: `5 метров в см`, `20
 
 ## Install
 
-Grab the latest `Summarum_*_x64-setup.exe` (or `arm64-setup.exe` on Windows
+Grab the build for your system from [Releases](../../releases). The whole app
-on ARM) from [Releases](../../releases), run it, done. The whole app is
+is about 2 MB and checks for updates on its own after that.
-about 2 MB. It checks for updates on its own after that.
+
+- **Windows** — `Summarum_*_x64-setup.exe` (or `arm64-setup.exe` on Windows on
+  ARM). Run it, done.
+- **Linux** — `.AppImage` (`chmod +x`, then run) or the `.deb`/`.rpm` if you'd
+  rather install it properly. Self-updating only works on the AppImage; deb and
+  rpm are updated by downloading the next one.
+- **macOS** — `.dmg`, Apple Silicon or Intel. These builds are not signed with
+  an Apple Developer certificate, so the first launch has to be a right-click →
+  **Open** rather than a double-click (or run
+  `xattr -cr /Applications/Summarum.app` once in a terminal). Every launch after
+  that is normal.
 
 Requirements:
 
-- **Windows 10 (1803+) or Windows 11**, 64-bit.
+- **Windows 10 (1803+) or Windows 11**, 64-bit, plus the
-- **[WebView2 Runtime](https://developer.microsoft.com/en-us/microsoft-edge/webview2/)** —
+  **[WebView2 Runtime](https://developer.microsoft.com/en-us/microsoft-edge/webview2/)** —
   already part of Windows 11 and most updated Windows 10 systems; if it's
   missing, the installer downloads it automatically.
+- **Linux** with `webkit2gtk-4.1` (Ubuntu 22.04+, Debian 12+, Fedora 36+) and
+  `libayatana-appindicator3` for the tray icon.
+- **macOS 10.13** or newer.
 - Internet connection is only needed for live rates and market data — everything
   else works offline (rates fall back to a cached/bundled snapshot).
 
@@ -130,7 +143,7 @@ auto-derived one) so the reference doesn't break when its first line changes.
 
 ## Extensions
 
-> **Note:** extensions run as trusted local scripts with access to your files. Only load code you wrote or fully trust.
+> **Note:** extensions run inside a WebAssembly sandbox — no file, network or app access, only the `numi` API below. A script that hangs is cut off; a script that fails is skipped.
 
 Drop a `.js` file into the extensions folder (Settings → Extensions folder)
 and restart. The API is compatible with Numi extensions:
@@ -156,7 +169,7 @@ see [ARCHITECTURE.md](ARCHITECTURE.md).
 
 ```bash
 npm install
-npm test               # engine tests (152 cases)
+npm test               # engine tests (373 cases)
 npm run tauri dev      # run the app
 npm run tauri build    # build the installer
 ```
@@ -165,19 +178,28 @@ To build from source you need:
 
 - [Node.js](https://nodejs.org/) 22.6 or newer (`npm run icons` relies on
   Node's built-in TypeScript support)
-- [Rust](https://rustup.rs/) (stable, MSVC toolchain)
+- [Rust](https://rustup.rs/), stable
-- [Visual Studio Build Tools](https://visualstudio.microsoft.com/visual-cpp-build-tools/)
+- On Windows: the MSVC toolchain plus
+  [Visual Studio Build Tools](https://visualstudio.microsoft.com/visual-cpp-build-tools/)
   with the "Desktop development with C++" workload (the MSVC linker)
+- On Linux: `libwebkit2gtk-4.1-dev`, `libayatana-appindicator3-dev`,
+  `librsvg2-dev`, `libxdo-dev`, `libssl-dev`, `patchelf` and a C toolchain
+- On macOS: Xcode Command Line Tools
 - See the [Tauri prerequisites](https://tauri.app/start/prerequisites/) page
   if anything refuses to compile
 
+`npm run tauri build` produces whatever the host platform bundles — NSIS on
+Windows, deb/rpm/AppImage on Linux, .app/.dmg on macOS. Cross-compiling
+between the three is not supported; the release workflow builds each on its
+own runner.
+
 Stack: [Tauri 2](https://tauri.app) + TypeScript + CodeMirror 6.
 
 ## Credits
 
 Inspired by the excellent [Numi](https://numi.app) by Dmitry Nikolaev —
 if you're on macOS, buy it. Summarum is an independent project, built from
-scratch for Windows.
+scratch for Windows, Linux and macOS.
 
 ## License
 

README.ru.md

@@ -27,14 +27,28 @@ AAPL в USD                     → $213.55
 
 ## Установка
 
-Скачай последний `Summarum_*_x64-setup.exe` (или `arm64-setup.exe` для Windows on ARM) из [Releases](../../releases), запусти — готово. Весь установщик около 2 МБ. Дальше обновления проверяются сами.
+Скачай сборку под свою систему из [Releases](../../releases). Приложение весит
+около 2 МБ, дальше обновления проверяются сами.
+
+- **Windows** — `Summarum_*_x64-setup.exe` (или `arm64-setup.exe` для Windows on
+  ARM). Запусти — готово.
+- **Linux** — `.AppImage` (`chmod +x` и запускай) либо `.deb`/`.rpm`, если хочется
+  поставить нормальным пакетом. Самообновление работает только у AppImage, deb и
+  rpm обновляются скачиванием следующей версии.
+- **macOS** — `.dmg` для Apple Silicon или Intel. Сборки не подписаны сертификатом
+  Apple Developer, поэтому первый запуск — правый клик → **Открыть**, а не двойной
+  клик (либо один раз выполнить `xattr -cr /Applications/Summarum.app` в терминале).
+  Дальше запускается как обычно.
 
 Требования:
 
-- **Windows 10 (1803+) или Windows 11**, 64-бит.
+- **Windows 10 (1803+) или Windows 11**, 64-бит, и
-- **[WebView2 Runtime](https://developer.microsoft.com/en-us/microsoft-edge/webview2/)** —
+  **[WebView2 Runtime](https://developer.microsoft.com/en-us/microsoft-edge/webview2/)** —
   уже встроен в Windows 11 и большинство обновлённых Windows 10; если отсутствует,
   установщик скачает его автоматически.
+- **Linux** с `webkit2gtk-4.1` (Ubuntu 22.04+, Debian 12+, Fedora 36+) и
+  `libayatana-appindicator3` для иконки в трее.
+- **macOS 10.13** или новее.
 - Интернет нужен только для живых курсов и рыночных данных — всё остальное работает офлайн
   (курсы берутся из кэша или встроенного снимка).
 
@@ -125,7 +139,7 @@ AAPL в USD                     → $213.55
 
 ## Расширения
 
-> **Внимание:** расширения запускаются как доверенные локальные скрипты с доступом к вашим файлам. Загружайте только код, который вы написали сами или полностью доверяете.
+> **Внимание:** расширения выполняются в WebAssembly-песочнице — без доступа к файлам, сети и приложению, только API `numi` ниже. Зависший скрипт прерывается, упавший — пропускается.
 
 Брось `.js`-файл в папку расширений (Настройки → Extensions folder) и перезапусти.
 API совместим с расширениями Numi:
@@ -151,7 +165,7 @@ numi.addFunction({ id: "гипот", phrases: "гипот" },
 
 ```bash
 npm install
-npm test               # тесты движка (152 кейса)
+npm test               # тесты движка (373 кейса)
 npm run tauri dev      # запустить приложение
 npm run tauri build    # собрать установщик
 ```
@@ -159,17 +173,25 @@ npm run tauri build    # собрать установщик
 Для сборки нужны:
 
 - [Node.js](https://nodejs.org/) 22.6 или новее
-- [Rust](https://rustup.rs/) (stable, MSVC toolchain)
+- [Rust](https://rustup.rs/), stable
-- [Visual Studio Build Tools](https://visualstudio.microsoft.com/visual-cpp-build-tools/)
+- На Windows: toolchain MSVC и
+  [Visual Studio Build Tools](https://visualstudio.microsoft.com/visual-cpp-build-tools/)
   с компонентом «Desktop development with C++» (нужен линковщик MSVC)
+- На Linux: `libwebkit2gtk-4.1-dev`, `libayatana-appindicator3-dev`,
+  `librsvg2-dev`, `libxdo-dev`, `libssl-dev`, `patchelf` и компилятор C
+- На macOS: Xcode Command Line Tools
 - Если что-то не собирается — см. [Tauri prerequisites](https://tauri.app/start/prerequisites/)
 
+`npm run tauri build` собирает то, что умеет хост-платформа: NSIS на Windows,
+deb/rpm/AppImage на Linux, .app/.dmg на macOS. Кросс-компиляция между ними не
+поддерживается — релизный workflow собирает каждую платформу на своём раннере.
+
 Стек: [Tauri 2](https://tauri.app) + TypeScript + CodeMirror 6.
 
 ## Благодарность
 
 Вдохновлён [Numi](https://numi.app) от Дмитрия Николаева —
-если ты на macOS, купи его. Summarum — независимый проект, написанный с нуля для Windows.
+если ты на macOS, купи его. Summarum — независимый проект, написанный с нуля для Windows, Linux и macOS.
 
 ## Лицензия
 

index.html

@@ -9,31 +9,31 @@
     <div id="app">
       <aside id="sidebar" class="hidden">
         <div id="doc-list"></div>
-        <button id="new-doc" title="New document">+</button>
+        <button id="new-doc" title="New document" aria-label="New document">+</button>
       </aside>
       <main id="content">
         <div id="titlebar" data-tauri-drag-region>
-          <button id="toggle-sidebar" title="Documents (Ctrl+B)">☰</button>
+          <button id="toggle-sidebar" title="Documents (Ctrl+B)" aria-label="Documents">☰</button>
-          <input id="doc-title" spellcheck="false" autocomplete="off" />
+          <input id="doc-title" spellcheck="false" autocomplete="off" aria-label="Document title" />
           <span class="spacer" data-tauri-drag-region></span>
-          <button id="open-search" title="Search all sheets (Ctrl+F)">🔍︎</button>
+          <button id="open-search" title="Search all sheets (Ctrl+F)" aria-label="Search all sheets">🔍︎</button>
-          <button id="open-settings" title="Settings">⚙</button>
+          <button id="open-settings" title="Settings" aria-label="Settings">⚙</button>
           <div id="win-controls">
-            <button id="win-min" title="Minimize">─</button>
+            <button id="win-min" title="Minimize" aria-label="Minimize">─</button>
-            <button id="win-close" title="Hide to tray">✕</button>
+            <button id="win-close" title="Hide to tray" aria-label="Hide to tray">✕</button>
           </div>
         </div>
         <div id="editor-wrap">
           <div id="editor"></div>
           <div id="results"></div>
-          <div id="col-divider" title="Drag to resize"></div>
+          <div id="col-divider" title="Drag to resize" aria-label="Drag to resize results column"></div>
         </div>
         <div id="statusbar">
           <span id="rates-info" title=""></span>
-          <span id="market-info" title="" style="display:none"></span>
+          <span id="market-info" title="" class="d-none"></span>
           <span class="spacer"></span>
           <div id="export-wrap">
-            <button id="export-btn" title="Export">⤓</button>
+            <button id="export-btn" title="Export" aria-label="Export">⤓</button>
             <div id="export-menu" class="hidden">
               <button data-action="image" data-i18n="exportImage">Copy as image</button>
               <button data-action="copy" data-i18n="exportCopy">Copy sheet</button>
@@ -151,7 +151,7 @@
       </div>
       <div id="search-overlay" class="hidden">
         <div class="search-box">
-          <input id="search-input" type="text" autocomplete="off" spellcheck="false" />
+          <input id="search-input" type="text" autocomplete="off" spellcheck="false" aria-label="Search sheets" />
           <div id="search-results"></div>
         </div>
       </div>

package-lock.json

@@ -1,18 +1,19 @@
 {
   "name": "summarum",
-  "version": "1.2.0",
+  "version": "1.2.9",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "summarum",
-      "version": "1.2.0",
+      "version": "1.2.9",
       "dependencies": {
         "@codemirror/autocomplete": "^6.18.0",
         "@codemirror/commands": "^6.8.0",
         "@codemirror/language": "^6.10.0",
         "@codemirror/state": "^6.5.0",
         "@codemirror/view": "^6.36.0",
+        "@jitl/quickjs-singlefile-browser-release-sync": "^0.32.0",
         "@lezer/highlight": "^1.2.0",
         "@tauri-apps/api": "^2.5.0",
         "@tauri-apps/plugin-autostart": "^2.3.0",
@@ -21,7 +22,8 @@
         "@tauri-apps/plugin-opener": "^2.2.0",
         "@tauri-apps/plugin-process": "^2.3.1",
         "@tauri-apps/plugin-updater": "^2.10.1",
-        "decimal.js": "^10.4.3"
+        "decimal.js": "^10.4.3",
+        "quickjs-emscripten-core": "^0.32.0"
       },
       "devDependencies": {
         "@tauri-apps/cli": "^2.5.0",
@@ -532,6 +534,21 @@
         "node": ">=18"
       }
     },
+    "node_modules/@jitl/quickjs-ffi-types": {
+      "version": "0.32.0",
+      "resolved": "https://registry.npmjs.org/@jitl/quickjs-ffi-types/-/quickjs-ffi-types-0.32.0.tgz",
+      "integrity": "sha512-v9T+GQpmk43VDJ7d72sf0Nexhk+ArvtUihW27dy7lqAl0zBObFKtSBBIm5RBjwIhE8VwsPPm9PNuvPvNqLWUEg==",
+      "license": "MIT"
+    },
+    "node_modules/@jitl/quickjs-singlefile-browser-release-sync": {
+      "version": "0.32.0",
+      "resolved": "https://registry.npmjs.org/@jitl/quickjs-singlefile-browser-release-sync/-/quickjs-singlefile-browser-release-sync-0.32.0.tgz",
+      "integrity": "sha512-Hfdl7rh8dzxNWFRiYAYNbhn0RMF1/tO6SMH2mUW0aTibqwaAtqPRbi4WkwaIDlhNz8Z4dksJi1Zjl1R54Jsc/Q==",
+      "license": "MIT",
+      "dependencies": {
+        "@jitl/quickjs-ffi-types": "0.32.0"
+      }
+    },
     "node_modules/@jridgewell/sourcemap-codec": {
       "version": "1.5.5",
       "resolved": "https://registry.npmjs.org/@jridgewell/sourcemap-codec/-/sourcemap-codec-1.5.5.tgz",
@@ -1625,9 +1642,9 @@
       "license": "MIT"
     },
     "node_modules/nanoid": {
-      "version": "3.3.12",
+      "version": "3.3.18",
-      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.12.tgz",
+      "resolved": "https://registry.npmjs.org/nanoid/-/nanoid-3.3.18.tgz",
-      "integrity": "sha512-ZB9RH/39qpq5Vu6Y+NmUaFhQR6pp+M2Xt76XBnEwDaGcVAqhlvxrl3B2bKS5D3NH3QR76v3aSrKaF/Kiy7lEtQ==",
+      "integrity": "sha512-DTg4MJbGMWkfi6VZFdNt2/caMbQy4Ou+Op/hJQvGEWcnVfoA1QA+xzRKAzw9jD6+GVOOeYr/mIcuDSdug6F6+w==",
       "dev": true,
       "funding": [
         {
@@ -1681,9 +1698,9 @@
       }
     },
     "node_modules/postcss": {
-      "version": "8.5.15",
+      "version": "8.5.24",
-      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.15.tgz",
+      "resolved": "https://registry.npmjs.org/postcss/-/postcss-8.5.24.tgz",
-      "integrity": "sha512-FfR8sjd4em2T6fb3I2MwAJU7HWVMr9zba+enmQeeWFfCbm+UOC/0X4DS8XtpUTMwWMGbjKYP7xjfNekzyGmB3A==",
+      "integrity": "sha512-8RyVklq0owXUTa4xlpzu4l9AaVKIdQvAcOHZWaMh98HgySsUtxRVf/chRe3dsSLqb6i40BzGRzEUddRaI+9TSw==",
       "dev": true,
       "funding": [
         {
@@ -1701,7 +1718,7 @@
       ],
       "license": "MIT",
       "dependencies": {
-        "nanoid": "^3.3.12",
+        "nanoid": "^3.3.16",
         "picocolors": "^1.1.1",
         "source-map-js": "^1.2.1"
       },
@@ -1709,6 +1726,15 @@
         "node": "^10 || ^12 || >=14"
       }
     },
+    "node_modules/quickjs-emscripten-core": {
+      "version": "0.32.0",
+      "resolved": "https://registry.npmjs.org/quickjs-emscripten-core/-/quickjs-emscripten-core-0.32.0.tgz",
+      "integrity": "sha512-QFnPfjFey8EqknSrSxe1hZrf1/8z7/6s1QzGOmKo6++02r7QRRX7ZoyNaZh7JuVjWsVW87KnQrbZqnHkOAzUyg==",
+      "license": "MIT",
+      "dependencies": {
+        "@jitl/quickjs-ffi-types": "0.32.0"
+      }
+    },
     "node_modules/rollup": {
       "version": "4.61.1",
       "resolved": "https://registry.npmjs.org/rollup/-/rollup-4.61.1.tgz",

package.json

@@ -1,8 +1,8 @@
 {
   "name": "summarum",
   "private": true,
-  "version": "1.2.0",
+  "version": "1.2.9",
-  "description": "Summarum — natural language calculator notebook for Windows",
+  "description": "Summarum — natural language calculator notebook",
   "type": "module",
   "scripts": {
     "dev": "vite",
@@ -19,6 +19,7 @@
     "@codemirror/language": "^6.10.0",
     "@codemirror/state": "^6.5.0",
     "@codemirror/view": "^6.36.0",
+    "@jitl/quickjs-singlefile-browser-release-sync": "^0.32.0",
     "@lezer/highlight": "^1.2.0",
     "@tauri-apps/api": "^2.5.0",
     "@tauri-apps/plugin-autostart": "^2.3.0",
@@ -27,7 +28,8 @@
     "@tauri-apps/plugin-opener": "^2.2.0",
     "@tauri-apps/plugin-process": "^2.3.1",
     "@tauri-apps/plugin-updater": "^2.10.1",
-    "decimal.js": "^10.4.3"
+    "decimal.js": "^10.4.3",
+    "quickjs-emscripten-core": "^0.32.0"
   },
   "devDependencies": {
     "@tauri-apps/cli": "^2.5.0",

scripts/gen-icon.ts

@@ -113,7 +113,7 @@ function draw(size: number): Buffer {
 
 fs.mkdirSync(outDir, { recursive: true });
 const pngs = new Map<number, Buffer>();
-for (const size of [16, 32, 48, 64, 128, 256, 512]) {
+for (const size of [16, 32, 48, 64, 128, 256, 512, 1024]) {
   pngs.set(size, encodePng(size, draw(size)));
 }
 
@@ -154,3 +154,38 @@ function buildIco(sizes: number[]): Buffer {
 
 fs.writeFileSync(path.join(outDir, "icon.ico"), buildIco([16, 32, 48, 64, 128, 256]));
 console.log("icon.ico (6 sizes)");
+
+// .icns: "icns" magic + total length, then [OSType][length incl. header][PNG].
+// Both lengths are big-endian and count their own 8-byte header. The tag set
+// mirrors what `iconutil` emits for a modern .iconset — every ic*/icp* entry
+// below carries a plain PNG payload (10.7+), so no JPEG 2000 encoder is needed.
+const ICNS_ENTRIES: Array<[string, number]> = [
+  ["icp4", 16],
+  ["icp5", 32],
+  ["ic11", 32], // 16@2x
+  ["ic12", 64], // 32@2x
+  ["ic07", 128],
+  ["ic13", 256], // 128@2x
+  ["ic08", 256],
+  ["ic14", 512], // 256@2x
+  ["ic09", 512],
+  ["ic10", 1024], // 512@2x
+];
+
+function buildIcns(): Buffer {
+  const parts = ICNS_ENTRIES.map(([tag, size]) => {
+    const data = pngs.get(size)!;
+    const head = Buffer.alloc(8);
+    head.write(tag, 0, 4, "ascii");
+    head.writeUInt32BE(8 + data.length, 4);
+    return Buffer.concat([head, data]);
+  });
+  const body = Buffer.concat(parts);
+  const header = Buffer.alloc(8);
+  header.write("icns", 0, 4, "ascii");
+  header.writeUInt32BE(8 + body.length, 4);
+  return Buffer.concat([header, body]);
+}
+
+fs.writeFileSync(path.join(outDir, "icon.icns"), buildIcns());
+console.log(`icon.icns (${ICNS_ENTRIES.length} entries)`);

src-tauri/Cargo.lock

@@ -1094,6 +1094,21 @@ dependencies = [
  "percent-encoding",
 ]
 
+[[package]]
+name = "futures"
+version = "0.3.32"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b147ee9d1f6d097cef9ce628cd2ee62288d963e16fb287bd9286455b241382d"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "futures-executor",
+ "futures-io",
+ "futures-sink",
+ "futures-task",
+ "futures-util",
+]
+
 [[package]]
 name = "futures-channel"
 version = "0.3.32"
@@ -1101,6 +1116,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "07bbe89c50d7a535e539b8c17bc0b49bdb77747034daa8087407d655f3f7cc1d"
 dependencies = [
  "futures-core",
+ "futures-sink",
 ]
 
 [[package]]
@@ -1168,6 +1184,7 @@ version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "389ca41296e6190b48053de0321d02a77f32f8a5d2461dd38762c0593805c6d6"
 dependencies = [
+ "futures-channel",
  "futures-core",
  "futures-io",
  "futures-macro",
@@ -3021,6 +3038,7 @@ dependencies = [
  "base64 0.22.1",
  "bytes",
  "futures-core",
+ "futures-util",
  "http",
  "http-body",
  "http-body-util",
@@ -3040,12 +3058,14 @@ dependencies = [
  "sync_wrapper",
  "tokio",
  "tokio-rustls",
+ "tokio-util",
  "tower",
  "tower-http",
  "tower-service",
  "url",
  "wasm-bindgen",
  "wasm-bindgen-futures",
+ "wasm-streams 0.4.2",
  "web-sys",
  "webpki-roots",
 ]
@@ -3085,7 +3105,7 @@ dependencies = [
  "url",
  "wasm-bindgen",
  "wasm-bindgen-futures",
- "wasm-streams",
+ "wasm-streams 0.5.0",
  "web-sys",
 ]
 
@@ -3707,9 +3727,10 @@ checksum = "13c2bddecc57b384dee18652358fb23172facb8a2c51ccc10d74c157bdea3292"
 
 [[package]]
 name = "summarum"
-version = "1.2.0"
+version = "1.2.9"
 dependencies = [
  "chrono",
+ "futures",
  "reqwest 0.12.28",
  "serde",
  "serde_json",
@@ -4906,6 +4927,19 @@ dependencies = [
  "wasmparser",
 ]
 
+[[package]]
+name = "wasm-streams"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "15053d8d85c7eccdbefef60f06769760a563c7f0a9d6902a13d35c7800b0ad65"
+dependencies = [
+ "futures-util",
+ "js-sys",
+ "wasm-bindgen",
+ "wasm-bindgen-futures",
+ "web-sys",
+]
+
 [[package]]
 name = "wasm-streams"
 version = "0.5.0"

src-tauri/Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "summarum"
-version = "1.2.0"
+version = "1.2.9"
-description = "Summarum — natural language calculator notebook for Windows"
+description = "Summarum — natural language calculator notebook"
 edition = "2021"
 
 [build-dependencies]
@@ -18,8 +18,9 @@ tauri-plugin-updater = "2"
 tauri-plugin-process = "2"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls"] }
+reqwest = { version = "0.12", default-features = false, features = ["json", "rustls-tls", "stream"] }
 chrono = "0.4"
+futures = "0.3.32"
 
 [profile.release]
 strip = true

src-tauri/extension-sample.js

@@ -1,9 +1,9 @@
-// WARNING: extensions run as trusted local code with full access to your files.
-// Only load scripts you wrote yourself or fully trust.
-
 // Summarum extension example.
 // Drop .js files into this folder and restart the app.
 // API: numi.setVariable, numi.addUnit, numi.addFunction.
+//
+// Scripts run in a WebAssembly sandbox: no files, no network, no app internals,
+// and no console/setTimeout/fetch — only plain JS and the numi API above.
 
 // A global variable usable on any sheet, e.g. `salary * vat`
 // numi.setVariable("vat", { "double": 20 });

src-tauri/src/main.rs

@@ -1,18 +1,29 @@
 // Summarum — Tauri shell: tray, hide-to-tray window, app-data storage,
 // currency rates fetching with an on-disk cache, extension script loading.
-#![cfg_attr(not(debug_assertions), windows_subsystem = "windows")]
+#![cfg_attr(
+    all(not(debug_assertions), target_os = "windows"),
+    windows_subsystem = "windows"
+)]
 
 use serde::{Deserialize, Serialize};
+use std::collections::HashSet;
 use std::fs;
 use std::path::{Path, PathBuf};
+use std::sync::Mutex;
 use std::time::{SystemTime, UNIX_EPOCH};
 use tauri::menu::{Menu, MenuItem};
 use tauri::tray::TrayIconBuilder;
-use tauri::{AppHandle, Emitter, Manager, WindowEvent};
+use tauri::{AppHandle, DragDropEvent, Emitter, Manager, WindowEvent};
+use tauri_plugin_dialog::DialogExt;
 use tauri_plugin_opener::OpenerExt;
 
 const RATES_TTL_SECS: u64 = 3600;
 const SAMPLE_JS: &str = include_str!("../extension-sample.js");
+/// Rust owns this file: it records the data folder the user committed to via
+/// the native picker. `save_file`/`load_file` refuse the name so the frontend
+/// cannot forge its own authorization.
+const DATA_DIR_FILE: &str = "data-dir.txt";
+const MAX_SHEET_BYTES: u64 = 1_000_000;
 
 fn data_dir(app: &AppHandle) -> PathBuf {
     let dir = app.path().app_data_dir().expect("no app data dir");
@@ -20,38 +31,171 @@ fn data_dir(app: &AppHandle) -> PathBuf {
     dir
 }
 
+/// Which folder the frontend may point file operations at.
+///
+/// Every `dir` argument arrives over IPC, where a buggy extension or
+/// compromised webview content can name any path on disk, so a path counts
+/// only when the user proved intent for it: `picked` is the folder just chosen
+/// in the native picker, `active` is the folder in use — plus the one being
+/// migrated away from, so a migration that fails partway leaves the folder the
+/// frontend is still pointing at usable.
+#[derive(Default)]
+struct DataDirGate {
+    picked: Mutex<Option<PathBuf>>,
+    active: Mutex<Vec<PathBuf>>,
+}
+
+fn canon_or_raw(p: &Path) -> PathBuf {
+    let mut normalized = PathBuf::new();
+    for component in p.components() {
+        match component {
+            std::path::Component::ParentDir => {
+                let can_pop = matches!(
+                    normalized.components().next_back(),
+                    Some(std::path::Component::Normal(_))
+                );
+                if can_pop {
+                    normalized.pop();
+                } else if !normalized.has_root() {
+                    normalized.push(component);
+                }
+            }
+            std::path::Component::CurDir => {}
+            _ => normalized.push(component),
+        }
+    }
+    normalized
+}
+
+/// Exact match against an authorized folder, compared canonicalized so a
+/// symlink or ".." spelling cannot stand in for a different path. A subfolder
+/// of an authorized folder is not itself authorized.
+fn path_allowed(candidate: &Path, allowed: &[PathBuf]) -> bool {
+    let c = canon_or_raw(candidate);
+    allowed.iter().any(|a| canon_or_raw(a) == c)
+}
+
+/// The custom folder recorded in the app's own settings.json, if any. Only
+/// read once, to seed the gate on the first run after it was introduced —
+/// settings.json is frontend-writable and is not a trust anchor afterwards.
+fn settings_data_dir(app: &AppHandle) -> Option<PathBuf> {
+    let raw = fs::read_to_string(data_dir(app).join("settings.json")).ok()?;
+    let parsed: serde_json::Value = serde_json::from_str(&raw).ok()?;
+    let d = parsed.get("dataDir")?.as_str()?.trim();
+    (!d.is_empty()).then(|| PathBuf::from(d))
+}
+
+fn seed_data_dir_gate(app: &AppHandle) {
+    let marker = data_dir(app).join(DATA_DIR_FILE);
+    let active = match fs::read_to_string(&marker) {
+        Ok(raw) => {
+            let t = raw.trim();
+            (!t.is_empty()).then(|| PathBuf::from(t))
+        }
+        Err(_) => {
+            // upgrading over an install that predates the gate: adopt the
+            // folder already configured, then stop consulting settings.json
+            let adopted = settings_data_dir(app);
+            let contents = adopted
+                .as_ref()
+                .map(|p| p.to_string_lossy().into_owned())
+                .unwrap_or_default();
+            write_atomic(&marker, &contents).ok();
+            adopted
+        }
+    };
+    *app.state::<DataDirGate>().active.lock().unwrap() = active.into_iter().collect();
+}
+
+/// Let the session use `dir` without yet declaring it the folder to come back
+/// to on the next launch — the previous folder stays usable meanwhile.
+fn authorize_data_dir(app: &AppHandle, dir: &Path) {
+    let gate = app.state::<DataDirGate>();
+    let mut active = gate.active.lock().unwrap();
+    active.retain(|p| p != dir);
+    active.insert(0, dir.to_path_buf());
+    active.truncate(2);
+}
+
+/// Record the folder the migration actually landed in. Only reached once every
+/// file is in place, so a half-finished migration never becomes the folder the
+/// app boots into.
+fn commit_data_dir(app: &AppHandle, dir: &Path) -> Result<(), String> {
+    write_atomic(
+        &data_dir(app).join(DATA_DIR_FILE),
+        dir.to_string_lossy().as_ref(),
+    )?;
+    authorize_data_dir(app, dir);
+    Ok(())
+}
+
 /// Documents live either in the default app-data dir or in a user-chosen
 /// folder (settings stay in app-data — the path itself is stored there).
-fn docs_dir(app: &AppHandle, dir: &Option<String>) -> PathBuf {
+/// Anything other than the default has to clear `DataDirGate` first.
-    match dir {
+fn docs_dir(app: &AppHandle, dir: &Option<String>) -> Result<PathBuf, String> {
-        Some(d) if !d.trim().is_empty() => {
+    let requested = dir.as_deref().map(str::trim).unwrap_or("");
-            let p = PathBuf::from(d);
+    if requested.is_empty() {
-            fs::create_dir_all(&p).ok();
+        return Ok(data_dir(app));
-            p
     }
-        _ => data_dir(app),
+    let candidate = PathBuf::from(requested);
+    let gate = app.state::<DataDirGate>();
+    let allowed: Vec<PathBuf> = {
+        let mut allowed = gate.active.lock().unwrap().clone();
+        allowed.extend(gate.picked.lock().unwrap().clone());
+        allowed
+    };
+    if !path_allowed(&candidate, &allowed) {
+        return Err("data folder was not chosen by the user".into());
     }
+    fs::create_dir_all(&candidate).ok();
+    Ok(candidate)
 }
 
 fn safe_name(name: &str) -> bool {
-    !name.is_empty() && !name.contains(['/', '\\', ':']) && !name.contains("..")
+    let path = Path::new(name);
+    let mut components = path.components();
+    match components.next() {
+        Some(std::path::Component::Normal(_)) if components.next().is_none() => {
+            !name.contains(['/', '\\', ':'])
+        }
+        _ => false,
+    }
 }
 
 #[tauri::command]
-fn write_text_file(path: String, contents: String) -> Result<(), String> {
+fn write_text_file(app: AppHandle, contents: String, is_sum: bool) -> Result<bool, String> {
-    write_atomic(std::path::Path::new(&path), &contents)
+    let (name, ext) = if is_sum {
+        ("Summarum Sheet", "sum")
+    } else {
+        ("Text file", "txt")
+    };
+    if let Some(p) = app
+        .dialog()
+        .file()
+        .add_filter(name, &[ext])
+        .blocking_save_file()
+    {
+        write_atomic(&p.into_path().map_err(|e| e.to_string())?, &contents)?;
+        Ok(true)
+    } else {
+        Ok(false)
+    }
 }
 
 #[tauri::command]
-fn write_image_file(path: String, data_base64: String) -> Result<(), String> {
+fn write_image_file(app: AppHandle, data_base64: String) -> Result<bool, String> {
-    use std::io::Write;
+    if let Some(p) = app
-    let bytes = base64_decode(&data_base64)?;
+        .dialog()
-    let p = std::path::Path::new(&path);
+        .file()
-    let tmp = p.with_extension("tmp");
+        .add_filter("PNG Image", &["png"])
-    std::fs::File::create(&tmp)
+        .blocking_save_file()
-        .and_then(|mut f| f.write_all(&bytes))
+    {
-        .map_err(|e| e.to_string())?;
+        let path = p.into_path().map_err(|e| e.to_string())?;
-    fs::rename(&tmp, p).map_err(|e| e.to_string())
+        write_atomic_bytes(&path, &base64_decode(&data_base64)?)?;
+        Ok(true)
+    } else {
+        Ok(false)
+    }
 }
 
 fn base64_decode(s: &str) -> Result<Vec<u8>, String> {
@@ -72,6 +216,9 @@ fn base64_decode(s: &str) -> Result<Vec<u8>, String> {
         })
         .collect::<Result<_, _>>()?;
     for chunk in bytes.chunks(4) {
+        if chunk.len() < 2 {
+            return Err("invalid base64 padding".into());
+        }
         let b0 = chunk[0];
         let b1 = *chunk.get(1).unwrap_or(&0);
         let b2 = *chunk.get(2).unwrap_or(&0);
@@ -87,16 +234,40 @@ fn base64_decode(s: &str) -> Result<Vec<u8>, String> {
     Ok(out)
 }
 
+static TMP_COUNTER: std::sync::atomic::AtomicUsize = std::sync::atomic::AtomicUsize::new(0);
+
 /// write via a temp file + rename so a crash mid-write cannot corrupt the target
-fn write_atomic(path: &Path, contents: &str) -> Result<(), String> {
+fn write_atomic_bytes(path: &Path, contents: &[u8]) -> Result<(), String> {
-    let tmp = path.with_extension("tmp");
+    let count = TMP_COUNTER.fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+    let tmp = path.with_extension(format!("tmp.{}", count));
     fs::write(&tmp, contents).map_err(|e| e.to_string())?;
     fs::rename(&tmp, path).map_err(|e| e.to_string())
 }
 
+fn write_atomic(path: &Path, contents: &str) -> Result<(), String> {
+    write_atomic_bytes(path, contents.as_bytes())
+}
+
+async fn read_file_async(path: PathBuf) -> Option<String> {
+    tauri::async_runtime::spawn_blocking(move || fs::read_to_string(path).ok())
+        .await
+        .ok()
+        .flatten()
+}
+
+async fn write_atomic_async(path: PathBuf, contents: String) {
+    let _ = tauri::async_runtime::spawn_blocking(move || write_atomic(&path, &contents)).await;
+}
+
+/// settings.json and friends; DATA_DIR_FILE is Rust's own authorization record
+/// and must not be forgeable from the frontend.
+fn writable_name(name: &str) -> bool {
+    safe_name(name) && !name.eq_ignore_ascii_case(DATA_DIR_FILE)
+}
+
 #[tauri::command]
 fn save_file(app: AppHandle, name: String, contents: String) -> Result<(), String> {
-    if !safe_name(&name) {
+    if !writable_name(&name) {
         return Err("bad file name".into());
     }
     write_atomic(&data_dir(&app).join(name), &contents)
@@ -104,7 +275,7 @@ fn save_file(app: AppHandle, name: String, contents: String) -> Result<(), Strin
 
 #[tauri::command]
 fn load_file(app: AppHandle, name: String) -> Result<Option<String>, String> {
-    if !safe_name(&name) {
+    if !writable_name(&name) {
         return Err("bad file name".into());
     }
     let path = data_dir(&app).join(name);
@@ -162,26 +333,46 @@ fn now_secs() -> u64 {
         .as_secs()
 }
 
-fn read_rates_cache(app: &AppHandle) -> Option<RatesCache> {
+async fn read_rates_cache(app: &AppHandle) -> Option<RatesCache> {
-    let raw = fs::read_to_string(data_dir(app).join("rates.json")).ok()?;
+    let raw = read_file_async(data_dir(app).join("rates.json")).await?;
     serde_json::from_str(&raw).ok()
 }
 
+const RATES_RESPONSE_LIMIT: usize = 5 * 1024 * 1024;
+
+/// Reads the body as a stream and aborts as soon as it exceeds `limit`,
+/// instead of buffering an unbounded body in memory before checking its size.
+async fn read_body_capped(resp: reqwest::Response, limit: usize) -> Result<Vec<u8>, String> {
+    use futures::StreamExt;
+    let mut stream = resp.bytes_stream();
+    let mut buf = Vec::new();
+    while let Some(chunk) = stream.next().await {
+        let chunk = chunk.map_err(|e| e.to_string())?;
+        buf.extend_from_slice(&chunk);
+        if buf.len() > limit {
+            return Err("response too large".into());
+        }
+    }
+    Ok(buf)
+}
+
 async fn fetch_rates_online() -> Result<RatesPayload, String> {
-    let client = reqwest::Client::builder()
+    let client = HTTP_CLIENT.get_or_init(|| {
+        reqwest::Client::builder()
             .timeout(std::time::Duration::from_secs(15))
             .build()
-        .map_err(|e| e.to_string())?;
+            .unwrap_or_default()
+    });
 
-    let body: serde_json::Value = client
+    let resp = client
         .get("https://open.er-api.com/v6/latest/USD")
         .send()
         .await
-        .map_err(|e| e.to_string())?
-        .json()
-        .await
         .map_err(|e| e.to_string())?;
 
+    let bytes = read_body_capped(resp, RATES_RESPONSE_LIMIT).await?;
+    let body: serde_json::Value = serde_json::from_slice(&bytes).map_err(|e| e.to_string())?;
+
     if body["result"] != "success" {
         return Err("rates api error".into());
     }
@@ -194,7 +385,8 @@ async fn fetch_rates_online() -> Result<RatesPayload, String> {
         ids.join(",")
     );
     if let Ok(resp) = client.get(&url).send().await {
-        if let Ok(json) = resp.json::<serde_json::Value>().await {
+        if let Ok(bytes) = read_body_capped(resp, RATES_RESPONSE_LIMIT).await {
+            if let Ok(json) = serde_json::from_slice::<serde_json::Value>(&bytes) {
                 for (code, id) in CRYPTO {
                     if let Some(price) = json[id]["usd"].as_f64() {
                         if price > 0.0 {
@@ -204,6 +396,7 @@ async fn fetch_rates_online() -> Result<RatesPayload, String> {
                 }
             }
         }
+    }
 
     Ok(RatesPayload {
         date: body["time_last_update_utc"]
@@ -218,7 +411,7 @@ async fn fetch_rates_online() -> Result<RatesPayload, String> {
 #[tauri::command]
 async fn fetch_rates(app: AppHandle, force: bool) -> Result<RatesPayload, String> {
     if !force {
-        if let Some(cache) = read_rates_cache(&app) {
+        if let Some(cache) = read_rates_cache(&app).await {
             if now_secs().saturating_sub(cache.fetched_at) < RATES_TTL_SECS {
                 let mut payload = cache.payload;
                 payload.fetched_at = cache.fetched_at;
@@ -233,11 +426,12 @@ async fn fetch_rates(app: AppHandle, force: bool) -> Result<RatesPayload, String
                 payload: payload.clone(),
             };
             if let Ok(raw) = serde_json::to_string(&cache) {
-                write_atomic(&data_dir(&app).join("rates.json"), &raw).ok();
+                write_atomic_async(data_dir(&app).join("rates.json"), raw).await;
             }
             Ok(payload)
         }
         Err(e) => read_rates_cache(&app)
+            .await
             .map(|c| {
                 let mut payload = c.payload;
                 payload.fetched_at = c.fetched_at;
@@ -265,7 +459,7 @@ async fn fetch_market_data(
     let cache_path = data_dir(&app).join("market.json");
 
     // try cache first
-    if let Ok(raw) = fs::read_to_string(&cache_path) {
+    if let Some(raw) = read_file_async(cache_path.clone()).await {
         if let Ok(cache) = serde_json::from_str::<MarketCache>(&raw) {
             if now_secs().saturating_sub(cache.fetched_at) < MARKET_TTL_SECS {
                 let syms: std::collections::HashSet<&str> =
@@ -295,24 +489,33 @@ async fn fetch_market_data(
     // v7/finance/quote now requires a cookie+crumb pair Yahoo stopped issuing
     // to plain API clients (returns 401); v8 chart still answers anonymously,
     // one symbol per request.
-    let mut prices = std::collections::HashMap::new();
+    let futures_reqs = symbols.iter().map(|sym| {
-    for sym in &symbols {
+        let client = client.clone();
+        async move {
             let url = format!(
                 "https://query1.finance.yahoo.com/v8/finance/chart/{}?range=1d&interval=1d",
                 sym
             );
-        let Ok(resp) = client.get(&url).send().await else {
+            if let Ok(resp) = client.get(&url).send().await {
-            continue;
+                if let Ok(body) = resp.json::<serde_json::Value>().await {
-        };
+                    if let Some(price) =
-        let Ok(body) = resp.json::<serde_json::Value>().await else {
+                        body["chart"]["result"][0]["meta"]["regularMarketPrice"].as_f64()
-            continue;
+                    {
-        };
-        if let Some(price) = body["chart"]["result"][0]["meta"]["regularMarketPrice"].as_f64() {
                         if price > 0.0 {
-                prices.insert(sym.clone(), price);
+                            return Some((sym.clone(), price));
                         }
                     }
                 }
+            }
+            None
+        }
+    });
+
+    let mut prices = std::collections::HashMap::new();
+    let results = futures::future::join_all(futures_reqs).await;
+    for (sym, price) in results.into_iter().flatten() {
+        prices.insert(sym, price);
+    }
 
     if !prices.is_empty() {
         let cache = MarketCache {
@@ -320,7 +523,7 @@ async fn fetch_market_data(
             prices: prices.clone(),
         };
         if let Ok(raw) = serde_json::to_string(&cache) {
-            write_atomic(&cache_path, &raw).ok();
+            write_atomic_async(cache_path, raw).await;
         }
     }
 
@@ -338,36 +541,13 @@ fn valid_date_str(date: &str) -> bool {
         && parts.iter().all(|p| p.chars().all(|c| c.is_ascii_digit()))
 }
 
-#[tauri::command]
+static HTTP_CLIENT: std::sync::OnceLock<reqwest::Client> = std::sync::OnceLock::new();
-async fn fetch_historical_rates(
+
-    app: AppHandle,
+/// frankfurter quotes everything against the `from=USD` base, so USD itself is
-    date: String,
+/// never in the response and has to be anchored by hand.
-) -> Result<std::collections::HashMap<String, f64>, String> {
+fn parse_rate_map(
-    if !valid_date_str(&date) {
+    raw_rates: &serde_json::Map<String, serde_json::Value>,
-        return Err("invalid date format".into());
+) -> std::collections::HashMap<String, f64> {
-    }
-    let cache_path = data_dir(&app).join(format!("rates-{}.json", date));
-    if let Ok(raw) = fs::read_to_string(&cache_path) {
-        if let Ok(cached) = serde_json::from_str::<std::collections::HashMap<String, f64>>(&raw) {
-            return Ok(cached);
-        }
-    }
-    let client = reqwest::Client::builder()
-        .timeout(std::time::Duration::from_secs(15))
-        .build()
-        .map_err(|e| e.to_string())?;
-    // api.frankfurter.app 301-redirects here now, and the old domain is
-    // flaky over reqwest/rustls-tls — go straight to the stable host
-    let url = format!("https://api.frankfurter.dev/v1/{}?from=USD", date);
-    let body: serde_json::Value = client
-        .get(&url)
-        .send()
-        .await
-        .map_err(|e| e.to_string())?
-        .json()
-        .await
-        .map_err(|e| e.to_string())?;
-    let raw_rates = body["rates"].as_object().ok_or("no rates in response")?;
     let mut rates = std::collections::HashMap::new();
     rates.insert("USD".to_string(), 1.0_f64);
     for (code, val) in raw_rates {
@@ -377,17 +557,123 @@ async fn fetch_historical_rates(
             }
         }
     }
+    rates
+}
+
+#[tauri::command]
+async fn fetch_historical_rates(
+    app: AppHandle,
+    date: String,
+) -> Result<std::collections::HashMap<String, f64>, String> {
+    if !valid_date_str(&date) {
+        return Err("invalid date format".into());
+    }
+    let cache_path = data_dir(&app).join(format!("rates-{}.json", date));
+    if let Some(raw) = read_file_async(cache_path.clone()).await {
+        if let Ok(cached) = serde_json::from_str::<std::collections::HashMap<String, f64>>(&raw) {
+            return Ok(cached);
+        }
+    }
+    let client = HTTP_CLIENT.get_or_init(|| {
+        reqwest::Client::builder()
+            .timeout(std::time::Duration::from_secs(15))
+            .build()
+            .unwrap_or_default()
+    });
+    // api.frankfurter.app 301-redirects here now, and the old domain is
+    // flaky over reqwest/rustls-tls — go straight to the stable host
+    let url = format!("https://api.frankfurter.dev/v1/{}?from=USD", date);
+    let resp = client.get(&url).send().await.map_err(|e| e.to_string())?;
+
+    let bytes = read_body_capped(resp, RATES_RESPONSE_LIMIT).await?;
+    let body: serde_json::Value = serde_json::from_slice(&bytes).map_err(|e| e.to_string())?;
+    let rates = parse_rate_map(body["rates"].as_object().ok_or("no rates in response")?);
     if let Ok(serialized) = serde_json::to_string(&rates) {
-        write_atomic(&cache_path, &serialized).ok();
+        write_atomic_async(cache_path, serialized).await;
     }
     Ok(rates)
 }
 
+#[tauri::command]
+async fn fetch_historical_rates_batch(
+    app: AppHandle,
+    dates: Vec<String>,
+) -> Result<std::collections::HashMap<String, std::collections::HashMap<String, f64>>, String> {
+    let mut results = std::collections::HashMap::new();
+    let mut missing_dates = Vec::new();
+
+    for date in &dates {
+        if !valid_date_str(date) {
+            continue;
+        }
+        let cache_path = data_dir(&app).join(format!("rates-{}.json", date));
+        if let Some(raw) = read_file_async(cache_path).await {
+            if let Ok(cached) = serde_json::from_str::<std::collections::HashMap<String, f64>>(&raw)
+            {
+                results.insert(date.clone(), cached);
+                continue;
+            }
+        }
+        missing_dates.push(date.clone());
+    }
+
+    if missing_dates.is_empty() {
+        return Ok(results);
+    }
+
+    let client = HTTP_CLIENT.get_or_init(|| {
+        reqwest::Client::builder()
+            .timeout(std::time::Duration::from_secs(15))
+            .build()
+            .unwrap_or_default()
+    });
+
+    let mut futures = Vec::new();
+
+    for date in missing_dates {
+        let url = format!("https://api.frankfurter.dev/v1/{}?from=USD", date);
+        let client_clone = client.clone();
+        let app_clone = app.clone();
+
+        futures.push(async move {
+            let mut rate_map = None;
+            if let Ok(resp) = client_clone.get(&url).send().await {
+                if let Ok(bytes) = read_body_capped(resp, RATES_RESPONSE_LIMIT).await {
+                    if let Ok(body) = serde_json::from_slice::<serde_json::Value>(&bytes) {
+                        if let Some(rates_obj) = body["rates"].as_object() {
+                            let daily_rates = parse_rate_map(rates_obj);
+                            let cache_path =
+                                data_dir(&app_clone).join(format!("rates-{}.json", date));
+                            if let Ok(serialized) = serde_json::to_string(&daily_rates) {
+                                write_atomic_async(cache_path, serialized).await;
+                            }
+                            rate_map = Some((date, daily_rates));
+                        }
+                    }
+                }
+            }
+            rate_map
+        });
+    }
+
+    use futures::stream::StreamExt;
+    let fetched_results = futures::stream::iter(futures)
+        .buffer_unordered(5)
+        .collect::<Vec<_>>()
+        .await;
+
+    for (date, rates) in fetched_results.into_iter().flatten() {
+        results.insert(date, rates);
+    }
+
+    Ok(results)
+}
+
 // ---------- documents in the (possibly custom) data folder
 
 #[tauri::command]
 fn load_documents(app: AppHandle, dir: Option<String>) -> Result<Option<String>, String> {
-    let path = docs_dir(&app, &dir).join("documents.json");
+    let path = docs_dir(&app, &dir)?.join("documents.json");
     if !path.exists() {
         return Ok(None);
     }
@@ -398,7 +684,7 @@ fn load_documents(app: AppHandle, dir: Option<String>) -> Result<Option<String>,
 
 #[tauri::command]
 fn save_documents(app: AppHandle, dir: Option<String>, contents: String) -> Result<(), String> {
-    write_atomic(&docs_dir(&app, &dir).join("documents.json"), &contents)
+    write_atomic(&docs_dir(&app, &dir)?.join("documents.json"), &contents)
 }
 
 // ---------- backups
@@ -409,7 +695,7 @@ const SNAPSHOT_KEEP: usize = 14;
 /// before the app writes anything, so it captures yesterday's state.
 #[tauri::command]
 fn run_backups(app: AppHandle, dir: Option<String>, retention_days: u32) -> Result<(), String> {
-    let base = docs_dir(&app, &dir);
+    let base = docs_dir(&app, &dir)?;
     let docs = base.join("documents.json");
     let bdir = base.join("backups");
     fs::create_dir_all(bdir.join("deleted")).map_err(|e| e.to_string())?;
@@ -464,7 +750,7 @@ fn backup_deleted_sheet(
     title: String,
     contents: String,
 ) -> Result<(), String> {
-    let bin = docs_dir(&app, &dir).join("backups").join("deleted");
+    let bin = docs_dir(&app, &dir)?.join("backups").join("deleted");
     fs::create_dir_all(&bin).map_err(|e| e.to_string())?;
     let safe: String = title
         .chars()
@@ -481,12 +767,12 @@ fn backup_deleted_sheet(
         safe,
         chrono::Local::now().format("%Y-%m-%d-%H%M%S")
     );
-    fs::write(bin.join(name), contents).map_err(|e| e.to_string())
+    write_atomic(&bin.join(name), &contents)
 }
 
 #[tauri::command]
 fn open_backups_folder(app: AppHandle, dir: Option<String>) -> Result<(), String> {
-    let bdir = docs_dir(&app, &dir).join("backups");
+    let bdir = docs_dir(&app, &dir)?.join("backups");
     fs::create_dir_all(&bdir).ok();
     app.opener()
         .open_path(bdir.to_string_lossy(), None::<&str>)
@@ -495,9 +781,22 @@ fn open_backups_folder(app: AppHandle, dir: Option<String>) -> Result<(), String
 
 // ---------- data folder migration
 
+/// Gated like every other `dir` argument: without it this is a probe for the
+/// existence of an arbitrary path anywhere on disk.
 #[tauri::command]
-fn data_dir_has_documents(dir: String) -> bool {
+fn data_dir_has_documents(app: AppHandle, dir: String) -> Result<bool, String> {
-    PathBuf::from(dir).join("documents.json").exists()
+    Ok(docs_dir(&app, &Some(dir))?.join("documents.json").exists())
+}
+
+#[tauri::command]
+fn pick_data_dir(app: AppHandle) -> Result<Option<String>, String> {
+    let Some(picked) = app.dialog().file().blocking_pick_folder() else {
+        return Ok(None);
+    };
+    let path = picked.into_path().map_err(|e| e.to_string())?;
+    let canon = fs::canonicalize(&path).map_err(|e| e.to_string())?;
+    *app.state::<DataDirGate>().picked.lock().unwrap() = Some(canon);
+    Ok(Some(path.to_string_lossy().into_owned()))
 }
 
 /// strategy: "move" (copy mine, delete originals), "overwrite" (same, target
@@ -509,17 +808,24 @@ fn migrate_data_dir(
     new_dir: String,
     strategy: String,
 ) -> Result<(), String> {
-    let old = docs_dir(&app, &old_dir);
+    // `old_dir` is exactly as untrusted as `new_dir`: on "move" this function
+    // deletes documents.json and every file under backups/ beneath it, so it
+    // has to clear the gate before anything else happens.
+    let old = docs_dir(&app, &old_dir)?;
     let new = PathBuf::from(&new_dir);
-    fs::create_dir_all(&new).map_err(|e| e.to_string())?;
     // canonicalize: "C:\Data" and "c:\data" are the same folder on Windows
-    let canon_old = fs::canonicalize(&old).unwrap_or_else(|_| old.clone());
+    let canon_new = fs::canonicalize(&new).map_err(|e| e.to_string())?;
-    let canon_new = fs::canonicalize(&new).unwrap_or_else(|_| new.clone());
+    let gate = app.state::<DataDirGate>();
-    if canon_old == canon_new {
+    {
-        return Ok(());
+        let picked = gate.picked.lock().unwrap();
+        if picked.as_deref() != Some(canon_new.as_path()) {
+            return Err("target folder was not chosen by the user".into());
         }
-    if strategy == "use_existing" {
+    }
-        return Ok(());
+    let canon_old = fs::canonicalize(&old).unwrap_or_else(|_| old.clone());
+    if canon_old == canon_new || strategy == "use_existing" {
+        gate.picked.lock().unwrap().take();
+        return commit_data_dir(&app, &canon_new);
     }
     let old_docs = old.join("documents.json");
     if old_docs.exists() {
@@ -541,20 +847,43 @@ fn migrate_data_dir(
             }
         }
     }
+    gate.picked.lock().unwrap().take();
     // originals removed only after everything is actually copied
     if old_docs.exists() {
         fs::remove_file(&old_docs).ok();
     }
+    // one level at a time, files only — a recursive delete of anything named
+    // "backups" is too big a hammer even for a gated path.
+    // run_backups/backup_deleted_sheet only ever write flat files here.
     if all_copied {
-        fs::remove_dir_all(old.join("backups")).ok();
+        for sub in ["backups", "backups/deleted"] {
+            if let Ok(entries) = fs::read_dir(old.join(sub)) {
+                for entry in entries.flatten() {
+                    let p = entry.path();
+                    if p.is_file() {
+                        fs::remove_file(&p).ok();
                     }
-    Ok(())
+                }
+            }
+        }
+    }
+    commit_data_dir(&app, &canon_new)
 }
 
-/// Used by drag&drop: read a calculation/text file from an absolute path.
+/// Paths the OS actually handed us in a window drop event. The frontend can
+/// name any path over IPC, so this is the only proof a read was user-initiated.
+#[derive(Default)]
+struct DroppedFiles(Mutex<HashSet<PathBuf>>);
+
+/// Used by drag&drop: read a calculation/text file dropped onto the window.
 #[tauri::command]
-fn read_text_file(path: String) -> Result<String, String> {
+fn read_text_file(app: AppHandle, path: String) -> Result<String, String> {
-    let p = std::path::PathBuf::from(&path);
+    // compare canonicalized, so a symlink or ".." spelling of an allowed path
+    // cannot stand in for a different file
+    let p = fs::canonicalize(&path).map_err(|e| e.to_string())?;
+    if !app.state::<DroppedFiles>().0.lock().unwrap().contains(&p) {
+        return Err("file was not dropped onto the window".into());
+    }
     let ext = p
         .extension()
         .and_then(|e| e.to_str())
@@ -564,7 +893,7 @@ fn read_text_file(path: String) -> Result<String, String> {
         return Err("unsupported file type".into());
     }
     let meta = fs::metadata(&p).map_err(|e| e.to_string())?;
-    if meta.len() > 1_000_000 {
+    if meta.len() > MAX_SHEET_BYTES {
         return Err("file too large".into());
     }
     fs::read_to_string(p).map_err(|e| e.to_string())
@@ -613,15 +942,22 @@ fn is_sheet_path(path: &str) -> bool {
     lower.ends_with(".numi") || lower.ends_with(".sum")
 }
 
+/// A sheet handed to us by the OS (file association, second launch): same
+/// extension whitelist and size cap `read_text_file` applies to drag&drop.
+fn read_sheet_file(path: &Path) -> Option<String> {
+    if !is_sheet_path(&path.to_string_lossy()) {
+        return None;
+    }
+    if fs::metadata(path).ok()?.len() > MAX_SHEET_BYTES {
+        return None;
+    }
+    fs::read_to_string(path).ok()
+}
+
 /// Contents of a .numi/.sum file passed on the command line (file association).
 #[tauri::command]
 fn get_launch_file() -> Option<String> {
-    let arg = std::env::args().nth(1)?;
+    read_sheet_file(Path::new(&std::env::args().nth(1)?))
-    if is_sheet_path(&arg) {
-        fs::read_to_string(arg).ok()
-    } else {
-        None
-    }
 }
 
 #[tauri::command]
@@ -675,7 +1011,7 @@ fn main() {
     tauri::Builder::default()
         .plugin(tauri_plugin_single_instance::init(|app, args, _cwd| {
             if let Some(path) = args.iter().skip(1).find(|a| is_sheet_path(a)) {
-                if let Ok(content) = fs::read_to_string(path) {
+                if let Some(content) = read_sheet_file(Path::new(path)) {
                     app.emit("open-file", content).ok();
                 }
             }
@@ -693,6 +1029,8 @@ fn main() {
         .plugin(tauri_plugin_dialog::init())
         .plugin(tauri_plugin_updater::Builder::new().build())
         .plugin(tauri_plugin_process::init())
+        .manage(DroppedFiles::default())
+        .manage(DataDirGate::default())
         .invoke_handler(tauri::generate_handler![
             save_file,
             load_file,
@@ -702,9 +1040,11 @@ fn main() {
             backup_deleted_sheet,
             open_backups_folder,
             data_dir_has_documents,
+            pick_data_dir,
             migrate_data_dir,
             fetch_rates,
             fetch_historical_rates,
+            fetch_historical_rates_batch,
             fetch_market_data,
             load_extensions,
             open_extensions_folder,
@@ -717,6 +1057,9 @@ fn main() {
         ])
         .setup(|app| {
             let handle = app.handle().clone();
+            // before the webview can ask for anything, so a frontend-written
+            // settings.json cannot influence an already-seeded gate
+            seed_data_dir_gate(&handle);
             let show = MenuItem::with_id(app, "show", "Show / Hide", true, None::<&str>)?;
             let quit = MenuItem::with_id(app, "quit", "Quit Summarum", true, None::<&str>)?;
             let menu = Menu::with_items(app, &[&show, &quit])?;
@@ -741,15 +1084,25 @@ fn main() {
                     }
                 })
                 .build(app)?;
-            let _ = handle;
             Ok(())
         })
-        .on_window_event(|window, event| {
+        .on_window_event(|window, event| match event {
             // close hides to tray
-            if let WindowEvent::CloseRequested { api, .. } = event {
+            WindowEvent::CloseRequested { api, .. } => {
                 window.hide().ok();
                 api.prevent_close();
             }
+            // runs before the webview gets tauri://drag-drop (that emit only
+            // queues a script eval), so the paths are allowed by the time the
+            // frontend can ask for them
+            WindowEvent::DragDrop(DragDropEvent::Drop { paths, .. }) => {
+                let allowed: HashSet<PathBuf> = paths
+                    .iter()
+                    .filter_map(|p| fs::canonicalize(p).ok())
+                    .collect();
+                *window.state::<DroppedFiles>().0.lock().unwrap() = allowed;
+            }
+            _ => {}
         })
         .run(tauri::generate_context!())
         .expect("error while running Summarum");
@@ -785,6 +1138,137 @@ mod tests {
         assert!(safe_name("rates.json"));
     }
 
+    // writable_name — the frontend must not be able to forge the gate's record
+    #[test]
+    fn writable_name_rejects_the_data_dir_marker() {
+        assert!(!writable_name(DATA_DIR_FILE));
+        assert!(!writable_name("DATA-DIR.TXT"));
+    }
+    #[test]
+    fn writable_name_accepts_ordinary_app_files() {
+        assert!(writable_name("settings.json"));
+        assert!(writable_name("documents.json"));
+    }
+
+    fn temp_subdir(tag: &str) -> PathBuf {
+        let nanos = SystemTime::now()
+            .duration_since(UNIX_EPOCH)
+            .unwrap()
+            .as_nanos();
+        let dir = std::env::temp_dir().join(format!("summarum-test-{}-{}", tag, nanos));
+        fs::create_dir_all(&dir).unwrap();
+        dir
+    }
+
+    // path_allowed — the IPC trust boundary for data-folder paths
+    #[test]
+    fn path_allowed_rejects_when_nothing_is_authorized() {
+        let dir = temp_subdir("gate-empty");
+        assert!(!path_allowed(&dir, &[]));
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn path_allowed_accepts_the_authorized_dir() {
+        let dir = temp_subdir("gate-ok");
+        assert!(path_allowed(&dir, std::slice::from_ref(&dir)));
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn path_allowed_accepts_a_different_spelling_of_the_same_dir() {
+        let dir = temp_subdir("gate-spelling");
+        fs::create_dir_all(dir.join("sub")).unwrap();
+        let detour = dir.join("sub").join("..");
+        assert!(path_allowed(&detour, std::slice::from_ref(&dir)));
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn path_allowed_rejects_an_unrelated_dir() {
+        let allowed = temp_subdir("gate-allowed");
+        let attacker = temp_subdir("gate-attacker");
+        assert!(!path_allowed(&attacker, std::slice::from_ref(&allowed)));
+        fs::remove_dir_all(&allowed).ok();
+        fs::remove_dir_all(&attacker).ok();
+    }
+
+    #[test]
+    fn path_allowed_rejects_a_subdir_of_an_authorized_dir() {
+        let allowed = temp_subdir("gate-parent");
+        let child = allowed.join("child");
+        fs::create_dir_all(&child).unwrap();
+        assert!(!path_allowed(&child, std::slice::from_ref(&allowed)));
+        fs::remove_dir_all(&allowed).ok();
+    }
+
+    #[test]
+    fn path_allowed_rejects_a_missing_dir_that_is_not_authorized() {
+        let allowed = temp_subdir("gate-missing");
+        let ghost = allowed
+            .parent()
+            .unwrap()
+            .join("summarum-test-ghost-does-not-exist");
+        assert!(!path_allowed(&ghost, std::slice::from_ref(&allowed)));
+        fs::remove_dir_all(&allowed).ok();
+    }
+
+    // parse_rate_map
+    #[test]
+    fn parse_rate_map_always_anchors_usd() {
+        let obj = serde_json::json!({});
+        let map = parse_rate_map(obj.as_object().unwrap());
+        assert_eq!(map.get("USD"), Some(&1.0));
+    }
+
+    #[test]
+    fn parse_rate_map_uppercases_codes() {
+        let obj = serde_json::json!({ "eur": 0.9, "Gbp": 0.8 });
+        let map = parse_rate_map(obj.as_object().unwrap());
+        assert_eq!(map.get("EUR"), Some(&0.9));
+        assert_eq!(map.get("GBP"), Some(&0.8));
+    }
+
+    #[test]
+    fn parse_rate_map_skips_nonpositive_and_nonnumeric() {
+        let obj =
+            serde_json::json!({ "EUR": 0.9, "AAA": 0.0, "BBB": -1.5, "CCC": "oops", "DDD": null });
+        let map = parse_rate_map(obj.as_object().unwrap());
+        assert_eq!(map.get("EUR"), Some(&0.9));
+        assert!(!map.contains_key("AAA"));
+        assert!(!map.contains_key("BBB"));
+        assert!(!map.contains_key("CCC"));
+        assert!(!map.contains_key("DDD"));
+    }
+
+    // read_sheet_file — size cap shared with read_text_file
+    #[test]
+    fn read_sheet_file_reads_a_small_sheet() {
+        let dir = temp_subdir("sheet-small");
+        let path = dir.join("calc.numi");
+        fs::write(&path, "2 + 2").unwrap();
+        assert_eq!(read_sheet_file(&path).as_deref(), Some("2 + 2"));
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn read_sheet_file_rejects_an_oversized_sheet() {
+        let dir = temp_subdir("sheet-big");
+        let path = dir.join("calc.numi");
+        fs::write(&path, "x".repeat((MAX_SHEET_BYTES + 1) as usize)).unwrap();
+        assert!(read_sheet_file(&path).is_none());
+        fs::remove_dir_all(&dir).ok();
+    }
+
+    #[test]
+    fn read_sheet_file_rejects_a_foreign_extension() {
+        let dir = temp_subdir("sheet-ext");
+        let path = dir.join("payload.js");
+        fs::write(&path, "alert(1)").unwrap();
+        assert!(read_sheet_file(&path).is_none());
+        fs::remove_dir_all(&dir).ok();
+    }
+
     // is_sheet_path
     #[test]
     fn is_sheet_path_matches_extensions() {

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "Summarum",
-  "version": "1.2.0",
+  "version": "1.2.9",
   "identifier": "app.summarum.calc",
   "build": {
     "beforeDevCommand": "npm run dev",
@@ -23,19 +23,19 @@
       }
     ],
     "security": {
-      "csp": "default-src 'self'; script-src 'self' 'unsafe-eval'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; font-src 'self' data:; connect-src ipc: http://ipc.localhost https://open.er-api.com https://api.coingecko.com https://query1.finance.yahoo.com https://query2.finance.yahoo.com https://api.frankfurter.dev"
+      "csp": "default-src 'self'; script-src 'self' 'wasm-unsafe-eval'; style-src 'self'; img-src 'self' data:; font-src 'self' data:; connect-src ipc: http://ipc.localhost https://open.er-api.com https://api.coingecko.com https://query1.finance.yahoo.com https://query2.finance.yahoo.com https://api.frankfurter.dev"
     }
   },
   "bundle": {
     "active": true,
-    "targets": ["nsis"],
     "createUpdaterArtifacts": true,
     "icon": [
       "icons/32x32.png",
       "icons/128x128.png",
       "icons/128x128@2x.png",
       "icons/icon.png",
-      "icons/icon.ico"
+      "icons/icon.ico",
+      "icons/icon.icns"
     ],
     "fileAssociations": [
       {
@@ -44,13 +44,7 @@
         "description": "Summarum calculation sheet",
         "role": "Editor"
       }
-    ],
+    ]
-    "windows": {
-      "nsis": {
-        "installMode": "currentUser",
-        "languages": ["English", "Russian"]
-      }
-    }
   },
   "plugins": {
     "updater": {

src-tauri/tauri.linux.conf.json

@@ -0,0 +1,5 @@
+{
+  "bundle": {
+    "targets": ["deb", "rpm", "appimage"]
+  }
+}

src-tauri/tauri.macos.conf.json

@@ -0,0 +1,8 @@
+{
+  "bundle": {
+    "targets": ["app", "dmg"],
+    "macOS": {
+      "signingIdentity": "-"
+    }
+  }
+}

src-tauri/tauri.windows.conf.json

@@ -0,0 +1,11 @@
+{
+  "bundle": {
+    "targets": ["nsis"],
+    "windows": {
+      "nsis": {
+        "installMode": "currentUser",
+        "languages": ["English", "Russian"]
+      }
+    }
+  }
+}

src/engine/datetime.test.ts

@@ -0,0 +1,209 @@
+import { describe, it, expect, vi, afterEach } from "vitest";
+import {
+  detectDateOrder,
+  resolveZone,
+  startOfToday,
+  addToDate,
+  isCalendarUnit,
+} from "./datetime";
+
+describe("datetime", () => {
+  describe("detectDateOrder", () => {
+    afterEach(() => {
+      vi.restoreAllMocks();
+    });
+
+    it("should detect dmy (e.g. en-GB)", () => {
+      expect(detectDateOrder("en-GB")).toBe("dmy");
+    });
+
+    it("should detect mdy (e.g. en-US)", () => {
+      expect(detectDateOrder("en-US")).toBe("mdy");
+    });
+
+    it("should default to dmy if neither is found", () => {
+      const mockFormatToParts = vi.fn().mockReturnValue([
+        { type: "year", value: "2000" },
+      ]);
+
+      const mockDateTimeFormat = vi.spyOn(Intl, "DateTimeFormat").mockImplementation(() => ({
+        formatToParts: mockFormatToParts,
+      }) as any);
+
+      expect(detectDateOrder()).toBe("dmy");
+      mockDateTimeFormat.mockRestore();
+    });
+  });
+
+  describe("resolveZone", () => {
+    it("should resolve 'local' to system timezone", () => {
+      const mockResolvedOptions = vi.fn().mockReturnValue({ timeZone: "America/Los_Angeles" });
+      const mockDateTimeFormat = vi.spyOn(Intl, "DateTimeFormat").mockImplementation(() => ({
+        resolvedOptions: mockResolvedOptions,
+      }) as any);
+
+      expect(resolveZone(["local"])).toBe("America/Los_Angeles");
+      mockDateTimeFormat.mockRestore();
+    });
+
+    it("should resolve known abbreviations", () => {
+      expect(resolveZone(["utc"])).toBe("UTC");
+      expect(resolveZone(["est"])).toBe("America/New_York");
+      expect(resolveZone(["pst"])).toBe("America/Los_Angeles");
+      expect(resolveZone(["jst"])).toBe("Asia/Tokyo");
+    });
+
+    it("should resolve known cities", () => {
+      expect(resolveZone(["new", "york"])).toBe("America/New_York");
+      expect(resolveZone(["london"])).toBe("Europe/London");
+      expect(resolveZone(["tokyo"])).toBe("Asia/Tokyo");
+      expect(resolveZone(["buenos", "aires"])).toBe("America/Argentina/Buenos_Aires");
+    });
+
+    it("should resolve russian cities", () => {
+      expect(resolveZone(["нью", "йорк"])).toBe("America/New_York");
+      expect(resolveZone(["москва"])).toBe("Europe/Moscow");
+    });
+
+    it("should ignore punctuation and case", () => {
+      expect(resolveZone(["New-York"])).toBe("America/New_York");
+      expect(resolveZone(["LONdoN."])).toBe("Europe/London");
+    });
+
+    it("should resolve raw IANA timezone", () => {
+      expect(resolveZone(["Europe", "Berlin"])).toBe("Europe/Berlin");
+      expect(resolveZone(["America", "Argentina", "Mendoza"])).toBe("America/Argentina/Mendoza");
+    });
+
+    it("should return null for unknown timezones", () => {
+      expect(resolveZone(["Unknown", "City"])).toBeNull();
+      expect(resolveZone(["Invalid/Timezone"])).toBeNull();
+    });
+  });
+
+  describe("startOfToday", () => {
+    afterEach(() => {
+      vi.useRealTimers();
+    });
+
+    it("should return midnight of the current day", () => {
+      vi.useFakeTimers();
+      vi.setSystemTime(new Date("2024-05-15T14:30:00Z"));
+
+      const expected = new Date("2024-05-15T14:30:00Z");
+      expected.setHours(0, 0, 0, 0);
+
+      expect(startOfToday()).toBe(expected.getTime());
+    });
+  });
+
+  describe("addToDate", () => {
+    it("should add days", () => {
+      const ms = new Date("2024-01-01T12:00:00Z").getTime();
+      const res = addToDate(ms, 5, "day");
+      expect(new Date(res).toISOString()).toBe("2024-01-06T12:00:00.000Z");
+    });
+
+    it("should add weeks", () => {
+      const ms = new Date("2024-01-01T12:00:00Z").getTime();
+      const res = addToDate(ms, 2, "week");
+      expect(new Date(res).toISOString()).toBe("2024-01-15T12:00:00.000Z");
+    });
+
+    it("should add months", () => {
+      const ms = new Date("2024-01-15T12:00:00Z").getTime();
+      const res = addToDate(ms, 2, "month");
+      expect(new Date(res).toISOString()).toBe("2024-03-15T12:00:00.000Z");
+    });
+
+    it("should clamp end of month correctly", () => {
+      const ms = new Date("2024-01-31T12:00:00Z").getTime();
+      const res = addToDate(ms, 1, "month");
+      // 2024 is a leap year, so Feb 29
+      expect(new Date(res).toISOString()).toBe("2024-02-29T12:00:00.000Z");
+
+      const ms2 = new Date("2023-01-31T12:00:00Z").getTime();
+      const res2 = addToDate(ms2, 1, "month");
+      // 2023 is not a leap year, so Feb 28
+      expect(new Date(res2).toISOString()).toBe("2023-02-28T12:00:00.000Z");
+    });
+
+    it("should add years", () => {
+      const ms = new Date("2024-01-15T12:00:00Z").getTime();
+      const res = addToDate(ms, 3, "year");
+      expect(new Date(res).toISOString()).toBe("2027-01-15T12:00:00.000Z");
+    });
+
+    it("should clamp end of month when adding years to leap day", () => {
+      const ms = new Date("2024-02-29T12:00:00Z").getTime();
+      const res = addToDate(ms, 1, "year");
+      expect(new Date(res).toISOString()).toBe("2025-02-28T12:00:00.000Z");
+    });
+
+    it("should handle unit ids with prefixes", () => {
+      const ms = new Date("2024-01-01T12:00:00Z").getTime();
+      const res = addToDate(ms, 5, "unit:day");
+      expect(new Date(res).toISOString()).toBe("2024-01-06T12:00:00.000Z");
+    });
+
+    it("should return original ms if amount is not an integer", () => {
+      const ms = new Date("2024-01-01T12:00:00Z").getTime();
+      const res = addToDate(ms, 1.5, "day");
+      expect(res).toBe(ms);
+    });
+
+    it("should return original ms for unhandled units", () => {
+      const ms = new Date("2024-01-01T12:00:00Z").getTime();
+      const res = addToDate(ms, 1, "hour");
+      expect(res).toBe(ms);
+    });
+  });
+
+  describe("isCalendarUnit", () => {
+    it("should return true for valid calendar units with integer amounts", () => {
+      expect(isCalendarUnit("day", 1)).toBe(true);
+      expect(isCalendarUnit("week", 5)).toBe(true);
+      expect(isCalendarUnit("month", -2)).toBe(true);
+      expect(isCalendarUnit("year", 10)).toBe(true);
+      expect(isCalendarUnit("unit:day", 1)).toBe(true);
+    });
+
+    it("should return false for floating point amounts", () => {
+      expect(isCalendarUnit("day", 1.5)).toBe(false);
+      expect(isCalendarUnit("month", 0.5)).toBe(false);
+    });
+
+    it("should return false for non-calendar units", () => {
+      expect(isCalendarUnit("hour", 1)).toBe(false);
+      expect(isCalendarUnit("minute", 1)).toBe(false);
+      expect(isCalendarUnit("unit:meter", 1)).toBe(false);
+    });
+
+    it("should handle edge cases for amount", () => {
+      expect(isCalendarUnit("day", 0)).toBe(true);
+      expect(isCalendarUnit("day", Number.MAX_SAFE_INTEGER)).toBe(true);
+      expect(isCalendarUnit("day", Number.MIN_SAFE_INTEGER)).toBe(true);
+
+      expect(isCalendarUnit("day", NaN)).toBe(false);
+      expect(isCalendarUnit("day", Infinity)).toBe(false);
+      expect(isCalendarUnit("day", -Infinity)).toBe(false);
+    });
+
+    it("should handle edge cases for unitId string format", () => {
+      expect(isCalendarUnit("", 1)).toBe(false);
+      expect(isCalendarUnit(":", 1)).toBe(false);
+
+      // string.split(":") behavior:
+      expect(isCalendarUnit("time:month", 1)).toBe(true);
+      expect(isCalendarUnit(":day", 1)).toBe(true);
+      expect(isCalendarUnit("day:", 1)).toBe(false);
+      expect(isCalendarUnit("a:day:c", 1)).toBe(true);
+    });
+
+    it("should return false for case-sensitive mismatch", () => {
+      expect(isCalendarUnit("Day", 1)).toBe(false);
+      expect(isCalendarUnit("YEAR", 1)).toBe(false);
+      expect(isCalendarUnit("MONTH", 1)).toBe(false);
+    });
+  });
+});

src/engine/datetime.ts

@@ -2,8 +2,8 @@
 import { DateOrder } from "./types";
 
 /** Does the OS locale write the day or the month first? (31.12 vs 12/31) */
-export function detectDateOrder(): DateOrder {
+export function detectDateOrder(locale?: string): DateOrder {
-  const parts = new Intl.DateTimeFormat(undefined, { day: "numeric", month: "numeric", year: "numeric" })
+  const parts = new Intl.DateTimeFormat(locale, { day: "numeric", month: "numeric", year: "numeric" })
     .formatToParts(new Date(2000, 11, 31));
   for (const p of parts) {
     if (p.type === "day") return "dmy";
@@ -105,8 +105,13 @@ export function startOfToday(): number {
  * survives DST transitions; months/years clamp to the end of the target
  * month (Jan 31 + 1 month = Feb 28, not Mar 3).
  */
+/** Strips a prefixed unit id ("milli:second") down to its base ("second"). */
+function baseUnitId(unitId: string): string {
+  return unitId.includes(":") ? unitId.split(":")[1] : unitId;
+}
+
 export function addToDate(ms: number, amount: number, unitId: string): number {
-  const baseId = unitId.includes(":") ? unitId.split(":")[1] : unitId;
+  const baseId = baseUnitId(unitId);
   const d = new Date(ms);
   if ((baseId === "day" || baseId === "week") && Number.isInteger(amount)) {
     d.setDate(d.getDate() + amount * (baseId === "week" ? 7 : 1));
@@ -134,6 +139,6 @@ function lastDayOfMonth(d: Date): number {
 }
 
 export function isCalendarUnit(unitId: string, amount: number): boolean {
-  const baseId = unitId.includes(":") ? unitId.split(":")[1] : unitId;
+  const baseId = baseUnitId(unitId);
   return (baseId === "day" || baseId === "week" || baseId === "month" || baseId === "year") && Number.isInteger(amount);
 }

src/engine/edge.test.ts

@@ -13,6 +13,10 @@ function calc(expr: string): string | null {
   return r[r.length - 1].text;
 }
 
+function evaluateText(doc: string): (string | null)[] {
+  return eng.evaluateDocument(doc).map((x) => x.text);
+}
+
 describe("edge cases", () => {
   it("russian mixed sentence", () => {
     expect(calc("потратил 20$ и ещё 5$")).toBe("$25");
@@ -45,11 +49,11 @@ describe("edge cases", () => {
     expect(calc("hello world")).toBe(null);
   });
   it("sum stops at header", () => {
-    const r = eng.evaluateDocument("5\n# section\n10\n20\nsum").map((x) => x.text);
+    const r = evaluateText("5\n# section\n10\n20\nsum");
     expect(r).toEqual(["5", null, "10", "20", "30"]);
   });
   it("variables with units survive math", () => {
-    const r = eng.evaluateDocument("rent = $500\nfood = $200\nrent + food").map((x) => x.text);
+    const r = evaluateText("rent = $500\nfood = $200\nrent + food");
     expect(r).toEqual(["$500", "$200", "$700"]);
   });
   it("big numbers with grouping", () => {
@@ -145,7 +149,7 @@ describe("crypto", () => {
 
 describe("regressions", () => {
   it("a broken line does not kill the document (BigInt from NaN)", () => {
-    const r = eng.evaluateDocument("2+2\nasin(5) & 3\n3+3").map((x) => x.text);
+    const r = evaluateText("2+2\nasin(5) & 3\n3+3");
     expect(r).toEqual(["4", null, "6"]);
   });
   it("non-finite results are suppressed", () => {
@@ -178,8 +182,8 @@ describe("regressions", () => {
     expect(calc("1,234 + 0")).toBe("1,234"); // exactly 3 digits = thousands
   });
   it("single-letter unit names can be variables", () => {
-    expect(eng.evaluateDocument("m = 5\nm * 2").map((x) => x.text)).toEqual(["5", "10"]);
+    expect(evaluateText("m = 5\nm * 2")).toEqual(["5", "10"]);
-    expect(eng.evaluateDocument("t = 100\nt + 20%").map((x) => x.text)).toEqual(["100", "120"]);
+    expect(evaluateText("t = 100\nt + 20%")).toEqual(["100", "120"]);
   });
   it("tiny conversion results show significant digits, not 0", () => {
     expect(calc("1 mm in km")).toBe("0.000001 km");
@@ -199,7 +203,7 @@ describe("regressions", () => {
     expect(calc("4 ^ 50%")).toBe("2");
   });
   it("avg skips incompatible lines in the denominator", () => {
-    expect(eng.evaluateDocument("10 kg\n20 kg\n5 hours\navg").map((x) => x.text)).toEqual(["10 kg", "20 kg", "5 h", "15 kg"]);
+    expect(evaluateText("10 kg\n20 kg\n5 hours\navg")).toEqual(["10 kg", "20 kg", "5 h", "15 kg"]);
   });
   it("calendar month add clamps to month end", () => {
     const doc = eng.evaluateDocument("today + 1 month");
@@ -282,3 +286,44 @@ describe("review fixes", () => {
     });
   });
 });
+
+describe("regression 2026-08-12", () => {
+  it("a deeply nested-parens line nulls out just that line, not the whole document", () => {
+    const deep = "(".repeat(50000) + "1" + ")".repeat(50000);
+    const r = evaluateText(`1+1\n${deep}\n2+2`);
+    expect(r[0]).toBe("2");
+    expect(r[1]).toBeNull();
+    expect(r[2]).toBe("4");
+  });
+
+  it("'5 min' means 5 minutes, not the min() aggregate", () => {
+    expect(calc("5 min")).toBe("5 min");
+    expect(calc("5 мин")).toBe("5 min");
+  });
+  it("standalone 'min'/'max' aggregate lines still work", () => {
+    const r = evaluateText("10\n20\n5\nmin");
+    expect(r).toEqual(["10", "20", "5", "5"]);
+    const r2 = evaluateText("10\n20\n5\nmax");
+    expect(r2).toEqual(["10", "20", "5", "20"]);
+  });
+
+  function unitIdOf(expr: string): string | null {
+    const v = eng.evaluateDocument(expr)[0].value;
+    return v?.kind === "quantity" ? v.unit?.id ?? null : null;
+  }
+  it("ambiguous currency aliases resolve to one deliberate currency; the other needs its full name", () => {
+    expect(unitIdOf("100 Manat")).toBe("AZN");
+    expect(unitIdOf("100 Turkmenistan Manat")).toBe("TMT");
+    expect(unitIdOf("100 манат")).toBe("AZN");
+    expect(unitIdOf("100 туркменский манат")).toBe("TMT");
+    expect(unitIdOf("100 FC")).toBe("CDF");
+    expect(unitIdOf("100 Comorian Franc")).toBe("KMF");
+    // "Som"/"Kwacha" go to the larger economy (UZS/ZMW); the smaller one needs its full name
+    expect(unitIdOf("100 Som")).toBe("UZS");
+    expect(unitIdOf("100 Kyrgyzstani Som")).toBe("KGS");
+    expect(unitIdOf("100 Kwacha")).toBe("ZMW");
+    expect(unitIdOf("100 Malawian Kwacha")).toBe("MWK");
+    expect(unitIdOf("100 квача")).toBe("ZMW");
+    expect(unitIdOf("100 малавийская квача")).toBe("MWK");
+  });
+});

src/engine/engine.test.ts

@@ -1,8 +1,9 @@
 import { describe, it, expect, beforeAll } from "vitest";
 import { SumEngine } from "./index";
-import { qty } from "./types";
+import { qty, EvalError, XRefError } from "./types";
-import type { XRefResolution } from "./evaluator";
+import type { XRefResolution, EvalCtx } from "./evaluator";
-import { formatValue } from "./index";
+import { evaluate } from "./evaluator";
+import { formatValue } from "./formatter";
 
 let eng: SumEngine;
 
@@ -215,6 +216,12 @@ describe("numeral systems", () => {
 });
 
 describe("variables and document context", () => {
+  it("sequence error recovery", () => {
+    eng.addFunction({ id: "throw_err", phrases: "throw_err" }, () => {
+      throw new EvalError("test error");
+    });
+    expect(calc("throw_err(1) 2 hours")).toBe("2 h");
+  });
   it("assignment and reuse", () => {
     expect(calcDoc("x = 5\nx * 2")).toEqual(["5", "10"]);
   });
@@ -328,6 +335,13 @@ describe("extension API", () => {
     eng.addUnit({ id: "horse", phrases: "horse, horses, hrs", baseUnitId: "meter", format: "hrs", ratio: 2.4 });
     expect(calc("2 horses in meters")).toBe("4.8 m");
   });
+  it("addUnit throws on id collision instead of silently corrupting unitsById", () => {
+    expect(() =>
+      eng.addUnit({ id: "horse", phrases: "nag", baseUnitId: "meter", format: "nag", ratio: 99 })
+    ).toThrow(/horse/);
+    // the original registration must survive the failed collision
+    expect(calc("2 horses in meters")).toBe("4.8 m");
+  });
   it("addFunction (zum from Sample.js)", () => {
     eng.addFunction({ id: "zum", phrases: "zum" }, (values) => ({ double: values[0].double + values[1].double }));
     expect(calc("zum(2;3)")).toBe("5");
@@ -417,3 +431,24 @@ describe("cross-sheet references", () => {
     expect(r[0].assign).toBe("rent");
   });
 });
+
+describe("evaluation errors", () => {
+  it("throws EvalError for unknown variable", () => {
+    const ctx = {
+      vars: new Map(),
+      reg: eng.reg,
+      historicalRates: {},
+    } as unknown as EvalCtx;
+    expect(() => evaluate({ k: "var", name: "unknown" }, ctx)).toThrowError(EvalError);
+  });
+
+  it("throws XRefError for unresolved xref", () => {
+    const ctx = {
+      vars: new Map(),
+      reg: eng.reg,
+      historicalRates: {},
+      resolveXRef: () => ({ ok: false, reason: "xref error" }),
+    } as unknown as EvalCtx;
+    expect(() => evaluate({ k: "xref", sheet: "Sheet", key: "key" }, ctx)).toThrowError(XRefError);
+  });
+});

src/engine/evaluator.test.ts

@@ -0,0 +1,90 @@
+import { describe, it, expect } from "vitest";
+import { toBase, fromBase, convertQ, attachUnit } from "./evaluator";
+import { qty, pct, EvalError, Decimal } from "./types";
+import { buildRegistry } from "./registry";
+
+const reg = buildRegistry();
+const getUnit = (id: string) => {
+  const u = reg.unitsById.get(id);
+  if (!u) throw new Error(`unit ${id} not found`);
+  return u;
+};
+
+describe("quantity conversion", () => {
+  it("toBase works", () => {
+    // 1 km = 1000 m
+    const km = getUnit("kilo:meter");
+    const res1 = toBase(qty(2, km));
+    expect(res1.toNumber()).toBe(2000);
+
+    // 0 C = 273.15 K
+    const c = getUnit("celsius");
+    const res2 = toBase(qty(0, c));
+    expect(res2.toNumber()).toBe(273.15);
+
+    // 10 mpg
+    const mpg = getUnit("mpg");
+    const res3 = toBase(qty(10, mpg));
+    expect(res3.toNumber()).toBeCloseTo(23.5215, 4);
+
+    // error on zero for reciprocal
+    expect(() => toBase(qty(0, mpg))).toThrow(EvalError);
+  });
+
+  it("fromBase works", () => {
+    const km = getUnit("kilo:meter");
+    const res1 = fromBase(new Decimal(2000), km);
+    expect(res1.toNumber()).toBe(2);
+
+    const c = getUnit("celsius");
+    const res2 = fromBase(new Decimal(273.15), c);
+    expect(res2.toNumber()).toBe(0);
+
+    const mpg = getUnit("mpg");
+    const res3 = fromBase(new Decimal(23.5215), mpg);
+    expect(res3.toNumber()).toBeCloseTo(10, 4);
+
+    expect(() => fromBase(new Decimal(0), mpg)).toThrow(EvalError);
+  });
+
+  it("convertQ works", () => {
+    const m = getUnit("meter");
+    const km = getUnit("kilo:meter");
+
+    // 2000m -> km
+    const q1 = convertQ(qty(2000, m), km);
+    expect(q1.value.toNumber()).toBe(2);
+    expect(q1.unit?.id).toBe("kilo:meter");
+
+    // c -> f
+    const c = getUnit("celsius");
+    const f = getUnit("fahrenheit");
+    const q2 = convertQ(qty(0, c), f);
+    expect(q2.value.toNumber()).toBeCloseTo(32);
+
+    // fail on mismatched dimensions
+    const kg = getUnit("kilo:gram");
+    expect(() => convertQ(qty(1, m), kg)).toThrow(EvalError);
+  });
+
+  it("attachUnit works", () => {
+    const m = getUnit("meter");
+    const km = getUnit("kilo:meter");
+    const kg = getUnit("kilo:gram");
+
+    // attaching to dimensionless
+    const r1 = attachUnit(qty(2), m);
+    expect(r1).toMatchObject({ kind: "quantity", unit: { id: "meter" } });
+
+    // attaching matching dimension does conversion
+    const r2 = attachUnit(qty(2000, m), km);
+    expect((r2 as any).value.toNumber()).toBe(2);
+    expect((r2 as any).unit?.id).toBe("kilo:meter");
+
+    // attaching mismatched dimension throws
+    expect(() => attachUnit(qty(1, m), kg)).toThrow(EvalError);
+
+    // attaching to non-quantity throws
+    expect(() => attachUnit(pct(50), m)).toThrow(EvalError);
+  });
+});

src/engine/formatter.test.ts

@@ -0,0 +1,88 @@
+import { describe, it, expect } from "vitest";
+import { formatNumber, formatValue } from "./formatter";
+import { Decimal, defaultSettings, qty, pct, DateVal, ChartValue, EngineSettings } from "./types";
+
+describe("formatNumber", () => {
+  it("formats standard numbers", () => {
+    expect(formatNumber(new Decimal("12.345"), defaultSettings)).toBe("12.35");
+    expect(formatNumber(new Decimal("100"), defaultSettings)).toBe("100");
+  });
+
+  it("handles custom group separators", () => {
+    const s: EngineSettings = { ...defaultSettings, groupSeparator: " " };
+    expect(formatNumber(new Decimal("1234567.89"), s)).toBe("1 234 567.89");
+  });
+
+  it("handles custom decimal separators", () => {
+    const s: EngineSettings = { ...defaultSettings, decimalSeparator: "," };
+    expect(formatNumber(new Decimal("12.345"), s)).toBe("12,35");
+  });
+
+  it("handles scientific notation strings automatically", () => {
+    expect(formatNumber(new Decimal("1e25"), defaultSettings)).toBe("1e+25");
+  });
+
+  it("applies significant digits fallback for numbers close to zero", () => {
+    // 0.001 rounded to 0 decimals is 0, but since >= 1e-12, it shows significant digits
+    const s: EngineSettings = { ...defaultSettings, precision: 0 };
+    expect(formatNumber(new Decimal("0.001"), s)).toBe("0.001");
+  });
+
+  it("treats numbers < 1e-12 as conversion noise", () => {
+    const s: EngineSettings = { ...defaultSettings, precision: 2 };
+    expect(formatNumber(new Decimal("1e-13"), s)).toBe("0");
+  });
+});
+
+describe("formatValue", () => {
+  it("formats chart as empty string", () => {
+    const v: ChartValue = { kind: "chart", points: [], unitLabel: null };
+    expect(formatValue(v, defaultSettings)).toBe("");
+  });
+
+  it("formats percent values", () => {
+    expect(formatValue(pct(25.5), defaultSettings)).toBe("25.5%");
+  });
+
+  it("formats dates depending on flags", () => {
+    // 2024-01-01 12:00:00 UTC = 1704110400000
+    const d: DateVal = { kind: "date", ms: 1704110400000, hasTime: false, timeZone: "UTC" };
+    expect(formatValue(d, { ...defaultSettings, dateFormat: "iso" })).toBe("2024-01-01");
+    expect(formatValue(d, { ...defaultSettings, dateFormat: "dmy" })).toBe("01.01.2024");
+    expect(formatValue(d, { ...defaultSettings, dateFormat: "mdy" })).toBe("01/01/2024");
+
+    // Test timeOnly
+    const dTime: DateVal = { kind: "date", ms: 1704110400000, hasTime: true, timeZone: "UTC", timeOnly: true };
+    expect(formatValue(dTime, defaultSettings)).toBe("12:00");
+  });
+
+  it("formats base conversions", () => {
+    expect(formatValue(qty(255, null, "hex"), defaultSettings)).toBe("0xFF");
+    expect(formatValue(qty(-255, null, "hex"), defaultSettings)).toBe("-0xFF");
+    expect(formatValue(qty(5, null, "binary"), defaultSettings)).toBe("0b101");
+    expect(formatValue(qty(8, null, "octal"), defaultSettings)).toBe("0o10");
+  });
+
+  it("formats representations", () => {
+    expect(formatValue(qty(123456, null, "scientific"), defaultSettings)).toBe("1.23e5");
+    expect(formatValue(qty(1234.56, null, "plain"), defaultSettings)).toBe("1234.56");
+    expect(formatValue(qty(0.75, null, "fraction"), defaultSettings)).toBe("3/4");
+    expect(formatValue(qty(14, null, "roman"), defaultSettings)).toBe("XIV");
+  });
+
+  it("formats Roman numerals fallbacks", () => {
+    // Beyond 3999 falls back to formatNumber
+    expect(formatValue(qty(4000, null, "roman"), defaultSettings)).toBe("4,000");
+  });
+
+  it("formats units", () => {
+    const cm = { id: "cm", dimension: "length" as const, ratio: new Decimal(0.01), format: "cm" };
+    expect(formatValue(qty(10, cm), defaultSettings)).toBe("10 cm");
+
+    const degC = { id: "degC", dimension: "temperature" as const, ratio: new Decimal(1), format: "°C" };
+    expect(formatValue(qty(25, degC), defaultSettings)).toBe("25°C");
+
+    const usd = { id: "USD", dimension: "currency" as const, ratio: new Decimal(1), format: "${}" };
+    expect(formatValue(qty(100, usd), defaultSettings)).toBe("$100");
+  });
+});

src/engine/formatter.ts

@@ -74,6 +74,9 @@ export function formatValue(v: Value, s: EngineSettings): string {
 
   // quantity
   if (v.repr === "hex" || v.repr === "binary" || v.repr === "octal") {
+    if (v.value.abs().gte(new Decimal("1e10000"))) {
+      return formatNumber(v.value, s);
+    }
     const int = v.value.toDecimalPlaces(0, Decimal.ROUND_HALF_UP);
     const neg = int.isNegative();
     const abs = int.abs();
@@ -109,6 +112,9 @@ function withUnit(num: string, f: string): string {
 }
 
 /** Best rational approximation via continued fractions: 0.75 -> "3/4". */
+// Native float, not Decimal: the continued-fraction algorithm is tuned to
+// float epsilon by design, and this is display formatting, not arithmetic
+// carried forward into the result.
 function formatFraction(v: Decimal): string {
   const neg = v.isNegative();
   const x = v.abs().toNumber();

src/engine/index.ts

@@ -1,9 +1,10 @@
+import { logger } from "../logger";
 // Public facade: evaluates whole documents line by line and exposes the
 // extension API (numi.addUnit / addFunction / setVariable).
 import { DateOrder, Decimal, EngineSettings, EvalError, Quantity, Unit, Value, XRefError, defaultSettings, qty } from "./types";
 import { Registry, buildRegistry, Completion } from "./registry";
 import { tokenize, Token } from "./tokenizer";
-import { parseLine } from "./parser";
+import { parseLine, ParsedLine } from "./parser";
 import { evaluate, EvalCtx, XRefResolver, toBase, fromBase } from "./evaluator";
 import { formatValue } from "./formatter";
 import { detectDateOrder } from "./datetime";
@@ -118,12 +119,17 @@ export class SumEngine {
         continue;
       }
 
-      const tokens = tokenize(line, this.reg, this.dateOrder);
+      // tokenize/parseLine/evaluate all run under one try/catch: pathological
-      const knownVars = new Set(vars.keys());
+      // input (e.g. stack-overflowing nested parens in the parser) must null
-      const parsed = parseLine(tokens, knownVars, line);
+      // out this one line, not throw past evaluateDocument and kill the rest.
-
+      let tokens: Token[] = [];
+      let parsed: ParsedLine = { expr: null };
       let value: Value | null = null;
       let lineError: string | undefined;
+      try {
+        tokens = tokenize(line, this.reg, this.dateOrder);
+        const knownVars = new Set(vars.keys());
+        parsed = parseLine(tokens, knownVars, line);
         if (parsed.expr) {
           const ctx: EvalCtx = {
             reg: this.reg,
@@ -132,18 +138,23 @@ export class SumEngine {
             historicalRates: this.historicalRates,
             resolveXRef,
           };
-        try {
           value = evaluate(parsed.expr, ctx);
-          // a line without a result beats a dead sheet — swallow everything,
+        }
-          // including extension bugs and BigInt conversion errors
       } catch (e) {
-          if (e instanceof XRefError) lineError = e.message;
+        if (e instanceof XRefError) {
-          else if (!(e instanceof EvalError)) console.warn("evaluate failed:", e);
+          lineError = e.message;
+        } else if (e instanceof EvalError) {
+          // Expected evaluation failure; remain silent
+        } else {
+          // Capture unexpected execution anomalies like BigInt or Range errors
+          lineError = e instanceof Error ? e.message : String(e);
+          logger.warn("evaluate failed:", e);
+        }
+        // a line without a result beats a dead sheet.
         value = null;
       }
       if (value?.kind === "quantity" && !value.value.isFinite()) value = null;
       if (value && parsed.assign) vars.set(parsed.assign, value);
-      }
 
       lineValues.push(value);
       lineKinds.push("normal");
@@ -208,6 +219,7 @@ export class SumEngine {
   addUnit(spec: ExtensionUnitSpec): void {
     const base = this.reg.unitsById.get(spec.baseUnitId) ?? this.currencyBase(spec.baseUnitId);
     if (!base) throw new Error(`numi.addUnit: unknown baseUnitId ${spec.baseUnitId}`);
+    if (this.reg.unitsById.has(spec.id)) throw new Error(`numi.addUnit: id "${spec.id}" is already registered`);
     const unit: Unit = {
       id: spec.id,
       dimension: base.dimension,

src/engine/lexer.test.ts

@@ -0,0 +1,113 @@
+import { describe, it, expect } from "vitest";
+import { lexLine } from "./lexer";
+import { Decimal } from "./types";
+
+describe("lexer", () => {
+  describe("lexLine", () => {
+    it("should lex words and symbols, ignoring spaces", () => {
+      const result = lexLine("hello + world");
+      expect(result).toEqual([
+        { type: "word", raw: "hello", start: 0, end: 5 },
+        { type: "sym", raw: "+", start: 6, end: 7 },
+        { type: "word", raw: "world", start: 8, end: 13 },
+      ]);
+    });
+
+    it("should lex ISO dates", () => {
+      const result = lexLine("2024-12-31");
+      expect(result).toEqual([
+        { type: "date", raw: "2024-12-31", start: 0, end: 10, dateMs: new Date(2024, 11, 31).getTime() },
+      ]);
+    });
+
+    it("should lex dmy dates", () => {
+      const result = lexLine("31.12.2024");
+      expect(result).toEqual([
+        { type: "date", raw: "31.12.2024", start: 0, end: 10, dateMs: new Date(2024, 11, 31).getTime() },
+      ]);
+    });
+
+    it("should lex ambiguous dates as dmy by default", () => {
+      const result = lexLine("01/02/2024");
+      expect(result).toEqual([
+        { type: "date", raw: "01/02/2024", start: 0, end: 10, dateMs: new Date(2024, 1, 1).getTime() },
+      ]);
+    });
+
+    it("should lex ambiguous dates as mdy if specified", () => {
+      const result = lexLine("01/02/2024", "mdy");
+      expect(result).toEqual([
+        { type: "date", raw: "01/02/2024", start: 0, end: 10, dateMs: new Date(2024, 0, 2).getTime() },
+      ]);
+    });
+
+    it("should fallback when invalid dates are encountered", () => {
+      // 2026-13-45 is invalid as a date, should lex as numbers and syms
+      const result = lexLine("2026-13-45");
+      expect(result[0].type).toBe("num");
+      expect(result[0].raw).toBe("2026");
+      expect(result[1].type).toBe("sym");
+      expect(result[1].raw).toBe("-");
+    });
+
+    it("should lex plain integers", () => {
+      const result = lexLine("42");
+      expect(result).toEqual([
+        { type: "num", raw: "42", start: 0, end: 2, value: new Decimal("42"), repr: "decimal" },
+      ]);
+    });
+
+    it("should lex decimal comma numbers", () => {
+      const result = lexLine("42,5");
+      expect(result).toEqual([
+        { type: "num", raw: "42,5", start: 0, end: 4, value: new Decimal("42.5"), repr: "decimal" },
+      ]);
+    });
+
+    it("should lex space-grouped numbers", () => {
+      const result = lexLine("1 000 000,5");
+      expect(result).toEqual([
+        { type: "num", raw: "1 000 000,5", start: 0, end: 11, value: new Decimal("1000000.5"), repr: "decimal" },
+      ]);
+    });
+
+    it("should lex comma-grouped numbers", () => {
+      const result = lexLine("1,000,000.5");
+      expect(result).toEqual([
+        { type: "num", raw: "1,000,000.5", start: 0, end: 11, value: new Decimal("1000000.5"), repr: "decimal" },
+      ]);
+    });
+
+    it("should lex numbers with leading dots", () => {
+      const result = lexLine(".5");
+      expect(result).toEqual([
+        { type: "num", raw: ".5", start: 0, end: 2, value: new Decimal(".5"), repr: "decimal" },
+      ]);
+    });
+
+    it("should lex base numbers (hex, bin, oct)", () => {
+      const hex = lexLine("0xff");
+      expect(hex[0]).toMatchObject({ type: "num", raw: "0xff", value: new Decimal(255), repr: "hex" });
+
+      const bin = lexLine("0b1010");
+      expect(bin[0]).toMatchObject({ type: "num", raw: "0b1010", value: new Decimal(10), repr: "binary" });
+
+      const oct = lexLine("0o77");
+      expect(oct[0]).toMatchObject({ type: "num", raw: "0o77", value: new Decimal(63), repr: "octal" });
+    });
+
+    it("should lex bare cross-references", () => {
+      const result = lexLine("@sheet.key");
+      expect(result).toEqual([
+        { type: "xref", raw: "@sheet.key", start: 0, end: 10, sheet: "sheet", key: "key" },
+      ]);
+    });
+
+    it("should lex bracketed cross-references", () => {
+      const result = lexLine("@[my sheet].key");
+      expect(result).toEqual([
+        { type: "xref", raw: "@[my sheet].key", start: 0, end: 15, sheet: "my sheet", key: "key" },
+      ]);
+    });
+  });
+});

src/engine/lexer.ts

@@ -34,25 +34,12 @@ function validDateMs(y: number, mo: number, d: number): number | null {
     : null;
 }
 
-export function lexLine(text: string, dateOrder: DateOrder = "dmy"): Lex[] {
+function tryLexDate(rest: string, i: number, dateOrder: DateOrder): Lex | null {
-  const out: Lex[] = [];
-  let i = 0;
-  while (i < text.length) {
-    const ch = text[i];
-    if (ch === " " || ch === "\t" || ch === " ") {
-      i++;
-      continue;
-    }
-    const rest = text.slice(i);
-
-    if (ch >= "0" && ch <= "9") {
   const iso = /^(\d{4})-(\d{2})-(\d{2})(?!\d)/.exec(rest);
   if (iso) {
     const ms = validDateMs(Number(iso[1]), Number(iso[2]), Number(iso[3]));
     if (ms !== null) {
-          out.push({ type: "date", raw: iso[0], start: i, end: i + iso[0].length, dateMs: ms });
+      return { type: "date", raw: iso[0], start: i, end: i + iso[0].length, dateMs: ms };
-          i += iso[0].length;
-          continue;
     }
   }
   const dm = SLASH_DOT_DATE_RE.exec(rest);
@@ -64,33 +51,29 @@ export function lexLine(text: string, dateOrder: DateOrder = "dmy"): Lex[] {
     const y = Number(dm[4]);
     const ms = dayFirst ? validDateMs(y, b, a) : validDateMs(y, a, b);
     if (ms !== null) {
-          out.push({ type: "date", raw: dm[0], start: i, end: i + dm[0].length, dateMs: ms });
+      return { type: "date", raw: dm[0], start: i, end: i + dm[0].length, dateMs: ms };
-          i += dm[0].length;
-          continue;
     }
   }
-    }
+  return null;
-    if (ch >= "0" && ch <= "9") {
+}
+
+function tryLexBaseNumber(rest: string, i: number): Lex | null {
   const hex = /^0[xX][0-9a-fA-F]+/.exec(rest);
   if (hex) {
-        out.push({ type: "num", raw: hex[0], start: i, end: i + hex[0].length, value: new Decimal(parseInt(hex[0], 16)), repr: "hex" });
+    return { type: "num", raw: hex[0], start: i, end: i + hex[0].length, value: new Decimal(parseInt(hex[0], 16)), repr: "hex" };
-        i += hex[0].length;
-        continue;
   }
   const bin = /^0[bB][01]+/.exec(rest);
   if (bin) {
-        out.push({ type: "num", raw: bin[0], start: i, end: i + bin[0].length, value: new Decimal(parseInt(bin[0].slice(2), 2)), repr: "binary" });
+    return { type: "num", raw: bin[0], start: i, end: i + bin[0].length, value: new Decimal(parseInt(bin[0].slice(2), 2)), repr: "binary" };
-        i += bin[0].length;
-        continue;
   }
   const oct = /^0[oO][0-7]+/.exec(rest);
   if (oct) {
-        out.push({ type: "num", raw: oct[0], start: i, end: i + oct[0].length, value: new Decimal(parseInt(oct[0].slice(2), 8)), repr: "octal" });
+    return { type: "num", raw: oct[0], start: i, end: i + oct[0].length, value: new Decimal(parseInt(oct[0].slice(2), 8)), repr: "octal" };
-        i += oct[0].length;
-        continue;
   }
-    }
+  return null;
-    if (ch >= "0" && ch <= "9") {
+}
+
+function tryLexDecimalNumber(rest: string, i: number): Lex | null {
   let raw: string | null = null;
   let cleaned = "";
   const sp = NUM_SPACE_GROUPED_RE.exec(rest);
@@ -111,37 +94,65 @@ export function lexLine(text: string, dateOrder: DateOrder = "dmy"): Lex[] {
     cleaned = raw;
   }
   if (raw) {
-        out.push({ type: "num", raw, start: i, end: i + raw.length, value: new Decimal(cleaned), repr: "decimal" });
+    return { type: "num", raw, start: i, end: i + raw.length, value: new Decimal(cleaned), repr: "decimal" };
-        i += raw.length;
-        continue;
-      }
-    }
-    if (ch === "." && /^\.\d/.test(rest)) {
-      const m = /^\.\d+/.exec(rest)!;
-      out.push({ type: "num", raw: m[0], start: i, end: i + m[0].length, value: new Decimal(m[0]), repr: "decimal" });
-      i += m[0].length;
-      continue;
   }
+  return null;
+}
 
-    if (ch === "@") {
+function tryLexDotNumber(rest: string, i: number): Lex | null {
+  if (/^\.\d/.test(rest)) {
+    const m = /^\.\d+/.exec(rest)!;
+    return { type: "num", raw: m[0], start: i, end: i + m[0].length, value: new Decimal(m[0]), repr: "decimal" };
+  }
+  return null;
+}
+
+function tryLexXRef(rest: string, i: number): Lex | null {
   const bracket = /^@\[([^\]]+)\]\.([\p{L}_][\p{L}\d_]*)/u.exec(rest);
   if (bracket) {
-        out.push({ type: "xref", raw: bracket[0], start: i, end: i + bracket[0].length, sheet: bracket[1].trim(), key: bracket[2] });
+    return { type: "xref", raw: bracket[0], start: i, end: i + bracket[0].length, sheet: bracket[1].trim(), key: bracket[2] };
-        i += bracket[0].length;
-        continue;
   }
   const bare = /^@([\p{L}_][\p{L}\d_]*)\.([\p{L}_][\p{L}\d_]*)/u.exec(rest);
   if (bare) {
-        out.push({ type: "xref", raw: bare[0], start: i, end: i + bare[0].length, sheet: bare[1], key: bare[2] });
+    return { type: "xref", raw: bare[0], start: i, end: i + bare[0].length, sheet: bare[1], key: bare[2] };
-        i += bare[0].length;
-        continue;
-      }
   }
+  return null;
+}
 
+function tryLexWord(rest: string, i: number): Lex | null {
   const word = WORD_RE.exec(rest);
   if (word) {
-      out.push({ type: "word", raw: word[0], start: i, end: i + word[0].length });
+    return { type: "word", raw: word[0], start: i, end: i + word[0].length };
-      i += word[0].length;
+  }
+  return null;
+}
+
+export function lexLine(text: string, dateOrder: DateOrder = "dmy"): Lex[] {
+  const out: Lex[] = [];
+  let i = 0;
+  while (i < text.length) {
+    const ch = text[i];
+    if (ch === " " || ch === "\t" || ch === " ") {
+      i++;
+      continue;
+    }
+    const rest = text.slice(i);
+
+    let lex: Lex | null = null;
+    if (ch >= "0" && ch <= "9") {
+      lex = tryLexDate(rest, i, dateOrder) || tryLexBaseNumber(rest, i) || tryLexDecimalNumber(rest, i);
+    } else if (ch === ".") {
+      lex = tryLexDotNumber(rest, i);
+    } else if (ch === "@") {
+      lex = tryLexXRef(rest, i);
+    }
+    if (!lex) {
+      lex = tryLexWord(rest, i);
+    }
+
+    if (lex) {
+      out.push(lex);
+      i += lex.raw.length;
       continue;
     }
 

src/engine/parser.test.ts

@@ -0,0 +1,95 @@
+import { describe, it, expect } from "vitest";
+import { parseLine } from "./parser";
+import { tokenize } from "./tokenizer";
+import { buildRegistry } from "./registry";
+import { Decimal } from "./types";
+
+const reg = buildRegistry();
+
+function parse(line: string, knownVars = new Set<string>()) {
+  const tokens = tokenize(line, reg);
+  return parseLine(tokens, knownVars, line);
+}
+
+describe("parseLine", () => {
+  it("parses basic expressions", () => {
+    const res = parse("2 + 2");
+    expect(res.assign).toBeUndefined();
+    expect(res.expr).toMatchObject({
+      k: "bin",
+      op: "plus",
+      l: { k: "num", v: new Decimal(2) },
+      r: { k: "num", v: new Decimal(2) }
+    });
+  });
+
+  it("parses variable assignment with '='", () => {
+    const res = parse("x = 5 + 3");
+    expect(res.assign).toBe("x");
+    expect(res.expr).toMatchObject({
+      k: "bin",
+      op: "plus",
+      l: { k: "num", v: new Decimal(5) },
+      r: { k: "num", v: new Decimal(3) }
+    });
+  });
+
+  it("parses variable assignment with 'is'", () => {
+    const res = parse("myVar is 10");
+    expect(res.assign).toBe("myVar");
+    expect(res.expr).toMatchObject({
+      k: "num",
+      v: new Decimal(10)
+    });
+  });
+
+  it("rejects invalid variable names for assignment", () => {
+    const res = parse("123 = 5");
+    expect(res.assign).toBeUndefined();
+  });
+
+  it("handles known variables shadowing built-ins", () => {
+    // "m" is normally a unit (meters), but if it's a known variable, it's treated as a word
+    const res = parse("m = 5", new Set(["m"]));
+    expect(res.assign).toBe("m");
+    expect(res.expr).toMatchObject({
+      k: "num",
+      v: new Decimal(5)
+    });
+  });
+
+  it("filters noise words", () => {
+    // "what is 2 + 2" -> "what" and "is" are noise, leaving "2 + 2"
+    const res = parse("what is 2 + 2");
+    expect(res.expr).toMatchObject({
+      k: "bin",
+      op: "plus"
+    });
+  });
+
+  it("keeps words after a conversion operator (e.g., timezones)", () => {
+    // "now in Europe/Berlin"
+    // "Europe/Berlin" should be kept as a timezone, not dropped as noise.
+    const res = parse("now in Europe/Berlin");
+    expect(res.expr).toMatchObject({
+      k: "conv",
+      target: {
+        type: "tz"
+      }
+    });
+  });
+
+  it("parses goal seek expressions", () => {
+    const res = parse("? * 1.2 = 1000");
+    expect(res.expr).toMatchObject({
+      k: "goalseek",
+      lhs: { k: "bin", op: "mul", l: { k: "unknown" }, r: { k: "num", v: new Decimal(1.2) } },
+      rhs: { k: "num", v: new Decimal(1000) }
+    });
+  });
+
+  it("returns null expression for empty or noise-only lines", () => {
+    const res = parse("just some noise");
+    expect(res.expr).toBeNull();
+  });
+});

src/engine/parser.ts

@@ -62,6 +62,18 @@ export function parseLine(tokens: Token[], knownVars: Set<string>, line: string)
     }
   }
 
+  const filtered = filterNoiseTokens(toks, knownVars);
+
+  const goalSeek = tryParseGoalSeek(filtered, knownVars);
+  if (goalSeek) {
+    return { expr: goalSeek };
+  }
+
+  const p = new Parser(filtered, knownVars);
+  return { assign, expr: p.parseSeq() };
+}
+
+function filterNoiseTokens(toks: Token[], knownVars: Set<string>): Token[] {
   // Noise filtering: drop junk and unknown words, but keep words that follow
   // a conversion operator (potential timezone names).
   const filtered: Token[] = [];
@@ -81,7 +93,10 @@ export function parseLine(tokens: Token[], knownVars: Set<string>, line: string)
     afterConv = tk.t === "conv";
     filtered.push(tk);
   }
+  return filtered;
+}
 
+function tryParseGoalSeek(filtered: Token[], knownVars: Set<string>): Node | null {
   // Goal seek: `? * 1.2 = 1000` → find x where lhs(x) = rhs(x)
   const hasUnknown = filtered.some((tk) => tk.t === "unknown");
   if (hasUnknown) {
@@ -89,14 +104,23 @@ export function parseLine(tokens: Token[], knownVars: Set<string>, line: string)
     if (assignIdx >= 0) {
       const lhs = new Parser(filtered.slice(0, assignIdx), knownVars).parseSeq();
       const rhs = new Parser(filtered.slice(assignIdx + 1), knownVars).parseSeq();
-      if (lhs && rhs) return { expr: { k: "goalseek", lhs, rhs } };
+      if (lhs && rhs) return { k: "goalseek", lhs, rhs };
     }
   }
-
+  return null;
-  const p = new Parser(filtered, knownVars);
-  return { assign, expr: p.parseSeq() };
 }
 
+
+const PREC = {
+  CONV: 10,
+  BIT: 20,
+  ADD: 30,
+  MUL: 40,
+  UNARY: 50,
+  POW: 55,
+  POSTFIX: 60,
+};
+
 class Parser {
   private i = 0;
   constructor(private toks: Token[], private vars: Set<string>) {}
@@ -130,7 +154,7 @@ class Parser {
       }
       if (tk.t === "pctop" && (tk.op.startsWith("as_pct") || tk.op.endsWith("what_is")) && items.length > 0) {
         this.i++;
-        const r = this.parseAdd();
+        const r = this.parseExpr(PREC.ADD);
         if (r) {
           items = [{ k: "pctop", op: tk.op, l: mk(), r }];
           continue;
@@ -141,7 +165,7 @@ class Parser {
       if (tk.t === "op" && items.length > 0) {
         const save = this.i;
         this.i++;
-        const r = tk.op === "plus" || tk.op === "minus" ? this.parseMul() : this.parseUnary();
+        const r = tk.op === "plus" || tk.op === "minus" ? this.parseExpr(PREC.MUL) : this.parseExpr(PREC.UNARY);
         if (r) {
           items = [{ k: "bin", op: tk.op, l: mk(), r }];
           continue;
@@ -152,7 +176,7 @@ class Parser {
       if (tk.t === "bitop" && items.length > 0) {
         const save = this.i;
         this.i++;
-        const r = this.parseAdd();
+        const r = this.parseExpr(PREC.ADD);
         if (r) {
           items = [{ k: "bit", op: tk.op, l: mk(), r }];
           continue;
@@ -161,7 +185,7 @@ class Parser {
         continue;
       }
       const before = this.i;
-      const node = this.parseBit();
+      const node = this.parseExpr(PREC.BIT);
       if (node) items.push(node);
       if (this.i === before) this.i++; // skip unparsable token
     }
@@ -169,52 +193,161 @@ class Parser {
     return mk();
   }
 
-  /** bitwise level (one flat precedence, left-assoc): & | xor << >> */
+  /**
-  private parseBit(): Node | null {
+   * Pratt parser implementation for expressions.
-    let l = this.parseAdd();
+   */
-    if (!l) return null;
+  private parseExpr(minPrec: number = 0): Node | null {
-    for (;;) {
+    let tk = this.peek();
-      const tk = this.peek();
+    if (!tk) return null;
-      if (tk?.t !== "bitop") break;
+
-      const save = this.i;
+    let lhs: Node | null = null;
+
+    if (tk.t === "op" && tk.op === "minus") {
       this.i++;
-      const r = this.parseAdd();
+      const x = this.parseExpr(PREC.UNARY);
-      if (!r) {
+      if (!x) return null;
-        this.i = save;
+      lhs = { k: "neg", x };
-        break;
+    } else if (tk.t === "op" && tk.op === "plus") {
-      }
+      this.i++;
-      l = { k: "bit", op: tk.op, l, r };
+      lhs = this.parseExpr(PREC.UNARY);
-    }
+      if (!lhs) return null;
-    return l;
+    } else {
+      lhs = this.parsePrimary();
     }
 
-  /** conversion level: `x in cm`, `x as a % of y`, `x of what is y` */
+    if (!lhs) return null;
-  private parseConv(): Node | null {
+
-    let l = this.parseBit();
+    loop: for (;;) {
-    if (!l) return null;
+      tk = this.peek();
-    for (;;) {
+      if (!tk) break;
-      const tk = this.peek();
+
-      if (tk?.t === "conv") {
+      switch (tk.t) {
+        case "percent": {
+          if (PREC.POSTFIX < minPrec) break loop;
+          this.i++;
+          lhs = { k: "pct", x: lhs };
+          continue loop;
+        }
+        case "bang": {
+          if (PREC.POSTFIX < minPrec) break loop;
+          this.i++;
+          lhs = { k: "fact", x: lhs };
+          continue loop;
+        }
+        case "unit": {
+          if (PREC.POSTFIX < minPrec) break loop;
+          this.i++;
+          lhs = { k: "unit", x: lhs, unit: tk.unit };
+          continue loop;
+        }
+        case "currency": {
+          if (PREC.POSTFIX < minPrec) break loop;
+          this.i++;
+          lhs = { k: "curr", x: lhs, code: tk.code };
+          continue loop;
+        }
+        case "scale": {
+          if (PREC.POSTFIX < minPrec) break loop;
+          this.i++;
+          lhs = { k: "scale", x: lhs, mult: tk.mult, label: "" };
+          continue loop;
+        }
+        case "op": {
+          switch (tk.op) {
+            case "pow": {
+              if (PREC.POW < minPrec) break loop;
+              const save = this.i;
+              this.i++;
+              const r = this.parseExpr(PREC.POW);
+              if (!r) { this.i = save; break loop; }
+              lhs = { k: "bin", op: "pow", l: lhs, r };
+              continue loop;
+            }
+            case "mul":
+            case "div":
+            case "mod": {
+              if (PREC.MUL < minPrec) break loop;
+              const save = this.i;
+              this.i++;
+              const r = this.parseExpr(PREC.MUL + 1);
+              if (!r) { this.i = save; break loop; }
+              lhs = { k: "bin", op: tk.op, l: lhs, r };
+              continue loop;
+            }
+            case "plus":
+            case "minus": {
+              if (PREC.ADD < minPrec) break loop;
+              const save = this.i;
+              this.i++;
+              const r = this.parseExpr(PREC.ADD + 1);
+              if (!r) { this.i = save; break loop; }
+              lhs = { k: "bin", op: tk.op, l: lhs, r };
+              continue loop;
+            }
+          }
+          break loop;
+        }
+        case "pctop": {
+          if (tk.op === "of" || tk.op === "off" || tk.op === "on") {
+            if (!(lhs.k === "pct" || lhs.k === "var" || lhs.k === "pctop")) {
+              this.i++;
+              continue loop;
+            }
+            if (PREC.MUL < minPrec) break loop;
+            const save = this.i;
+            this.i++;
+            const r = this.parseExpr(PREC.MUL + 1);
+            if (!r) { this.i = save; break loop; }
+            lhs = { k: "pctop", op: tk.op, l: lhs, r };
+            continue loop;
+          }
+          if (tk.op.startsWith("as_pct") || tk.op.endsWith("what_is")) {
+            if (PREC.CONV < minPrec) break loop;
+            const save = this.i;
+            this.i++;
+            const r = this.parseExpr(PREC.ADD);
+            if (!r) { this.i = save; break loop; }
+            lhs = { k: "pctop", op: tk.op, l: lhs, r };
+            continue loop;
+          }
+          break loop;
+        }
+        case "lparen":
+        case "const":
+        case "func":
+        case "word": {
+          if (tk.t === "word" && !this.vars.has(tk.raw)) break loop;
+          if (PREC.MUL < minPrec) break loop;
+          const save = this.i;
+          const r = this.parseExpr(PREC.MUL + 1);
+          if (!r) { this.i = save; break loop; }
+          lhs = { k: "bin", op: "mul", l: lhs, r };
+          continue loop;
+        }
+        case "bitop": {
+          if (PREC.BIT < minPrec) break loop;
+          const save = this.i;
+          this.i++;
+          const r = this.parseExpr(PREC.BIT + 1);
+          if (!r) { this.i = save; break loop; }
+          lhs = { k: "bit", op: tk.op, l: lhs, r };
+          continue loop;
+        }
+        case "conv": {
+          if (PREC.CONV < minPrec) break loop;
           const save = this.i;
           this.i++;
           const target = this.parseTarget();
-        if (!target) {
+          if (!target) { this.i = save; break loop; }
-          this.i = save;
+          lhs = { k: "conv", x: lhs, target: this.tryHistoricalDate(target) };
-          break;
+          continue loop;
         }
-        l = { k: "conv", x: l, target: this.tryHistoricalDate(target) };
-      } else if (tk?.t === "pctop" && (tk.op.startsWith("as_pct") || tk.op.endsWith("what_is"))) {
-        this.i++;
-        const r = this.parseAdd();
-        if (!r) break;
-        l = { k: "pctop", op: tk.op, l, r };
-      } else {
-        break;
-      }
-    }
-    return l;
       }
 
+      break;
+    }
+    return lhs;
+  }
   /** If the current token is `pctop(on)` + `datelit`, consume them and attach `onDate`. */
   private tryHistoricalDate(target: ConvTarget): ConvTarget {
     if (target.type !== "currency") return target;
@@ -280,122 +413,6 @@ class Parser {
     return null;
   }
 
-  private parseAdd(): Node | null {
-    let l = this.parseMul();
-    if (!l) return null;
-    for (;;) {
-      const tk = this.peek();
-      if (tk?.t === "op" && (tk.op === "plus" || tk.op === "minus")) {
-        const save = this.i;
-        this.i++;
-        const r = this.parseMul();
-        if (!r) {
-          this.i = save;
-          break;
-        }
-        l = { k: "bin", op: tk.op, l, r };
-      } else {
-        break;
-      }
-    }
-    return l;
-  }
-
-  private parseMul(): Node | null {
-    let l = this.parseUnary();
-    if (!l) return null;
-    for (;;) {
-      const tk = this.peek();
-      if (tk?.t === "op" && (tk.op === "mul" || tk.op === "div" || tk.op === "mod")) {
-        const save = this.i;
-        this.i++;
-        const r = this.parseUnary();
-        if (!r) {
-          this.i = save;
-          break;
-        }
-        l = { k: "bin", op: tk.op, l, r };
-      } else if (tk?.t === "pctop" && (tk.op === "of" || tk.op === "off" || tk.op === "on")) {
-        // of/off/on only make sense with a percent on the left ("20% of x");
-        // otherwise the word is prose noise ("5 on coffee")
-        if (!(l.k === "pct" || l.k === "var" || l.k === "pctop")) {
-          this.i++;
-          continue;
-        }
-        const save = this.i;
-        this.i++;
-        const r = this.parseUnary();
-        if (!r) {
-          this.i = save;
-          break;
-        }
-        l = { k: "pctop", op: tk.op, l, r };
-      } else if (
-        tk &&
-        (tk.t === "lparen" || tk.t === "const" || tk.t === "func" || (tk.t === "word" && this.vars.has(tk.raw)))
-      ) {
-        // implicit multiplication: 2(3+4), 2pi, 2x
-        const save = this.i;
-        const r = this.parseUnary();
-        if (!r) {
-          this.i = save;
-          break;
-        }
-        l = { k: "bin", op: "mul", l, r };
-      } else {
-        break;
-      }
-    }
-    return l;
-  }
-
-  private parseUnary(): Node | null {
-    const tk = this.peek();
-    if (tk?.t === "op" && tk.op === "minus") {
-      this.i++;
-      const x = this.parseUnary();
-      return x ? { k: "neg", x } : null;
-    }
-    if (tk?.t === "op" && tk.op === "plus") {
-      this.i++;
-      return this.parseUnary();
-    }
-    return this.parsePostfix();
-  }
-
-  private parsePostfix(): Node | null {
-    let x = this.parsePrimary();
-    if (!x) return null;
-    for (;;) {
-      const tk = this.peek();
-      if (!tk) break;
-      if (tk.t === "percent") {
-        this.i++;
-        x = { k: "pct", x };
-      } else if (tk.t === "bang") {
-        this.i++;
-        x = { k: "fact", x };
-      } else if (tk.t === "unit") {
-        this.i++;
-        x = { k: "unit", x, unit: tk.unit };
-      } else if (tk.t === "currency") {
-        this.i++;
-        x = { k: "curr", x, code: tk.code };
-      } else if (tk.t === "scale") {
-        this.i++;
-        x = { k: "scale", x, mult: tk.mult, label: "" };
-      } else if (tk.t === "op" && tk.op === "pow") {
-        this.i++;
-        const r = this.parseUnary();
-        if (!r) break;
-        x = { k: "bin", op: "pow", l: x, r };
-      } else {
-        break;
-      }
-    }
-    return x;
-  }
-
   private parsePrimary(): Node | null {
     const tk = this.peek();
     if (!tk) return null;
@@ -431,7 +448,7 @@ class Parser {
           this.i++;
           const args: Node[] = [];
           for (;;) {
-            const arg = this.parseConv();
+            const arg = this.parseExpr(PREC.CONV);
             if (arg) args.push(arg);
             const nx = this.peek();
             if (nx?.t === "semicolon") {
@@ -452,12 +469,12 @@ class Parser {
         // `sqrt 16` / `square root of 16` — the "of" is decorative
         const nx = this.peek();
         if (nx?.t === "pctop" && nx.op === "of") this.i++;
-        const arg = this.parseUnary();
+        const arg = this.parseExpr(PREC.UNARY);
         return arg ? { k: "call", name, args: [arg] } : null;
       }
       case "lparen": {
         this.i++;
-        const inner = this.parseConv();
+        const inner = this.parseExpr(PREC.CONV);
         if (this.peek()?.t === "rparen") this.i++;
         return inner;
       }

src/engine/registry.test.ts

@@ -0,0 +1,162 @@
+import { describe, it, expect, beforeEach } from "vitest";
+import { buildRegistry, Registry } from "./registry";
+import { lexLine } from "./lexer";
+import { Decimal } from "./types";
+
+describe("registry", () => {
+  let reg: Registry;
+
+  beforeEach(() => {
+    reg = buildRegistry();
+  });
+
+  describe("buildRegistry", () => {
+    it("initializes a valid Registry instance with core vocabulary", () => {
+      // Check core words
+      const plusPayload = reg.match(lexLine("plus"), ["plus"], 0);
+      expect(plusPayload).not.toBeNull();
+      expect(plusPayload?.payload.t).toBe("op");
+      if (plusPayload?.payload.t === "op") expect(plusPayload.payload.op).toBe("plus");
+
+      const piPayload = reg.match(lexLine("pi"), ["pi"], 0);
+      expect(piPayload).not.toBeNull();
+      expect(piPayload?.payload.t).toBe("const");
+      if (piPayload?.payload.t === "const") expect(piPayload.payload.name).toBe("pi");
+    });
+
+    it("registers built-in functions", () => {
+      expect(reg.isFunc("sin")).toBe(true);
+      expect(reg.isFunc("sqrt")).toBe(true);
+      expect(reg.isFunc("random")).toBe(true);
+      expect(reg.isFunc("unknownFunc")).toBe(false);
+
+      const sinPayload = reg.match(lexLine("sin"), ["sin"], 0);
+      expect(sinPayload).not.toBeNull();
+      expect(sinPayload?.payload.t).toBe("func");
+    });
+
+    it("registers common units", () => {
+      // "meter"
+      const meterPayload = reg.match(lexLine("meter"), ["meter"], 0);
+      expect(meterPayload).not.toBeNull();
+      expect(meterPayload?.payload.t).toBe("unit");
+
+      // "kg" (strict/lenient)
+      const kgPayload = reg.match(lexLine("kg"), ["kg"], 0);
+      expect(kgPayload).not.toBeNull();
+      expect(kgPayload?.payload.t).toBe("unit");
+
+      // "USD" (strict/lenient currency)
+      const usdPayload = reg.match(lexLine("USD"), ["usd"], 0);
+      expect(usdPayload).not.toBeNull();
+      expect(usdPayload?.payload.t).toBe("currency");
+    });
+  });
+
+  describe("match", () => {
+    it("matches single-word phrases", () => {
+      const match = reg.match(lexLine("usd"), ["usd"], 0);
+      expect(match).not.toBeNull();
+      expect(match?.length).toBe(1);
+    });
+
+    it("matches multi-word phrases", () => {
+      const match = reg.match(lexLine("square meter"), ["square", "meter"], 0);
+      expect(match).not.toBeNull();
+      expect(match?.length).toBe(2);
+      expect(match?.payload.t).toBe("unit");
+    });
+
+    it("respects case-sensitivity", () => {
+      // "m" (milli) vs "M" (mega)
+      const mMatch = reg.match(lexLine("mm"), ["mm"], 0);
+      const mPayload = mMatch?.payload;
+      expect(mPayload?.t).toBe("unit");
+
+      const MMatch = reg.match(lexLine("Mm"), ["mm"], 0);
+      const MPayload = MMatch?.payload;
+      expect(MPayload?.t).toBe("unit");
+
+      if (mPayload?.t === "unit" && MPayload?.t === "unit") {
+        expect(mPayload.unit.id).not.toBe(MPayload.unit.id);
+        expect(mPayload.unit.id).toBe("milli:meter");
+        expect(MPayload.unit.id).toBe("mega:meter");
+      }
+    });
+
+    it("respects mustTouch flag", () => {
+      // "log2" vs "log 2"
+      const lex2 = lexLine("log2");
+      const log2Match = reg.match(lex2, lex2.map(l => l.raw), 0);
+      expect(log2Match).not.toBeNull();
+      expect(log2Match?.payload.t).toBe("func");
+      if (log2Match?.payload.t === "func") expect(log2Match.payload.name).toBe("log2");
+
+      const lexSpace2 = lexLine("log 2");
+      const logSpace2Match = reg.match(lexSpace2, lexSpace2.map(l => l.raw), 0);
+      // "log 2" should match "log", length 1, not "log2"
+      expect(logSpace2Match).not.toBeNull();
+      expect(logSpace2Match?.length).toBe(1);
+      if (logSpace2Match?.payload.t === "func") expect(logSpace2Match.payload.name).toBe("log");
+    });
+
+    it("returns null for no match", () => {
+      const match = reg.match(lexLine("unknownword"), ["unknownword"], 0);
+      expect(match).toBeNull();
+    });
+  });
+
+  describe("currency and rates", () => {
+    it("sets and updates conversion rates", () => {
+      reg.setRates({ "EUR": 0.9, "GBP": "0.8" });
+      expect(reg.rates.get("EUR")?.toNumber()).toBe(0.9);
+      expect(reg.rates.get("GBP")?.toNumber()).toBe(0.8);
+      // USD is implicitly set to 1
+      expect(reg.rates.get("USD")?.toNumber()).toBe(1);
+    });
+
+    it("ignores negative rates", () => {
+      reg.setRates({ "EUR": 0.9, "INVALID": -1 });
+      expect(reg.rates.get("EUR")?.toNumber()).toBe(0.9);
+      expect(reg.rates.has("INVALID")).toBe(false);
+    });
+
+    it("creates currency unit from rate", () => {
+      const unit = reg.makeCurrencyUnitFromRate("EUR", new Decimal(0.9));
+      expect(unit.id).toBe("EUR");
+      expect(unit.dimension).toBe("currency");
+      // 1 / 0.9 = 1.111...
+      expect(unit.ratio.toNumber()).toBeCloseTo(1.1111, 4);
+    });
+
+    it("makes currency unit if rate exists", () => {
+      reg.setRates({ "EUR": 0.9 });
+      const unit = reg.makeCurrencyUnit("EUR");
+      expect(unit).not.toBeNull();
+      expect(unit?.id).toBe("EUR");
+
+      const noUnit = reg.makeCurrencyUnit("JPY");
+      expect(noUnit).toBeNull();
+    });
+  });
+
+  describe("completions", () => {
+    it("populates completions with expected categories", () => {
+      expect(reg.completions.length).toBeGreaterThan(0);
+
+      const types = new Set(reg.completions.map(c => c.type));
+      expect(types.has("unit")).toBe(true);
+      expect(types.has("currency")).toBe(true);
+      expect(types.has("function")).toBe(true);
+      expect(types.has("keyword")).toBe(true);
+    });
+
+    it("contains specific known completions", () => {
+      const labels = reg.completions.map(c => c.label);
+      expect(labels).toContain("USD");
+      expect(labels).toContain("meter");
+      expect(labels).toContain("sin");
+      expect(labels).toContain("sum");
+    });
+  });
+});

src/engine/registry.ts

@@ -8,6 +8,7 @@ import * as vocab from "./vocab";
 import { UNIT_DATA, SI_PREFIXES, DATA_SI_PREFIXES, IEC_PREFIXES, SCALE_DATA } from "./unitdata";
 import { EXTRA_UNITS, CRYPTO } from "./extraunits";
 
+/** Operators for percentage calculations. */
 export type PctOp =
   | "of" | "off" | "on"
   | "as_pct_of" | "as_pct_off" | "as_pct_on"
@@ -177,29 +178,29 @@ function registerCoreVocab(reg: Registry): void {
     ["minus", { t: "op", op: "minus" }],
     ["multiply", { t: "op", op: "mul" }],
     ["divide", { t: "op", op: "div" }],
+    ["conversion", { t: "conv" }],
+    ["assignment", { t: "assign" }],
+    ["sum", { t: "agg", name: "sum" }],
+    ["avg", { t: "agg", name: "avg" }],
+    ["prev", { t: "agg", name: "prev" }],
+    ["count", { t: "agg", name: "count" }],
+    ["min", { t: "agg", name: "min" }],
+    ["max", { t: "agg", name: "max" }],
+    ["product", { t: "agg", name: "product" }],
+    ["chart", { t: "agg", name: "chart" }],
+    ["sqrt", { t: "func", name: "sqrt" }],
+    ["cbrt", { t: "func", name: "cbrt" }],
+    ["abs", { t: "func", name: "abs" }],
+    ["ln", { t: "func", name: "ln" }],
+    ["log", { t: "func", name: "log" }],
+    ["round", { t: "func", name: "round" }],
+    ["random", { t: "func", name: "random" }],
+    ["until", { t: "func", name: "until" }],
+    ["since", { t: "func", name: "since" }],
   ];
   for (const [key, payload] of ops) {
     for (const v of vocab.variants("Operations", `${key}.variants`)) reg.addPhrase(v, payload, { caseSensitive: false });
   }
-  for (const v of vocab.variants("Operations", "conversion.variants")) reg.addPhrase(v, { t: "conv" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "assignment.variants")) reg.addPhrase(v, { t: "assign" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "sum.variants")) reg.addPhrase(v, { t: "agg", name: "sum" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "avg.variants")) reg.addPhrase(v, { t: "agg", name: "avg" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "prev.variants")) reg.addPhrase(v, { t: "agg", name: "prev" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "count.variants")) reg.addPhrase(v, { t: "agg", name: "count" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "min.variants")) reg.addPhrase(v, { t: "agg", name: "min" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "max.variants")) reg.addPhrase(v, { t: "agg", name: "max" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "product.variants")) reg.addPhrase(v, { t: "agg", name: "product" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "chart.variants")) reg.addPhrase(v, { t: "agg", name: "chart" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "sqrt.variants")) reg.addPhrase(v, { t: "func", name: "sqrt" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "cbrt.variants")) reg.addPhrase(v, { t: "func", name: "cbrt" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "abs.variants")) reg.addPhrase(v, { t: "func", name: "abs" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "ln.variants")) reg.addPhrase(v, { t: "func", name: "ln" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "log.variants")) reg.addPhrase(v, { t: "func", name: "log" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "round.variants")) reg.addPhrase(v, { t: "func", name: "round" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "random.variants")) reg.addPhrase(v, { t: "func", name: "random" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "until.variants")) reg.addPhrase(v, { t: "func", name: "until" }, { caseSensitive: false });
-  for (const v of vocab.variants("Operations", "since.variants")) reg.addPhrase(v, { t: "func", name: "since" }, { caseSensitive: false });
   reg.addPhrase("mod", { t: "op", op: "mod" }, { caseSensitive: false });
   reg.addPhrase("modulo", { t: "op", op: "mod" }, { caseSensitive: false });
 

src/engine/tokenizer.test.ts

@@ -0,0 +1,92 @@
+import { describe, it, expect, beforeAll } from "vitest";
+import { tokenize } from "./tokenizer";
+import { buildRegistry, Registry } from "./registry";
+
+describe("tokenizer", () => {
+  let reg: Registry;
+
+  beforeAll(() => {
+    reg = buildRegistry();
+  });
+
+  it("tokenizes numbers and basic operators", () => {
+    const tokens = tokenize("1 + 2 * 3.5 - 4 / 2 ^ 3", reg);
+    expect(tokens.map(t => t.t)).toEqual([
+      "num", "op", "num", "op", "num", "op", "num", "op", "num", "op", "num"
+    ]);
+  });
+
+  it("handles dates", () => {
+    const tokens = tokenize("2024-01-01 + 5 days", reg);
+    expect(tokens[0].t).toBe("datelit");
+    expect(tokens.map(t => t.t)).toEqual(["datelit", "op", "num", "unit"]);
+  });
+
+  it("handles xrefs", () => {
+    const tokens = tokenize("@Sheet.key", reg);
+    expect(tokens[0].t).toBe("xref");
+    if (tokens[0].t === "xref") {
+      expect(tokens[0].sheet).toBe("Sheet");
+      expect(tokens[0].key).toBe("key");
+    }
+  });
+
+  it("handles bitwise operators", () => {
+    const tokens = tokenize("5 << 1 >> 2 & 3 | 4", reg);
+    const typesAndOps = tokens.map(t => t.t === "bitop" ? `bitop:${t.op}` : t.t);
+    expect(typesAndOps).toEqual([
+      "num", "bitop:shl", "num", "bitop:shr", "num", "bitop:band", "num", "bitop:bor", "num"
+    ]);
+  });
+
+  it("handles registry matches like units and currencies", () => {
+    const tokens = tokenize("100 USD to EUR", reg);
+    const types = tokens.map(t => t.t);
+    expect(types).toEqual(["num", "currency", "conv", "currency"]);
+  });
+
+  it("disambiguates 'in' as inches", () => {
+    const tokens = tokenize("5 ft 4 in in cm", reg);
+    expect(tokens.map(t => t.t)).toEqual(["num", "unit", "num", "unit", "conv", "unit"]);
+    if (tokens[3].t === "unit") {
+      expect(tokens[3].unit.id).toBe("inch");
+    }
+  });
+
+  it("does not disambiguate 'in' when it is not inches", () => {
+    const tokens = tokenize("in cm", reg);
+    expect(tokens.map(t => t.t)).toEqual(["conv", "unit"]);
+  });
+
+  it("handles other registry constructs (funcs, aggs, etc)", () => {
+    const tokens = tokenize("sum(1, 2) + sin(pi) %", reg);
+    expect(tokens.map(t => t.t)).toEqual([
+      "agg", "lparen", "num", "junk", "num", "rparen", "op", "func", "lparen", "const", "rparen", "percent"
+    ]);
+  });
+
+  it("handles scale and repr", () => {
+    const tokens = tokenize("1M in hex", reg);
+    expect(tokens.map(t => t.t)).toEqual(["num", "scale", "conv", "repr"]);
+  });
+
+  it("handles pctop and date words", () => {
+    const tokens = tokenize("5% of 100 today", reg);
+    expect(tokens.map(t => t.t)).toEqual(["num", "percent", "pctop", "num", "date"]);
+  });
+
+  it("handles bang, semicolon, unknown", () => {
+    const tokens = tokenize("! ; ?", reg);
+    expect(tokens.map(t => t.t)).toEqual(["bang", "semicolon", "unknown"]);
+  });
+
+  it("handles special tokens", () => {
+    const tokens = tokenize("unix date", reg);
+    expect(tokens.map(t => t.t)).toEqual(["special", "special"]);
+  });
+
+  it("handles assign", () => {
+    const tokens = tokenize("x = 5", reg);
+    expect(tokens.map(t => t.t)).toEqual(["word", "assign", "num"]);
+  });
+});

src/engine/tokenizer.ts

@@ -115,7 +115,7 @@ export function tokenize(line: string, reg: Registry, dateOrder: DateOrder = "dm
     tokens.push({ t: "word", raw: lx.raw, ...span });
     i++;
   }
-  return disambiguateIn(tokens, reg, line);
+  return disambiguateMinAgg(disambiguateIn(tokens, reg, line), reg, line);
 }
 
 /**
@@ -138,3 +138,21 @@ function disambiguateIn(tokens: Token[], reg: Registry, line: string): Token[] {
     return tk;
   });
 }
+
+/**
+ * "5 min": the "min" aggregate keyword (registered first, so it wins the
+ * phrase in the registry) collides with the minute unit's "min"/"мин"
+ * abbreviation. Right after a number it can only mean minutes — the
+ * standalone `min` aggregate line has no preceding number to collide with.
+ */
+function disambiguateMinAgg(tokens: Token[], reg: Registry, line: string): Token[] {
+  const minute = reg.unitsById.get("minute");
+  if (!minute) return tokens;
+  return tokens.map((tk, i) => {
+    if (tk.t !== "agg" || tk.name !== "min") return tk;
+    const raw = line.slice(tk.start, tk.end).toLowerCase();
+    if (raw !== "min" && raw !== "мин") return tk;
+    if (tokens[i - 1]?.t !== "num") return tk;
+    return { t: "unit", unit: minute, start: tk.start, end: tk.end } as Token;
+  });
+}

src/engine/types.test.ts

@@ -0,0 +1,41 @@
+import { describe, it, expect } from "vitest";
+import { qty, pct, Decimal } from "./types";
+
+describe("types", () => {
+  describe("qty", () => {
+    it("creates a quantity with default arguments", () => {
+      const result = qty(42);
+      expect(result.kind).toBe("quantity");
+      expect(result.value).toBeInstanceOf(Decimal);
+      expect(result.value.toNumber()).toBe(42);
+      expect(result.unit).toBeNull();
+      expect(result.repr).toBe("decimal");
+    });
+
+    it("creates a quantity with all arguments provided", () => {
+      const mockUnit = { id: "meter", dimension: "length", ratio: new Decimal(1), format: "m" } as any;
+      const result = qty("3.14", mockUnit, "hex");
+      expect(result.kind).toBe("quantity");
+      expect(result.value).toBeInstanceOf(Decimal);
+      expect(result.value.toString()).toBe("3.14");
+      expect(result.unit).toBe(mockUnit);
+      expect(result.repr).toBe("hex");
+    });
+  });
+
+  describe("pct", () => {
+    it("creates a percent value from number", () => {
+      const result = pct(25);
+      expect(result.kind).toBe("percent");
+      expect(result.value).toBeInstanceOf(Decimal);
+      expect(result.value.toNumber()).toBe(25);
+    });
+
+    it("creates a percent value from string", () => {
+      const result = pct("12.5");
+      expect(result.kind).toBe("percent");
+      expect(result.value).toBeInstanceOf(Decimal);
+      expect(result.value.toString()).toBe("12.5");
+    });
+  });
+});

src/engine/types.ts

@@ -4,6 +4,11 @@ Decimal.set({ precision: 40, toExpNeg: -9, toExpPos: 21 });
 
 export { Decimal };
 
+/** Shared here (not in evaluator.ts) so unitdata.ts can use it too without a cycle. */
+export const PI = new Decimal("3.14159265358979323846264338327950288419716939937510");
+export const DEC_ZERO = new Decimal(0);
+export const DEC_ONE = new Decimal(1);
+
 export type Dimension =
   | "scalar"
   | "length"

src/engine/unitdata.ts

@@ -1,7 +1,7 @@
 // Conversion ratios. Base units per dimension: length=meter, area=m²,
 // volume=m³, weight=gram, time=second, angle=radian, data=bit,
 // temperature=kelvin (ratio+offset).
-import { Decimal, Dimension } from "./types";
+import { Decimal, Dimension, PI } from "./types";
 
 export interface UnitData {
   id: string;
@@ -79,7 +79,7 @@ export const UNIT_DATA: UnitData[] = [
 
   // Angle (base: radian)
   { id: "radian", category: "Angle", dimension: "angle", ratio: "1" },
-  { id: "degree", category: "Angle", dimension: "angle", ratio: String(Math.PI / 180) },
+  { id: "degree", category: "Angle", dimension: "angle", ratio: PI.div(180).toString() },
 
   // Data (base: bit)
   { id: "bit", category: "Data", dimension: "data", ratio: "1", prefixes: "data" },

src/engine/vocab-data.ts

@@ -169,11 +169,13 @@ export const EN: VocabLocale = {
     "KES.format": "%@ KSh",
     "KES.variants": "Kenyan Shillings,Kenyan Shilling,KSh",
     "KGS.format": "%@ sом",
-    "KGS.variants": "Kyrgyzstani Soms,Kyrgyzstani Som,Soms,Som,sом",
+    // bare "Som"/"Soms" dropped — UZS (larger economy) owns it; say "Kyrgyzstani Som" for KGS
+    "KGS.variants": "Kyrgyzstani Soms,Kyrgyzstani Som,sом",
     "KHR.format": "%@ R.",
     "KHR.variants": "Cambodian Riel,Riel,៛,Cambodian Riels,Riels",
     "KMF.format": "%@ FC",
-    "KMF.variants": "Comorian Francs,Comorian Franc,FC",
+    // bare "FC" dropped — CDF (Congolese franc, registered first) owns it; say "Comorian Franc" for KMF
+    "KMF.variants": "Comorian Francs,Comorian Franc",
     "KPW.format": "￦ %@",
     "KPW.variants": "North Korean won",
     "KRW.format": "￦ %@",
@@ -221,7 +223,8 @@ export const EN: VocabLocale = {
     "MVR.format": "Rf %@",
     "MVR.variants": "Maldivian Rufiyaa,Rufiyaa,Rf",
     "MWK.format": "%@ MK",
-    "MWK.variants": "Malawian Kwacha,Kwacha",
+    // bare "Kwacha" dropped — ZMW (larger economy) owns it; say "Malawian Kwacha" for MWK
+    "MWK.variants": "Malawian Kwacha",
     "MXN.format": "$ %@",
     "MXN.variants": "Mexican Peso,Mexican Pesos",
     "MYR.format": "RM %@",
@@ -301,7 +304,8 @@ export const EN: VocabLocale = {
     "TJS.format": "%@ TJS",
     "TJS.variants": "Tajikistani Somoni,Somoni",
     "TMT.format": "%@ TMT",
-    "TMT.variants": "Turkmenistan Manat,Manat",
+    // bare "Manat" dropped — AZN (registered first) owns it; say "Turkmenistan Manat" for TMT
+    "TMT.variants": "Turkmenistan Manat",
     "TND.format": "%@ TD",
     "TND.variants": "Tunisian Dinar,Tunisian Dinars,د.ت,TD",
     "TOP.format": "T$ %@",
@@ -733,7 +737,8 @@ export const RU: VocabLocale = {
     "MUR.variants": "Маврикийская рупия,Маврикийских рупий,Маврикийских рупиях",
     "MVR.format": "%@ Rf",
     "MVR.variants": "Мальдивская руфия,Руфия,Руфий,Руфиях",
-    "MWK.variants": "Малавийская квача,Малавийских квач,Малавийских квачах,Квача,Квачах",
+    // bare "Квача"/"Квачах" dropped — ZMW (larger economy) owns them; the fuller phrases stay unambiguous
+    "MWK.variants": "Малавийская квача,Малавийских квач,Малавийских квачах",
     "MXN.format": "%@ $",
     "MXN.variants": "Мексиканских песо,Мексиканское песо",
     "MYR.format": "%@ RM",
@@ -793,7 +798,8 @@ export const RU: VocabLocale = {
     "THB.variants": "Тайский бат,Бат,Батов,Батах",
     "TJS.format": "%@ смн.",
     "TJS.variants": "Таджикский сомони,Сомони",
-    "TMT.variants": "Туркменский манат,Новый туркменский манат,Манат,Манатов,Туркменских манатов,Маната,Туркменских маната",
+    // bare "Манат" dropped — AZN owns it; the fuller phrases below stay unambiguous
+    "TMT.variants": "Туркменский манат,Новый туркменский манат,Манатов,Туркменских манатов,Маната,Туркменских маната",
     "TND.variants": "Тунисские Динары,Тунисский Динар,Тунисских Динаров,Тунисских Динарах",
     "TOP.format": "%@ T$",
     "TOP.variants": "Тонганская паанга,Паанга,Паангах",

src/engine/vocab.test.ts

@@ -0,0 +1,102 @@
+import { describe, it, expect, vi } from "vitest";
+
+vi.mock("./vocab-data", () => ({
+  EN: {
+    "TestCategory": {
+      "test_key.variants": "a, b, c ,a,  ",
+      "test_key.format": "en_fmt",
+      "test_key.suffix1": "val1",
+      "test_key2.variants": "x,y",
+      "test_key2.suffix1": "val2",
+      "same.key": "duplicate",
+    }
+  },
+  RU: {
+    "TestCategory": {
+      "test_key.variants": "d, b , e",
+      "test_key.format": "ru_fmt",
+      "test_key3.variants": "z",
+      "test_key3.suffix2": "val3",
+      "same.key": "duplicate",
+    }
+  }
+}));
+
+import { variants, entry, entryEn, entriesAll, idsOf, idsWithSuffix } from "./vocab";
+
+describe("vocab", () => {
+  describe("variants", () => {
+    it("returns comma-split, trimmed, and deduped variants across locales", () => {
+      // EN has "a", "b", "c", "a", "" (empty string trimmed out)
+      // RU has "d", "b", "e"
+      const res = variants("TestCategory", "test_key.variants");
+      expect(res).toEqual(["a", "b", "c", "d", "e"]);
+    });
+
+    it("returns empty array for unknown category or key", () => {
+      expect(variants("UnknownCategory", "test_key.variants")).toEqual([]);
+      expect(variants("TestCategory", "unknown_key.variants")).toEqual([]);
+    });
+  });
+
+  describe("entry", () => {
+    it("returns the first locale's value", () => {
+      expect(entry("TestCategory", "test_key.format")).toBe("en_fmt");
+    });
+
+    it("returns undefined for unknown category or key", () => {
+      expect(entry("UnknownCategory", "test_key.format")).toBeUndefined();
+      expect(entry("TestCategory", "unknown_key")).toBeUndefined();
+    });
+  });
+
+  describe("entryEn", () => {
+    it("returns only the English value", () => {
+      expect(entryEn("TestCategory", "test_key.format")).toBe("en_fmt");
+    });
+
+    it("returns undefined if only in RU", () => {
+      expect(entryEn("TestCategory", "test_key3.variants")).toBeUndefined();
+    });
+  });
+
+  describe("entriesAll", () => {
+    it("returns all unique values across locales", () => {
+      expect(entriesAll("TestCategory", "test_key.format")).toEqual(["en_fmt", "ru_fmt"]);
+    });
+
+    it("deduplicates values if they are the same in multiple locales", () => {
+      expect(entriesAll("TestCategory", "same.key")).toEqual(["duplicate"]);
+    });
+
+    it("returns empty array for unknown category or key", () => {
+      expect(entriesAll("UnknownCategory", "test_key.format")).toEqual([]);
+    });
+  });
+
+  describe("idsOf", () => {
+    it("returns all base keys ending in .variants across locales", () => {
+      const res = idsOf("TestCategory");
+      expect(res.sort()).toEqual(["test_key", "test_key2", "test_key3"].sort());
+    });
+
+    it("returns empty array for unknown category", () => {
+      expect(idsOf("UnknownCategory")).toEqual([]);
+    });
+  });
+
+  describe("idsWithSuffix", () => {
+    it("returns all keys ending with the given suffix across locales", () => {
+      const res1 = idsWithSuffix("TestCategory", ".suffix1");
+      expect(res1.sort()).toEqual(["test_key", "test_key2"].sort());
+
+      const res2 = idsWithSuffix("TestCategory", ".suffix2");
+      expect(res2).toEqual(["test_key3"]);
+    });
+
+    it("returns empty array for unknown category or suffix", () => {
+      expect(idsWithSuffix("UnknownCategory", ".suffix1")).toEqual([]);
+      expect(idsWithSuffix("TestCategory", ".unknown_suffix")).toEqual([]);
+    });
+  });
+});

src/extensions.test.ts

@@ -0,0 +1,207 @@
+import { logger } from "./logger";
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
+import { makeApi, runExtensions } from "./extensions";
+import { SumEngine } from "./engine";
+
+describe("extensions", () => {
+  let mockEngine: any;
+
+  beforeEach(() => {
+    mockEngine = {
+      setVariable: vi.fn(),
+      addUnit: vi.fn(),
+      addFunction: vi.fn(),
+    };
+  });
+
+  describe("makeApi", () => {
+    it("delegates setVariable to engine", () => {
+      const api = makeApi(mockEngine as SumEngine);
+      api.setVariable("myVar", 42);
+      expect(mockEngine.setVariable).toHaveBeenCalledWith("myVar", 42);
+    });
+
+    it("delegates addUnit to engine", () => {
+      const api = makeApi(mockEngine as SumEngine);
+      const spec = { id: "testUnit", phrases: "tests", baseUnitId: "USD", ratio: 1 };
+      api.addUnit(spec);
+      expect(mockEngine.addUnit).toHaveBeenCalledWith(spec);
+    });
+
+    it("delegates addFunction to engine", () => {
+      const api = makeApi(mockEngine as SumEngine);
+      const spec = { id: "testFunc", phrases: "test" };
+      const fn = () => 42;
+      api.addFunction(spec, fn);
+      expect(mockEngine.addFunction).toHaveBeenCalledWith(spec, fn);
+    });
+  });
+
+  describe("runExtensions", () => {
+    let consoleErrorSpy: any;
+    let consoleWarnSpy: any;
+
+    beforeEach(() => {
+      consoleErrorSpy = vi.spyOn(logger, "error").mockImplementation(() => {});
+      consoleWarnSpy = vi.spyOn(logger, "warn").mockImplementation(() => {});
+    });
+
+    afterEach(() => {
+      consoleErrorSpy.mockRestore();
+      consoleWarnSpy.mockRestore();
+      vi.resetModules();
+      vi.doUnmock("quickjs-emscripten-core");
+    });
+
+    it("runs scripts successfully using numi api", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        { name: "script1", code: "numi.setVariable('var1', 10);" },
+        { name: "script2", code: "numi.addUnit({ id: 'unit1', phrases: 'u', baseUnitId: 'USD', ratio: 1 });" },
+      ]);
+
+      expect(mockEngine.setVariable).toHaveBeenCalledWith("var1", 10);
+      expect(mockEngine.addUnit).toHaveBeenCalledWith({
+        id: "unit1",
+        phrases: "u",
+        baseUnitId: "USD",
+        ratio: 1,
+      });
+      expect(consoleErrorSpy).not.toHaveBeenCalled();
+    });
+
+    it("swallows errors and logs to console.error", async () => {
+      await runExtensions(mockEngine as SumEngine, [{ name: "script1", code: "throw new Error('test error');" }]);
+
+      expect(consoleErrorSpy).toHaveBeenCalledWith("extension script1 failed:", expect.any(Error));
+      expect(consoleErrorSpy.mock.calls[0][1].message).toContain("test error");
+    });
+
+    it("continues running other scripts if one fails", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        { name: "script1", code: "numi.setVariable('var1', 10);" },
+        { name: "script2", code: "throw new Error('boom');" },
+        { name: "script3", code: "numi.setVariable('var3', 30);" },
+      ]);
+
+      expect(mockEngine.setVariable).toHaveBeenCalledWith("var1", 10);
+      expect(mockEngine.setVariable).toHaveBeenCalledWith("var3", 30);
+      expect(consoleErrorSpy).toHaveBeenCalledTimes(1);
+    });
+
+    it("passes unit-carrying values through setVariable", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        { name: "s", code: "numi.setVariable('rent', { double: 1200, unitId: 'USD' });" },
+      ]);
+
+      expect(mockEngine.setVariable).toHaveBeenCalledWith("rent", { double: 1200, unitId: "USD" });
+    });
+
+    it("rejects malformed api arguments as a script error", async () => {
+      await runExtensions(mockEngine as SumEngine, [{ name: "bad", code: "numi.setVariable('x', 'nope');" }]);
+
+      expect(mockEngine.setVariable).not.toHaveBeenCalled();
+      expect(consoleErrorSpy.mock.calls[0][1].message).toContain("numi.setVariable");
+    });
+
+    it("registers a function callable with one array of values", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        {
+          name: "hyp",
+          code: "numi.addFunction({ id: 'hyp', phrases: 'hyp' }, function (values) { return { double: Math.hypot(values[0].double, values[1].double) }; });",
+        },
+      ]);
+
+      expect(mockEngine.addFunction).toHaveBeenCalledWith({ id: "hyp", phrases: "hyp" }, expect.any(Function));
+      const fn = mockEngine.addFunction.mock.calls[0][1];
+      expect(fn([{ double: 3 }, { double: 4 }])).toEqual({ double: 5 });
+      expect(fn([{ double: 6 }, { double: 8 }])).toEqual({ double: 10 });
+    });
+
+    it("marshals unitId into the sandbox and back out", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        {
+          name: "echo",
+          code: "numi.addFunction({ id: 'echo', phrases: 'echo' }, function (v) { return { double: v[0].double * 2, unitId: v[0].unitId }; });",
+        },
+      ]);
+
+      const fn = mockEngine.addFunction.mock.calls[0][1];
+      expect(fn([{ double: 5, unitId: "meter" }])).toEqual({ double: 10, unitId: "meter" });
+    });
+
+    it("has no host globals inside the sandbox", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        { name: "probe", code: "if (typeof window !== 'undefined' || typeof fetch !== 'undefined' || typeof console !== 'undefined') throw new Error('leak');" },
+      ]);
+
+      expect(consoleErrorSpy).not.toHaveBeenCalled();
+    });
+
+    it("interrupts an infinite loop at load time", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        { name: "spin", code: "while (true) {}" },
+        { name: "after", code: "numi.setVariable('ok', 1);" },
+      ]);
+
+      expect(consoleErrorSpy).toHaveBeenCalledTimes(1);
+      expect(consoleErrorSpy.mock.calls[0][0]).toBe("extension spin failed:");
+      // the runtime survives the interrupt and keeps loading scripts
+      expect(mockEngine.setVariable).toHaveBeenCalledWith("ok", 1);
+    });
+
+    it("interrupts a hung function on every call, not just the first", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        {
+          name: "spin",
+          code: "numi.addFunction({ id: 'spin', phrases: 'spin' }, function () { while (true) {} });",
+        },
+        {
+          name: "good",
+          code: "numi.addFunction({ id: 'good', phrases: 'good' }, function (v) { return v[0].double + 1; });",
+        },
+      ]);
+
+      const spin = mockEngine.addFunction.mock.calls[0][1];
+      const good = mockEngine.addFunction.mock.calls[1][1];
+
+      expect(() => spin([])).toThrow(/spin/);
+      // deadline is re-armed per call: a second call still times out rather than
+      // failing instantly, and an unrelated function still works afterwards
+      expect(() => spin([])).toThrow(/spin/);
+      expect(good([{ double: 1 }])).toBe(2);
+    });
+
+    it("surfaces a bad return value as a function error", async () => {
+      await runExtensions(mockEngine as SumEngine, [
+        { name: "bad", code: "numi.addFunction({ id: 'bad', phrases: 'bad' }, function () { return 'nope'; });" },
+      ]);
+
+      const fn = mockEngine.addFunction.mock.calls[0][1];
+      expect(() => fn([])).toThrow(/bad/);
+    });
+
+    it("skips extensions when the sandbox fails to load", async () => {
+      vi.resetModules();
+      vi.doMock("quickjs-emscripten-core", () => ({
+        newQuickJSWASMModuleFromVariant: () => Promise.reject(new Error("no WebAssembly")),
+      }));
+      const { runExtensions: run } = await import("./extensions");
+      const { logger } = await import("./logger");
+      consoleWarnSpy = vi.spyOn(logger, "warn").mockImplementation(() => {});
+
+      await run(mockEngine as SumEngine, [{ name: "s", code: "numi.setVariable('x', 1);" }]);
+
+      expect(mockEngine.setVariable).not.toHaveBeenCalled();
+      expect(consoleWarnSpy).toHaveBeenCalledWith(
+        "extensions disabled: QuickJS sandbox unavailable:",
+        expect.any(Error),
+      );
+    });
+
+    it("does not load the sandbox when there are no scripts", async () => {
+      await runExtensions(mockEngine as SumEngine, []);
+      expect(consoleWarnSpy).not.toHaveBeenCalled();
+      expect(consoleErrorSpy).not.toHaveBeenCalled();
+    });
+  });
+});

src/extensions.ts

@@ -1,11 +1,21 @@
-// JS extensions runtime: numi.setVariable,
+import { logger } from "./logger";
-// numi.addUnit, numi.addFunction. Scripts share the engine's JS runtime.
+// JS extensions runtime: numi.setVariable, numi.addUnit, numi.addFunction.
+// Scripts run inside a QuickJS WASM sandbox — no DOM, no Tauri IPC, no host globals.
+import {
+  newQuickJSWASMModuleFromVariant,
+  QuickJSContext,
+  QuickJSHandle,
+} from "quickjs-emscripten-core";
+import releaseSyncVariant from "@jitl/quickjs-singlefile-browser-release-sync";
 import { SumEngine, ExtensionUnitSpec, ExtensionValue } from "./engine";
 
-export interface ExtensionApi {
+interface ExtensionApi {
   setVariable(name: string, value: number | ExtensionValue): void;
   addUnit(spec: ExtensionUnitSpec): void;
-  addFunction(spec: { id: string; phrases: string }, fn: (values: ExtensionValue[]) => ExtensionValue | number): void;
+  addFunction(
+    spec: { id: string; phrases: string },
+    fn: (values: ExtensionValue[]) => ExtensionValue | number,
+  ): void;
 }
 
 export function makeApi(engine: SumEngine): ExtensionApi {
@@ -16,14 +26,209 @@ export function makeApi(engine: SumEngine): ExtensionApi {
   };
 }
 
-export function runExtensions(engine: SumEngine, scripts: { name: string; code: string }[]): void {
+// 32 MB is orders of magnitude more than a sheet helper needs, and small enough
-  const numi = makeApi(engine);
+// that a runaway allocation fails inside the sandbox instead of the host heap.
+const MEMORY_LIMIT = 32 * 1024 * 1024;
+// 512 KB — unbounded recursion hits this and throws in the sandbox, never on the JS stack.
+const STACK_SIZE = 512 * 1024;
+// One-off cost at startup, so it can be generous.
+const LOAD_TIMEOUT_MS = 1000;
+// Registered functions are called synchronously from evaluateDocument, i.e. on
+// every keystroke for every line that uses them — this budget must stay small.
+const CALL_TIMEOUT_MS = 50;
+
+const now = () =>
+  typeof performance !== "undefined" ? performance.now() : Date.now();
+
+function toExtValue(v: unknown, what: string): ExtensionValue | number {
+  if (typeof v === "number" && Number.isFinite(v)) return v;
+  if (v && typeof v === "object") {
+    const o = v as { double?: unknown; unitId?: unknown };
+    if (typeof o.double === "number" && Number.isFinite(o.double)) {
+      return typeof o.unitId === "string"
+        ? { double: o.double, unitId: o.unitId }
+        : { double: o.double };
+    }
+  }
+  throw new Error(`${what}: expected a number or { double, unitId? }`);
+}
+
+function message(e: unknown): string {
+  if (e instanceof Error) return e.message;
+  if (
+    e &&
+    typeof e === "object" &&
+    typeof (e as { message?: unknown }).message === "string"
+  ) {
+    return (e as { message: string }).message;
+  }
+  return String(e);
+}
+
+// The sandbox has no console/setTimeout/fetch: an extension touching those gets a
+// ReferenceError inside QuickJS, which surfaces as a normal per-script failure.
+// Never rejects — boot() runs unawaited, so a broken sandbox must not stop the app.
+export async function runExtensions(
+  engine: SumEngine,
+  scripts: { name: string; code: string }[],
+): Promise<void> {
+  if (scripts.length === 0) return;
+  try {
+    await load(engine, scripts);
+  } catch (e) {
+    logger.warn("extensions disabled: QuickJS sandbox unavailable:", e);
+  }
+}
+
+type RunWithTimeout = <T>(timeoutMs: number, fn: () => T) => T;
+
+function callGuest(
+  vm: QuickJSContext,
+  id: string,
+  fn: QuickJSHandle,
+  values: ExtensionValue[],
+  runWithTimeout: RunWithTimeout,
+): ExtensionValue | number {
+  // extension-sample.js convention: the callback takes one array of values.
+  const arr = vm.newArray();
+  try {
+    values.forEach((v, i) => {
+      const o = vm.newObject();
+      const d = vm.newNumber(v.double);
+      vm.setProp(o, "double", d);
+      d.dispose();
+      if (v.unitId) {
+        const u = vm.newString(v.unitId);
+        vm.setProp(o, "unitId", u);
+        u.dispose();
+      }
+      vm.setProp(arr, i, o);
+      o.dispose();
+    });
+    const res = runWithTimeout(CALL_TIMEOUT_MS, () =>
+      vm.callFunction(fn, vm.undefined, [arr]),
+    );
+    if (res.error) {
+      const err = vm.dump(res.error);
+      res.error.dispose();
+      throw new Error(`${id}: ${message(err)}`);
+    }
+    const out = vm.dump(res.value);
+    res.value.dispose();
+    return toExtValue(out, id);
+  } finally {
+    arr.dispose();
+  }
+}
+
+function exposeApi(
+  vm: QuickJSContext,
+  api: ExtensionApi,
+  runWithTimeout: RunWithTimeout,
+) {
+  const numi = vm.newObject();
+  const define = (name: string, impl: (...args: QuickJSHandle[]) => void) => {
+    const fn = vm.newFunction(name, (...args) => {
+      try {
+        impl(...args);
+      } catch (e) {
+        return { error: vm.newError(`numi.${name}: ${message(e)}`) };
+      }
+    });
+    vm.setProp(numi, name, fn);
+    fn.dispose();
+  };
+
+  define("setVariable", (nameHandle, valueHandle) => {
+    const name = vm.dump(nameHandle);
+    if (typeof name !== "string" || !name)
+      throw new Error("expects a variable name");
+    api.setVariable(name, toExtValue(vm.dump(valueHandle), "value"));
+  });
+
+  define("addUnit", (specHandle) => {
+    const spec = vm.dump(specHandle);
+    if (
+      !spec ||
+      typeof spec.id !== "string" ||
+      typeof spec.baseUnitId !== "string" ||
+      typeof spec.ratio !== "number"
+    ) {
+      throw new Error("expects { id, phrases, baseUnitId, ratio }");
+    }
+    api.addUnit({
+      id: spec.id,
+      phrases: typeof spec.phrases === "string" ? spec.phrases : spec.id,
+      baseUnitId: spec.baseUnitId,
+      ...(typeof spec.format === "string" ? { format: spec.format } : {}),
+      ratio: spec.ratio,
+    });
+  });
+
+  define("addFunction", (specHandle, fnHandle) => {
+    const spec = vm.dump(specHandle);
+    if (!spec || typeof spec.id !== "string")
+      throw new Error("expects { id, phrases }");
+    if (!fnHandle || vm.typeof(fnHandle) !== "function")
+      throw new Error("expects a function");
+    // outlives this callback, so it needs its own reference; the context is never disposed
+    const guestFn = fnHandle.dup();
+    const id = spec.id;
+    api.addFunction(
+      { id, phrases: typeof spec.phrases === "string" ? spec.phrases : id },
+      (values) => callGuest(vm, id, guestFn, values, runWithTimeout),
+    );
+  });
+
+  vm.setProp(vm.global, "numi", numi);
+  numi.dispose();
+}
+
+function evaluateScripts(
+  vm: QuickJSContext,
+  scripts: { name: string; code: string }[],
+  runWithTimeout: RunWithTimeout,
+) {
   for (const s of scripts) {
     try {
-      const fn = new Function("numi", s.code);
+      const res = runWithTimeout(LOAD_TIMEOUT_MS, () =>
-      fn(numi);
+        vm.evalCode(s.code, s.name),
+      );
+      if (res.error) {
+        const err = vm.dump(res.error);
+        res.error.dispose();
+        throw new Error(message(err));
+      }
+      res.value.dispose();
     } catch (e) {
-      console.error(`extension ${s.name} failed:`, e);
+      logger.error(`extension ${s.name} failed:`, e);
     }
   }
 }
+
+async function load(
+  engine: SumEngine,
+  scripts: { name: string; code: string }[],
+): Promise<void> {
+  const mod = await newQuickJSWASMModuleFromVariant(releaseSyncVariant);
+  const vm: QuickJSContext = mod.newContext();
+  vm.runtime.setMemoryLimit(MEMORY_LIMIT);
+  vm.runtime.setMaxStackSize(STACK_SIZE);
+
+  // Armed before every entry into the sandbox and disarmed after, so a hung script
+  // at load time and a hung function call on keystroke N are both bounded.
+  let deadline = Infinity;
+  vm.runtime.setInterruptHandler(() => now() > deadline);
+
+  const runWithTimeout: RunWithTimeout = (timeoutMs, fn) => {
+    deadline = now() + timeoutMs;
+    try {
+      return fn();
+    } finally {
+      deadline = Infinity;
+    }
+  };
+
+  exposeApi(vm, makeApi(engine), runWithTimeout);
+  evaluateScripts(vm, scripts, runWithTimeout);
+}

src/i18n.test.ts

@@ -0,0 +1,61 @@
+import { describe, it, expect, beforeEach, vi, afterEach } from "vitest";
+import { setLang, t, detectLang } from "./i18n";
+
+describe("i18n", () => {
+
+  beforeEach(() => {
+
+    const mockElements = [
+      { dataset: { i18n: "settings" }, textContent: "" },
+      { dataset: { i18n: "theme" }, textContent: "" }
+    ];
+
+    vi.stubGlobal("document", {
+      documentElement: { lang: "" },
+      querySelectorAll: vi.fn().mockReturnValue(mockElements)
+    });
+    vi.stubGlobal("navigator", { language: "en-US" });
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it("sets language and updates document lang", () => {
+    setLang("ru");
+    expect(t("settings")).toBe("Настройки");
+    expect(document.documentElement.lang).toBe("ru");
+
+    // Check if querySelectorAll was called and elements were updated
+    const elements = document.querySelectorAll("[data-i18n]");
+    expect(elements[0].textContent).toBe("Настройки");
+    expect(elements[1].textContent).toBe("Тема");
+
+    setLang("en");
+    expect(t("settings")).toBe("Settings");
+    expect(document.documentElement.lang).toBe("en");
+  });
+
+  it("falls back to en for unknown languages", () => {
+    setLang("fr");
+    expect(t("settings")).toBe("Settings");
+    expect(document.documentElement.lang).toBe("en");
+  });
+
+  it("falls back to en dictionary for missing keys in ru", () => {
+    // If a key exists in en but not ru, it should fallback to en
+    // we don't have one right now, but we can test missing keys in both
+    expect(t("unknown_key")).toBe("unknown_key");
+  });
+
+  it("detects language from navigator", () => {
+    vi.stubGlobal("navigator", { language: "ru-RU" });
+    expect(detectLang()).toBe("ru");
+
+    vi.stubGlobal("navigator", { language: "en-US" });
+    expect(detectLang()).toBe("en");
+
+    vi.stubGlobal("navigator", { language: undefined });
+    expect(detectLang()).toBe("en");
+  });
+});

src/logger.test.ts

@@ -0,0 +1,30 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { logger } from './logger';
+
+describe('logger', () => {
+  beforeEach(() => {
+    vi.spyOn(console, 'info').mockImplementation(() => {});
+    vi.spyOn(console, 'warn').mockImplementation(() => {});
+    vi.spyOn(console, 'error').mockImplementation(() => {});
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('should call console.info with correct arguments', () => {
+    logger.info('test info', { key: 'value' });
+    expect(console.info).toHaveBeenCalledWith('test info', { key: 'value' });
+  });
+
+  it('should call console.warn with correct arguments', () => {
+    logger.warn('test warn', 42);
+    expect(console.warn).toHaveBeenCalledWith('test warn', 42);
+  });
+
+  it('should call console.error with correct arguments', () => {
+    const error = new Error('test error');
+    logger.error('test error message', error);
+    expect(console.error).toHaveBeenCalledWith('test error message', error);
+  });
+});

src/logger.ts

@@ -0,0 +1,5 @@
+export const logger = {
+  info: (...args: any[]) => console.info(...args),
+  warn: (...args: any[]) => console.warn(...args),
+  error: (...args: any[]) => console.error(...args),
+};

src/main.test.ts

@@ -0,0 +1,127 @@
+import { test, vi, expect } from "vitest";
+
+vi.mock("./ui/editor", () => ({
+    SumEditor: vi.fn().mockImplementation(() => ({
+        goToLine: vi.fn(),
+        getSheetWithResults: vi.fn(() => "test-results"),
+        getText: vi.fn(() => "test"),
+        focus: vi.fn(),
+        refresh: vi.fn(),
+    }))
+}));
+
+vi.mock("@tauri-apps/api/core", () => ({
+    invoke: vi.fn(() => Promise.resolve(false)),
+}));
+
+vi.mock("@tauri-apps/api/window", () => ({
+    getCurrentWindow: vi.fn(() => ({
+        minimize: vi.fn(),
+        hide: vi.fn(),
+        show: vi.fn(),
+    })),
+}));
+
+vi.mock("./storage", async (importOriginal) => {
+    const actual = await importOriginal();
+    return {
+        ...actual as object,
+        isTauri: vi.fn(() => false),
+        loadSettings: vi.fn(() => ({ language: "en", autostart: false, alwaysOnTop: false, autoUpdateEnabled: false, sidebarVisible: false, hotkey: "CmdOrCtrl+Space" })),
+        loadAppData: vi.fn(() => ({ docs: [{id: "1", title: "Test"}], contents: {}, activeId: "1" })),
+        saveSettings: vi.fn(),
+        saveAppData: vi.fn(),
+        getLaunchFile: vi.fn(() => null),
+        flushAppData: vi.fn(),
+        onAppQuit: vi.fn((_cb: any) => {}),
+        onOpenFile: vi.fn(),
+        onFileDrop: vi.fn(),
+        registerHotkey: vi.fn(() => Promise.resolve(true)),
+        applyAutostart: vi.fn(),
+        applyAlwaysOnTop: vi.fn(),
+        fetchRates: vi.fn(),
+        fetchMarketData: vi.fn(),
+        loadExtensionScripts: vi.fn(() => Promise.resolve([])),
+    };
+});
+
+vi.mock("./ui/search", () => ({
+    initSearch: vi.fn(() => ({ open: vi.fn() }))
+}));
+
+vi.mock("./updater", () => ({
+    checkForUpdate: vi.fn(() => Promise.resolve(null))
+}));
+
+vi.mock("./extensions", () => ({
+    runExtensions: vi.fn(() => Promise.resolve())
+}));
+
+test("boot application", async () => {
+    const createMockElement = () => ({
+        addEventListener: vi.fn(),
+        removeEventListener: vi.fn(),
+        classList: { add: vi.fn(), remove: vi.fn(), toggle: vi.fn(), contains: vi.fn() },
+        style: { setProperty: vi.fn() },
+        dataset: {},
+        value: "",
+        appendChild: vi.fn(),
+        setAttribute: vi.fn(),
+        getBoundingClientRect: vi.fn(() => ({ right: 100, width: 100 })),
+        closest: vi.fn(),
+        blur: vi.fn(),
+        replaceChildren: vi.fn(),
+    });
+
+    const mock$ = vi.fn(createMockElement);
+
+    vi.stubGlobal("document", {
+        querySelector: mock$,
+        querySelectorAll: vi.fn(() => []), // For i18n
+        addEventListener: vi.fn(),
+        removeEventListener: vi.fn(),
+        body: createMockElement(),
+        documentElement: createMockElement(),
+        createElement: vi.fn(createMockElement),
+        createElementNS: vi.fn(createMockElement),
+        createDocumentFragment: vi.fn(createMockElement),
+        head: createMockElement(),
+    });
+
+    vi.stubGlobal("window", {
+        addEventListener: vi.fn(),
+        removeEventListener: vi.fn(),
+        performance: { now: () => 0 },
+        print: vi.fn(),
+        getSelection: vi.fn(() => null),
+        setInterval: vi.fn(),
+        setTimeout: vi.fn().mockImplementation((cb: Function) => cb()),
+        dispatchEvent: vi.fn(),
+        CustomEvent: vi.fn(),
+    });
+
+    vi.stubGlobal("matchMedia", vi.fn(() => ({
+        addEventListener: vi.fn(),
+        removeEventListener: vi.fn(),
+        matches: false,
+    })));
+
+    vi.stubGlobal("navigator", {
+        clipboard: { writeText: vi.fn() },
+        language: "en",
+    });
+
+    vi.stubGlobal("localStorage", {
+        getItem: vi.fn(() => null),
+        setItem: vi.fn(),
+    });
+
+    // Import main and wait for boot to complete
+    await import("./main");
+    await new Promise(r => setTimeout(r, 0));
+
+    // As mock is hoisted, we can import actual mocked funcs
+    const { loadSettings, loadAppData } = await import("./storage");
+    expect(loadSettings).toHaveBeenCalled();
+    expect(loadAppData).toHaveBeenCalled();
+});

src/storage.test.ts

@@ -0,0 +1,419 @@
+import { logger } from "./logger";
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { isTauri, loadSettings, saveSettings, defaultSettingsData, loadAppData, saveAppData, flushAppData, setDataDir, runBackups, backupDeletedSheet, openBackupsFolder, chooseFolder, dataDirHasDocuments, migrateDataDir, fetchRates, fetchHistoricalRates } from './storage';
+import { invoke } from '@tauri-apps/api/core';
+
+vi.mock('@tauri-apps/api/core', () => ({
+  invoke: vi.fn(),
+}));
+
+describe('storage', () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+    vi.stubGlobal('window', {});
+    vi.stubGlobal('localStorage', {
+      getItem: vi.fn(),
+      setItem: vi.fn(),
+    });
+    vi.spyOn(logger, 'warn').mockImplementation(() => {});
+    vi.stubGlobal('fetch', vi.fn());
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  describe('isTauri', () => {
+    it('returns false when not in Tauri', () => {
+      expect(isTauri()).toBe(false);
+    });
+
+    it('returns true when in Tauri', () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      expect(isTauri()).toBe(true);
+    });
+  });
+
+  describe('loadSettings', () => {
+    it('loads from localStorage when not in Tauri', async () => {
+      vi.mocked(localStorage.getItem).mockReturnValue(JSON.stringify({ precision: 5 }));
+      const settings = await loadSettings();
+      expect(localStorage.getItem).toHaveBeenCalledWith('summarum.settings');
+      expect(settings.precision).toBe(5);
+      expect(settings.theme).toBe(defaultSettingsData.theme);
+    });
+
+    it('loads via invoke when in Tauri', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      vi.mocked(invoke).mockResolvedValue(JSON.stringify({ precision: 8 }));
+      const settings = await loadSettings();
+      expect(invoke).toHaveBeenCalledWith('load_file', { name: 'settings.json' });
+      expect(settings.precision).toBe(8);
+      expect(settings.theme).toBe(defaultSettingsData.theme);
+    });
+
+    it('falls back to defaultSettingsData if localStorage throws', async () => {
+      vi.mocked(localStorage.getItem).mockImplementation(() => { throw new Error('localStorage error'); });
+      const settings = await loadSettings();
+      expect(logger.warn).toHaveBeenCalledWith('loadSettings failed', expect.any(Error));
+      expect(settings).toEqual(defaultSettingsData);
+    });
+
+    it('falls back to defaultSettingsData if invoke throws', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      vi.mocked(invoke).mockRejectedValue(new Error('invoke error'));
+      const settings = await loadSettings();
+      expect(logger.warn).toHaveBeenCalledWith('loadSettings failed', expect.any(Error));
+      expect(settings).toEqual(defaultSettingsData);
+    });
+
+    it('falls back to defaultSettingsData if localStorage returns null', async () => {
+      vi.mocked(localStorage.getItem).mockReturnValue(null);
+      const settings = await loadSettings();
+      expect(settings).toEqual(defaultSettingsData);
+    });
+
+    it('falls back to defaultSettingsData if JSON is invalid', async () => {
+      vi.mocked(localStorage.getItem).mockReturnValue("invalid json");
+      const settings = await loadSettings();
+      expect(logger.warn).toHaveBeenCalledWith('loadSettings failed', expect.any(Error));
+      expect(settings).toEqual(defaultSettingsData);
+    });
+  });
+
+  describe('saveSettings', () => {
+    it('saves to localStorage when not in Tauri', async () => {
+      const settings = { ...defaultSettingsData, precision: 10 };
+      await saveSettings(settings);
+      expect(localStorage.setItem).toHaveBeenCalledWith('summarum.settings', JSON.stringify(settings, null, 2));
+    });
+
+    it('saves via invoke when in Tauri', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      const settings = { ...defaultSettingsData, precision: 12 };
+      await saveSettings(settings);
+      expect(invoke).toHaveBeenCalledWith('save_file', { name: 'settings.json', contents: JSON.stringify(settings, null, 2) });
+    });
+  });
+
+  describe('loadAppData', () => {
+    const mockAppData = { docs: [], activeId: '1', contents: {} };
+
+    it('loads from localStorage when not in Tauri', async () => {
+      vi.mocked(localStorage.getItem).mockReturnValue(JSON.stringify(mockAppData));
+      const data = await loadAppData('');
+      expect(localStorage.getItem).toHaveBeenCalledWith('summarum.documents');
+      expect(data).toEqual(mockAppData);
+    });
+
+    it('loads via invoke when in Tauri', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      vi.mocked(invoke).mockResolvedValue(JSON.stringify(mockAppData));
+      const data = await loadAppData('');
+      expect(invoke).toHaveBeenCalledWith('load_documents', { dir: null });
+      expect(data).toEqual(mockAppData);
+    });
+
+    it('loads via invoke when in Tauri with specific dataDir', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      vi.mocked(invoke).mockResolvedValue(JSON.stringify(mockAppData));
+      const data = await loadAppData('custom_dir');
+      expect(invoke).toHaveBeenCalledWith('load_documents', { dir: 'custom_dir' });
+      expect(data).toEqual(mockAppData);
+    });
+
+    it('returns null if localStorage throws', async () => {
+      vi.mocked(localStorage.getItem).mockImplementation(() => { throw new Error('localStorage error'); });
+      const data = await loadAppData('');
+      expect(logger.warn).toHaveBeenCalledWith('loadAppData failed', expect.any(Error));
+      expect(data).toBeNull();
+    });
+
+    it('returns null if invoke throws', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      vi.mocked(invoke).mockRejectedValue(new Error('invoke error'));
+      const data = await loadAppData('');
+      expect(logger.warn).toHaveBeenCalledWith('loadAppData failed', expect.any(Error));
+      expect(data).toBeNull();
+    });
+
+    it('returns null if localStorage returns null', async () => {
+      vi.mocked(localStorage.getItem).mockReturnValue(null);
+      const data = await loadAppData('');
+      expect(data).toBeNull();
+    });
+
+    it('returns null if JSON is invalid', async () => {
+      vi.mocked(localStorage.getItem).mockReturnValue("invalid json");
+      const data = await loadAppData('');
+      expect(logger.warn).toHaveBeenCalledWith('loadAppData failed', expect.any(Error));
+      expect(data).toBeNull();
+    });
+  });
+
+  describe('saveAppData & flushAppData', () => {
+    const mockAppData = { docs: [], activeId: '1', contents: {} };
+
+    beforeEach(() => {
+      vi.useFakeTimers();
+    });
+
+    afterEach(() => {
+      vi.useRealTimers();
+    });
+
+    it('debounces saves and flushes correctly when not in Tauri', async () => {
+      setDataDir('');
+      saveAppData(mockAppData);
+
+      // Should not save immediately
+      expect(localStorage.setItem).not.toHaveBeenCalled();
+
+      // Fast forward past debounce time
+      vi.advanceTimersByTime(400);
+
+      expect(localStorage.setItem).toHaveBeenCalledWith('summarum.documents', JSON.stringify(mockAppData));
+    });
+
+    it('debounces saves and flushes correctly when in Tauri', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+
+      setDataDir('custom_dir');
+      saveAppData(mockAppData);
+
+      // Should not save immediately
+      expect(invoke).not.toHaveBeenCalled();
+
+      // Fast forward past debounce time
+      vi.runAllTimers();
+
+      // storage.ts's invoke wrapper does a dynamic import() before calling
+      // invoke(), which resolves over real event-loop ticks (module
+      // transform/IO) even with fake timers active — poll with real timers
+      // until it settles instead of guessing a fixed number of ticks.
+      vi.useRealTimers();
+      await vi.waitFor(() => {
+        expect(invoke).toHaveBeenCalledWith('save_documents', { dir: 'custom_dir', contents: JSON.stringify(mockAppData) });
+      });
+    });
+
+    it('flushAppData clears timer and saves immediately', async () => {
+      setDataDir('');
+      saveAppData(mockAppData);
+
+      await flushAppData();
+
+      expect(localStorage.setItem).toHaveBeenCalledWith('summarum.documents', JSON.stringify(mockAppData));
+
+      // Advancing timers should not trigger another save
+      vi.mocked(localStorage.setItem).mockClear();
+      vi.advanceTimersByTime(400);
+      expect(localStorage.setItem).not.toHaveBeenCalled();
+    });
+
+    it('flushAppData does nothing if no pending data', async () => {
+      await flushAppData();
+      expect(localStorage.setItem).not.toHaveBeenCalled();
+      expect(invoke).not.toHaveBeenCalled();
+    });
+
+    it('handles localStorage throw gracefully in flushAppData', async () => {
+      setDataDir('');
+      saveAppData(mockAppData);
+      vi.mocked(localStorage.setItem).mockImplementation(() => { throw new Error('localStorage error'); });
+
+      await flushAppData();
+
+      expect(logger.warn).toHaveBeenCalledWith('saveAppData failed', expect.any(Error));
+    });
+
+    it('handles invoke throw gracefully in flushAppData', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      setDataDir('');
+      saveAppData(mockAppData);
+      vi.mocked(invoke).mockRejectedValue(new Error('invoke error'));
+
+      await flushAppData();
+
+      expect(logger.warn).toHaveBeenCalledWith('saveAppData failed', expect.any(Error));
+    });
+  });
+
+  describe('backup and utility functions', () => {
+    describe('runBackups', () => {
+      it('does nothing when not in Tauri', async () => {
+        await runBackups('dir', 10);
+        expect(invoke).not.toHaveBeenCalled();
+      });
+
+      it('calls invoke when in Tauri', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        await runBackups('dir', 10);
+        expect(invoke).toHaveBeenCalledWith('run_backups', { dir: 'dir', retentionDays: 10 });
+      });
+
+      it('handles invoke throw gracefully', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        vi.mocked(invoke).mockRejectedValue(new Error('invoke error'));
+        await runBackups('dir', 10);
+        expect(logger.warn).toHaveBeenCalledWith('runBackups failed', expect.any(Error));
+      });
+    });
+
+    describe('backupDeletedSheet', () => {
+      it('does nothing when not in Tauri', async () => {
+        await backupDeletedSheet('dir', 'title', 'contents');
+        expect(invoke).not.toHaveBeenCalled();
+      });
+
+      it('does nothing if contents are empty', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        await backupDeletedSheet('dir', 'title', '   ');
+        expect(invoke).not.toHaveBeenCalled();
+      });
+
+      it('calls invoke when in Tauri with valid contents', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        await backupDeletedSheet('dir', 'title', 'contents');
+        expect(invoke).toHaveBeenCalledWith('backup_deleted_sheet', { dir: 'dir', title: 'title', contents: 'contents' });
+      });
+
+      it('handles invoke throw gracefully', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        vi.mocked(invoke).mockRejectedValue(new Error('invoke error'));
+        await backupDeletedSheet('dir', 'title', 'contents');
+        expect(logger.warn).toHaveBeenCalledWith('backupDeletedSheet failed', expect.any(Error));
+      });
+    });
+
+    describe('openBackupsFolder', () => {
+      it('does nothing when not in Tauri', async () => {
+        await openBackupsFolder('dir');
+        expect(invoke).not.toHaveBeenCalled();
+      });
+
+      it('calls invoke when in Tauri', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        await openBackupsFolder('dir');
+        expect(invoke).toHaveBeenCalledWith('open_backups_folder', { dir: 'dir' });
+      });
+    });
+
+    describe('chooseFolder', () => {
+      it('returns null when not in Tauri', async () => {
+        expect(await chooseFolder()).toBeNull();
+      });
+
+      it('returns path when in Tauri and folder is chosen', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        vi.mocked(invoke).mockResolvedValue('chosen_path');
+        expect(await chooseFolder()).toBe('chosen_path');
+        expect(invoke).toHaveBeenCalledWith('pick_data_dir', undefined);
+      });
+
+      it('returns null when in Tauri and folder choice is cancelled', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        vi.mocked(invoke).mockResolvedValue(null);
+        expect(await chooseFolder()).toBeNull();
+      });
+    });
+
+    describe('dataDirHasDocuments', () => {
+      it('returns false when not in Tauri', async () => {
+        expect(await dataDirHasDocuments('dir')).toBe(false);
+      });
+
+      it('calls invoke when in Tauri', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        vi.mocked(invoke).mockResolvedValue(true);
+        expect(await dataDirHasDocuments('dir')).toBe(true);
+        expect(invoke).toHaveBeenCalledWith('data_dir_has_documents', { dir: 'dir' });
+      });
+    });
+
+    describe('migrateDataDir', () => {
+      it('does nothing when not in Tauri', async () => {
+        await migrateDataDir('old', 'new', 'move');
+        expect(invoke).not.toHaveBeenCalled();
+      });
+
+      it('calls invoke when in Tauri', async () => {
+        vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+        await migrateDataDir('old', 'new', 'move');
+        expect(invoke).toHaveBeenCalledWith('migrate_data_dir', { oldDir: 'old', newDir: 'new', strategy: 'move' });
+      });
+    });
+  });
+
+  describe('fetchRates', () => {
+    it('uses invoke when in Tauri', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      const mockRates = { date: '2024-01-01', rates: { EUR: 0.85 }, fetchedAt: 12345 };
+      vi.mocked(invoke).mockResolvedValue(mockRates);
+
+      const result = await fetchRates(true);
+      expect(invoke).toHaveBeenCalledWith('fetch_rates', { force: true });
+      expect(result).toEqual(mockRates);
+    });
+
+    it('uses fetch when not in Tauri', async () => {
+      const mockResponse = { result: 'success', time_last_update_utc: '2024-01-01', rates: { EUR: 0.85 } };
+      vi.mocked(fetch).mockResolvedValue({ json: vi.fn().mockResolvedValue(mockResponse) } as unknown as Response);
+
+      const result = await fetchRates();
+      expect(fetch).toHaveBeenCalledWith('https://open.er-api.com/v6/latest/USD');
+      expect(result?.date).toBe('2024-01-01');
+      expect(result?.rates).toEqual({ EUR: 0.85 });
+      expect(result?.fetchedAt).toBeTypeOf('number');
+    });
+
+    it('returns null if fetch fails', async () => {
+      vi.mocked(fetch).mockRejectedValue(new Error('Network error'));
+      const result = await fetchRates();
+      expect(logger.warn).toHaveBeenCalledWith('fetchRates failed', expect.any(Error));
+      expect(result).toBeNull();
+    });
+
+    it('returns null if API result is not success', async () => {
+      const mockResponse = { result: 'error', 'error-type': 'unsupported-code' };
+      vi.mocked(fetch).mockResolvedValue({ json: vi.fn().mockResolvedValue(mockResponse) } as unknown as Response);
+      const result = await fetchRates();
+      expect(result).toBeNull();
+    });
+  });
+
+  describe('fetchHistoricalRates', () => {
+    it('uses invoke when in Tauri', async () => {
+      vi.stubGlobal('window', { __TAURI_INTERNALS__: {} });
+      const mockRates = { EUR: 0.85 };
+      vi.mocked(invoke).mockResolvedValue(mockRates);
+
+      const result = await fetchHistoricalRates('2024-01-01');
+      expect(invoke).toHaveBeenCalledWith('fetch_historical_rates', { date: '2024-01-01' });
+      expect(result).toEqual(mockRates);
+    });
+
+    it('uses fetch when not in Tauri and formats rates correctly', async () => {
+      const mockResponse = { rates: { EUR: 0.85, GBP: 0.75, JPY: -1 } }; // negative value should be ignored
+      vi.mocked(fetch).mockResolvedValue({ json: vi.fn().mockResolvedValue(mockResponse) } as unknown as Response);
+
+      const result = await fetchHistoricalRates('2024-01-01');
+      expect(fetch).toHaveBeenCalledWith('https://api.frankfurter.dev/v1/2024-01-01?from=USD');
+      expect(result).toEqual({ USD: 1, EUR: 0.85, GBP: 0.75 }); // USD: 1 added, negative ignored
+    });
+
+    it('returns null if fetch fails', async () => {
+      vi.mocked(fetch).mockRejectedValue(new Error('Network error'));
+      const result = await fetchHistoricalRates('2024-01-01');
+      expect(logger.warn).toHaveBeenCalledWith('fetchHistoricalRates failed', '2024-01-01', expect.any(Error));
+      expect(result).toBeNull();
+    });
+
+    it('returns null if rates missing in response', async () => {
+      const mockResponse = { amount: 1, base: 'USD', date: '2024-01-01' }; // missing rates
+      vi.mocked(fetch).mockResolvedValue({ json: vi.fn().mockResolvedValue(mockResponse) } as unknown as Response);
+      const result = await fetchHistoricalRates('2024-01-01');
+      expect(result).toBeNull();
+    });
+  });
+});

src/storage.ts

@@ -1,3 +1,4 @@
+import { logger } from "./logger";
 // Storage: Tauri commands in the app, localStorage fallback for `vite dev`.
 
 export interface DocMeta {
@@ -79,7 +80,7 @@ export async function loadSettings(): Promise<SettingsData> {
       : localStorage.getItem("summarum.settings");
     if (raw) return { ...defaultSettingsData, ...JSON.parse(raw) };
   } catch (e) {
-    console.warn("loadSettings failed", e);
+    logger.warn("loadSettings failed", e);
   }
   return { ...defaultSettingsData };
 }
@@ -99,7 +100,7 @@ export async function loadAppData(dataDir: string): Promise<AppData | null> {
       : localStorage.getItem("summarum.documents");
     if (raw) return JSON.parse(raw);
   } catch (e) {
-    console.warn("loadAppData failed", e);
+    logger.warn("loadAppData failed", e);
   }
   return null;
 }
@@ -132,7 +133,7 @@ export async function flushAppData(): Promise<void> {
     if (isTauri()) await invoke("save_documents", { dir: dirArg(currentDataDir), contents: raw });
     else localStorage.setItem("summarum.documents", raw);
   } catch (e) {
-    console.warn("saveAppData failed", e);
+    logger.warn("saveAppData failed", e);
   }
 }
 
@@ -150,7 +151,7 @@ export async function runBackups(dataDir: string, retentionDays: number): Promis
   try {
     await invoke("run_backups", { dir: dirArg(dataDir), retentionDays });
   } catch (e) {
-    console.warn("runBackups failed", e);
+    logger.warn("runBackups failed", e);
   }
 }
 
@@ -159,7 +160,7 @@ export async function backupDeletedSheet(dataDir: string, title: string, content
   try {
     await invoke("backup_deleted_sheet", { dir: dirArg(dataDir), title, contents });
   } catch (e) {
-    console.warn("backupDeletedSheet failed", e);
+    logger.warn("backupDeletedSheet failed", e);
   }
 }
 
@@ -167,11 +168,10 @@ export async function openBackupsFolder(dataDir: string): Promise<void> {
   if (isTauri()) await invoke("open_backups_folder", { dir: dirArg(dataDir) });
 }
 
+/** Rust-side picker: migrateDataDir only accepts a folder chosen through this. */
 export async function chooseFolder(): Promise<string | null> {
   if (!isTauri()) return null;
-  const { open } = await import("@tauri-apps/plugin-dialog");
+  return (await invoke<string | null>("pick_data_dir")) ?? null;
-  const picked = await open({ directory: true, multiple: false });
-  return typeof picked === "string" ? picked : null;
 }
 
 export async function dataDirHasDocuments(dir: string): Promise<boolean> {
@@ -206,13 +206,33 @@ export async function fetchRates(force = false): Promise<RatesPayload | null> {
       return { date: json.time_last_update_utc, rates: json.rates, fetchedAt: Math.floor(Date.now() / 1000) };
     }
   } catch (e) {
-    console.warn("fetchRates failed", e);
+    logger.warn("fetchRates failed", e);
   }
   return null;
 }
 
 // ---------- historical rates
 
+export async function fetchHistoricalRatesBatch(dates: string[]): Promise<Record<string, Record<string, number>>> {
+  if (dates.length === 0) return {};
+  try {
+    if (isTauri()) {
+      return await invoke<Record<string, Record<string, number>>>("fetch_historical_rates_batch", { dates });
+    }
+    const results: Record<string, Record<string, number>> = {};
+    await Promise.all(
+      dates.map(async (date) => {
+        const rates = await fetchHistoricalRates(date);
+        if (rates) results[date] = rates;
+      })
+    );
+    return results;
+  } catch (e) {
+    logger.warn("fetchHistoricalRatesBatch failed", e);
+    return {};
+  }
+}
+
 export async function fetchHistoricalRates(date: string): Promise<Record<string, number> | null> {
   try {
     if (isTauri()) {
@@ -227,16 +247,16 @@ export async function fetchHistoricalRates(date: string): Promise<Record<string,
     }
     return out;
   } catch (e) {
-    console.warn("fetchHistoricalRates failed", date, e);
+    logger.warn("fetchHistoricalRates failed", date, e);
     return null;
   }
 }
 
 // ---------- image export
 
-export async function writeImageFile(path: string, dataBase64: string): Promise<void> {
+export async function writeImageFile(dataBase64: string): Promise<boolean> {
-  if (!isTauri()) return;
+  if (!isTauri()) return false;
-  await invoke("write_image_file", { path, dataBase64 });
+  return invoke("write_image_file", { dataBase64 });
 }
 
 // ---------- market data
@@ -246,7 +266,7 @@ export async function fetchMarketData(symbols: string[]): Promise<Record<string,
   try {
     return await invoke<Record<string, number>>("fetch_market_data", { symbols });
   } catch (e) {
-    console.warn("fetchMarketData failed", e);
+    logger.warn("fetchMarketData failed", e);
     return {};
   }
 }
@@ -258,7 +278,7 @@ export async function loadExtensionScripts(): Promise<{ name: string; code: stri
   try {
     return await invoke<{ name: string; code: string }[]>("load_extensions");
   } catch (e) {
-    console.warn("loadExtensions failed", e);
+    logger.warn("loadExtensions failed", e);
     return [];
   }
 }
@@ -295,7 +315,7 @@ export async function onFileDrop(cb: (content: string) => void): Promise<void> {
           const content = await invoke<string>("read_text_file", { path });
           cb(content);
         } catch (e) {
-          console.warn("file drop rejected", path, e);
+          logger.warn("file drop rejected", path, e);
         }
       }
     });

src/ui/app.css

@@ -654,3 +654,4 @@ body {
 }
 .cm-tooltip-autocomplete ul li { font-family: var(--mono); font-size: 13px; color: var(--fg); }
 .cm-tooltip-autocomplete ul li[aria-selected] { background: var(--sel); color: var(--fg); }
+.d-none { display: none !important; }

src/ui/editor.ts

@@ -1,10 +1,11 @@
 // CodeMirror editor wired to the engine: evaluates on change, highlights
 // engine tokens, renders the results overlay, autocompletes phrases.
-import { EditorView, ViewUpdate, Decoration, DecorationSet, keymap, drawSelection } from "@codemirror/view";
+import { EditorView, ViewPlugin, ViewUpdate, Decoration, DecorationSet, keymap, drawSelection } from "@codemirror/view";
 import { EditorState, StateEffect, StateField, RangeSetBuilder } from "@codemirror/state";
 import { defaultKeymap, history, historyKeymap } from "@codemirror/commands";
 import { autocompletion, CompletionContext, CompletionResult, acceptCompletion } from "@codemirror/autocomplete";
 import { SumEngine, LineResult } from "../engine";
+import { buildSparkline } from "./sparkline";
 
 export interface EditorCallbacks {
   onChange(text: string): void;
@@ -65,12 +66,17 @@ function buildDecorations(state: EditorState): DecorationSet {
 
 const highlightField = StateField.define<DecorationSet>({
   create: buildDecorations,
-  update(_value, tr) {
+  update(value, tr) {
-    return buildDecorations(tr.state);
+    const hasResults = tr.effects.some((e) => e.is(setResults));
+    if (hasResults) return buildDecorations(tr.state);
+    if (tr.docChanged) return value.map(tr.changes);
+    return value;
   },
   provide: (f) => EditorView.decorations.from(f),
 });
 
+const varHighlightReCache = new Map<string, { assignment: RegExp; highlight: RegExp }>();
+
 /** Highlights every occurrence of the variable under the cursor. */
 function buildVarHighlight(state: EditorState): DecorationSet {
   const builder = new RangeSetBuilder<Decoration>();
@@ -86,69 +92,67 @@ function buildVarHighlight(state: EditorState): DecorationSet {
   if (a === b) return builder.finish();
   const word = text.slice(a, b);
   if (!/^[\p{L}_][\p{L}\d_]*$/u.test(word)) return builder.finish();
-  // only highlight if the word is actually assigned somewhere in the document
+
+  let cachedRe = varHighlightReCache.get(word);
+  if (!cachedRe) {
     const esc = word.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
-  if (!new RegExp(`^\\s*${esc}\\s*=`, "mu").test(text)) return builder.finish();
+    cachedRe = {
-  const re = new RegExp(`(?<![\\p{L}\\d_])${esc}(?![\\p{L}\\d_])`, "gu");
+      assignment: new RegExp(`^\\s*${esc}\\s*=`, "mu"),
-  for (const m of text.matchAll(re)) {
+      highlight: new RegExp(`(?<![\\p{L}\\d_])${esc}(?![\\p{L}\\d_])`, "gu"),
+    };
+    if (varHighlightReCache.size > 1000) varHighlightReCache.clear();
+    varHighlightReCache.set(word, cachedRe);
+  }
+
+  // only highlight if the word is actually assigned somewhere in the document
+  if (!cachedRe.assignment.test(text)) return builder.finish();
+  for (const m of text.matchAll(cachedRe.highlight)) {
     builder.add(m.index, m.index + word.length, Decoration.mark({ class: "tok-var-active" }));
   }
   return builder.finish();
 }
 
+const setVarHighlight = StateEffect.define<DecorationSet>();
+
 const varHighlightField = StateField.define<DecorationSet>({
-  create: buildVarHighlight,
+  create: () => Decoration.none,
-  update(_value, tr) {
+  update(value, tr) {
-    return buildVarHighlight(tr.state);
+    for (const e of tr.effects) {
+      if (e.is(setVarHighlight)) return e.value;
+    }
+    if (tr.docChanged) return value.map(tr.changes);
+    return value;
   },
   provide: (f) => EditorView.decorations.from(f),
 });
 
-function buildSparkline(pts: number[], top: number): SVGSVGElement {
+const varHighlightPlugin = ViewPlugin.fromClass(
-  const NS = "http://www.w3.org/2000/svg";
+  class {
-  const W = 80, H = 20, pad = 2;
+    timeout: ReturnType<typeof setTimeout> | null = null;
-  const svg = document.createElementNS(NS, "svg") as SVGSVGElement;
+
-  svg.setAttribute("width", String(W));
+    constructor(view: EditorView) {
-  svg.setAttribute("height", String(H));
+      this.schedule(view);
-  svg.setAttribute("viewBox", `0 0 ${W} ${H}`);
-  svg.classList.add("result-sparkline");
-  svg.style.top = `${top}px`;
-  const min = Math.min(...pts), max = Math.max(...pts);
-  if (min === max) {
-    const line = document.createElementNS(NS, "line");
-    line.setAttribute("x1", String(pad));
-    line.setAttribute("y1", String(H / 2));
-    line.setAttribute("x2", String(W - pad));
-    line.setAttribute("y2", String(H / 2));
-    line.setAttribute("stroke", "var(--result)");
-    line.setAttribute("stroke-width", "1.5");
-    svg.appendChild(line);
-  } else {
-    const coords = pts.map((v, i) => {
-      const x = pad + (i / (pts.length - 1)) * (W - 2 * pad);
-      const y = pad + (1 - (v - min) / (max - min)) * (H - 2 * pad);
-      return `${x.toFixed(1)},${y.toFixed(1)}`;
-    }).join(" ");
-    const poly = document.createElementNS(NS, "polyline");
-    poly.setAttribute("points", coords);
-    poly.setAttribute("fill", "none");
-    poly.setAttribute("stroke", "var(--result)");
-    poly.setAttribute("stroke-width", "1.5");
-    poly.setAttribute("stroke-linecap", "round");
-    poly.setAttribute("stroke-linejoin", "round");
-    svg.appendChild(poly);
-    const last = pts[pts.length - 1];
-    const cx = (W - pad).toFixed(1);
-    const cy = (pad + (1 - (last - min) / (max - min)) * (H - 2 * pad)).toFixed(1);
-    const dot = document.createElementNS(NS, "circle");
-    dot.setAttribute("cx", cx);
-    dot.setAttribute("cy", cy);
-    dot.setAttribute("r", "2");
-    dot.setAttribute("fill", "var(--result)");
-    svg.appendChild(dot);
     }
-  return svg;
+
-}
+    update(update: ViewUpdate) {
+      if (update.docChanged || update.selectionSet) {
+        this.schedule(update.view);
+      }
+    }
+
+    schedule(view: EditorView) {
+      if (this.timeout) clearTimeout(this.timeout);
+      this.timeout = setTimeout(() => {
+        const decos = buildVarHighlight(view.state);
+        view.dispatch({ effects: setVarHighlight.of(decos) });
+      }, 150);
+    }
+
+    destroy() {
+      if (this.timeout) clearTimeout(this.timeout);
+    }
+  }
+);
 
 export class SumEditor {
   view: EditorView;
@@ -166,6 +170,7 @@ export class SumEditor {
     this.resultsEl = resultsEl;
 
     let engineOptions: { label: string; type: string; detail?: string }[] | null = null;
+    const varPattern = /^\s*([\p{L}_][\p{L}\d_]*)\s*=/u;
     const completionSource = (ctx: CompletionContext): CompletionResult | null => {
       const word = ctx.matchBefore(/[\p{L}_]+$/u);
       if (!word || (word.from === word.to && !ctx.explicit)) return null;
@@ -178,10 +183,16 @@ export class SumEditor {
       }));
       const options = [...engineOptions];
       // document variables
-      const text = ctx.state.doc.toString();
+      const iter = ctx.state.doc.iterLines();
-      for (const m of text.matchAll(/^\s*([\p{L}_][\p{L}\d_]*)\s*=/gmu)) {
+      for (let next = iter.next(); !next.done; next = iter.next()) {
+        const line = next.value;
+        if (line.includes("=")) {
+          const m = varPattern.exec(line);
+          if (m) {
             options.push({ label: m[1], type: "variable" });
           }
+        }
+      }
       return { from: word.from, options, validFor: /^[\p{L}_]*$/u };
     };
 
@@ -197,6 +208,7 @@ export class SumEditor {
           resultsField,
           highlightField,
           varHighlightField,
+          varHighlightPlugin,
           EditorView.lineWrapping,
           drawSelection({ cursorBlinkRate: 1000 }),
           // CM injects its base styles at runtime after app.css, so layout

src/ui/export.test.ts

@@ -0,0 +1,171 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { exportSheetImage } from './export';
+import { writeImageFile } from '../storage';
+
+vi.mock('../storage', () => ({
+  writeImageFile: vi.fn(),
+}));
+
+describe('exportSheetImage', () => {
+  let mockContext2D: any;
+  let mockCanvas: any;
+  let toastMock: any;
+  let tMock: any;
+
+  beforeEach(() => {
+    toastMock = vi.fn();
+    tMock = vi.fn((key: string) => `trans_${key}`);
+
+    mockContext2D = {
+      measureText: vi.fn().mockReturnValue({ width: 10 }),
+      scale: vi.fn(),
+      fillRect: vi.fn(),
+      fillText: vi.fn(),
+      font: '',
+      fillStyle: '',
+    };
+
+    mockCanvas = {
+      getContext: vi.fn().mockReturnValue(mockContext2D),
+      toBlob: vi.fn((cb) => cb(new Blob(['fake-image-data'], { type: 'image/png' }))),
+      width: 0,
+      height: 0,
+    };
+
+    vi.stubGlobal('document', {
+      documentElement: {},
+      createElement: vi.fn((tag) => {
+        if (tag === 'canvas') return mockCanvas;
+        return {};
+      })
+    });
+
+    vi.stubGlobal('window', {
+      devicePixelRatio: 0
+    });
+
+    vi.stubGlobal('getComputedStyle', vi.fn().mockReturnValue({
+      getPropertyValue: vi.fn((prop) => {
+        if (prop === '--bg') return '';
+        if (prop === '--fg') return '';
+        if (prop === '--result') return '';
+        if (prop === '--mono') return '';
+        return '';
+      })
+    }));
+
+    vi.stubGlobal('Blob', class Blob {
+      content: any[];
+      options: any;
+      constructor(content: any[], options: any) {
+        this.content = content;
+        this.options = options;
+      }
+      async arrayBuffer() {
+        return new Uint8Array([1, 2, 3]).buffer;
+      }
+    });
+
+    vi.stubGlobal('ClipboardItem', class ClipboardItem {
+      constructor(data: any) {
+        Object.assign(this, data);
+      }
+    });
+
+    vi.stubGlobal('navigator', {
+      clipboard: {
+        write: vi.fn().mockResolvedValue(undefined)
+      }
+    });
+
+    vi.stubGlobal('btoa', (str: string) => Buffer.from(str, 'binary').toString('base64'));
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    vi.clearAllMocks();
+  });
+
+  it('should create a canvas and copy it to clipboard successfully', async () => {
+    await exportSheetImage({
+      lines: ['1 + 1'],
+      results: [{ text: '2' }],
+      fontSize: 14,
+      toast: toastMock,
+      t: tMock
+    });
+
+    expect(document.createElement).toHaveBeenCalledWith('canvas');
+    expect(mockCanvas.getContext).toHaveBeenCalledWith('2d');
+    expect(mockContext2D.fillText).toHaveBeenCalledWith('1 + 1', expect.any(Number), expect.any(Number));
+    expect(mockContext2D.fillText).toHaveBeenCalledWith('2', expect.any(Number), expect.any(Number));
+
+    expect(navigator.clipboard.write).toHaveBeenCalled();
+    expect(toastMock).toHaveBeenCalledWith('trans_imageCopied');
+  });
+
+  it('should handle blob failure', async () => {
+    mockCanvas.toBlob = vi.fn((cb) => cb(null));
+
+    await exportSheetImage({
+      lines: ['test'],
+      results: [{ text: null }],
+      fontSize: 14,
+      toast: toastMock,
+      t: tMock
+    });
+
+    expect(toastMock).toHaveBeenCalledWith('trans_imageFailed');
+    expect(navigator.clipboard.write).not.toHaveBeenCalled();
+  });
+
+  it('should fallback to writeImageFile when clipboard write fails', async () => {
+    navigator.clipboard.write = vi.fn().mockRejectedValue(new Error('clipboard fail'));
+    vi.mocked(writeImageFile).mockResolvedValue(true);
+
+    await exportSheetImage({
+      lines: ['fallback'],
+      results: [{ text: 'res' }],
+      fontSize: 14,
+      toast: toastMock,
+      t: tMock
+    });
+
+    expect(navigator.clipboard.write).toHaveBeenCalled();
+    expect(writeImageFile).toHaveBeenCalled();
+    expect(writeImageFile).toHaveBeenCalledWith('AQID');
+    expect(toastMock).toHaveBeenCalledWith('trans_saved');
+  });
+
+  it('should handle writeImageFile failure in fallback', async () => {
+    navigator.clipboard.write = vi.fn().mockRejectedValue(new Error('clipboard fail'));
+    vi.mocked(writeImageFile).mockRejectedValue(new Error('save fail'));
+
+    await exportSheetImage({
+      lines: ['fail'],
+      results: [{ text: 'res' }],
+      fontSize: 14,
+      toast: toastMock,
+      t: tMock
+    });
+
+    expect(writeImageFile).toHaveBeenCalled();
+    expect(toastMock).toHaveBeenCalledWith('trans_imageFailed');
+  });
+
+  it('should handle writeImageFile returning false', async () => {
+    navigator.clipboard.write = vi.fn().mockRejectedValue(new Error('clipboard fail'));
+    vi.mocked(writeImageFile).mockResolvedValue(false);
+
+    await exportSheetImage({
+      lines: ['fail'],
+      results: [{ text: 'res' }],
+      fontSize: 14,
+      toast: toastMock,
+      t: tMock
+    });
+
+    expect(writeImageFile).toHaveBeenCalled();
+    expect(toastMock).not.toHaveBeenCalledWith('trans_saved');
+  });
+});

src/ui/export.ts

@@ -58,12 +58,9 @@ export async function exportSheetImage(deps: ExportImageDeps): Promise<void> {
   } catch {
     // clipboard API failed — save to file
     try {
-      const { save } = await import("@tauri-apps/plugin-dialog");
-      const path = await save({ filters: [{ name: "PNG Image", extensions: ["png"] }] });
-      if (path) {
       const buf = await blob.arrayBuffer();
       const b64 = bytesToBase64(new Uint8Array(buf));
-        await writeImageFile(path, b64);
+      if (await writeImageFile(b64)) {
         toast(t("saved"));
       }
     } catch {

src/ui/search.test.ts

@@ -0,0 +1,243 @@
+import { describe, it, expect, vi } from "vitest";
+import { SumEngine } from "../engine";
+import { parseResultQuery, searchAllSheets, SearchDeps, SearchDoc } from "./search";
+import { Workspace } from "../workspace";
+import Decimal from "decimal.js";
+
+describe("parseResultQuery", () => {
+  const engine = new SumEngine();
+
+  it("parses '>=' operator correctly", () => {
+    const res = parseResultQuery(engine, ">= 100");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe(">=");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(100))).toBe(true);
+    }
+  });
+
+  it("parses '<=' operator correctly", () => {
+    const res = parseResultQuery(engine, "<= 50");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe("<=");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(50))).toBe(true);
+    }
+  });
+
+  it("parses '>' operator correctly", () => {
+    const res = parseResultQuery(engine, "> 0");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe(">");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(0))).toBe(true);
+    }
+  });
+
+  it("parses '<' operator correctly", () => {
+    const res = parseResultQuery(engine, "< -10");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe("<");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(-10))).toBe(true);
+    }
+  });
+
+  it("parses '=' operator correctly", () => {
+    const res = parseResultQuery(engine, "= 42.5");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe("=");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(42.5))).toBe(true);
+    }
+  });
+
+  it("parses '~' operator correctly", () => {
+    const res = parseResultQuery(engine, "~ 3.14");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe("~");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(3.14))).toBe(true);
+    }
+  });
+
+  it("handles whitespace correctly", () => {
+    const res = parseResultQuery(engine, "   >=    200   ");
+    expect(res).not.toBeNull();
+    expect(res?.op).toBe(">=");
+    expect(res?.threshold.kind).toBe("quantity");
+    if (res?.threshold.kind === "quantity") {
+      expect(res.threshold.value.eq(new Decimal(200))).toBe(true);
+    }
+  });
+
+  it("returns null for invalid operator", () => {
+    const res = parseResultQuery(engine, "!= 100");
+    expect(res).toBeNull();
+  });
+
+  it("returns null for invalid value string", () => {
+    // "abc" cannot be evaluated to a quantity
+    const res = parseResultQuery(engine, ">= abc");
+    expect(res).toBeNull();
+  });
+
+  it("returns null for empty string", () => {
+    const res = parseResultQuery(engine, "");
+    expect(res).toBeNull();
+  });
+
+  it("returns null when no expression matches after operator", () => {
+    const res = parseResultQuery(engine, ">=");
+    expect(res).toBeNull();
+  });
+});
+
+describe("searchAllSheets", () => {
+  it("returns empty array for empty query", () => {
+    const deps = {} as SearchDeps;
+    expect(searchAllSheets(deps, "   ")).toEqual([]);
+  });
+
+  it("performs full-text search across multiple sheets", () => {
+    const docs: SearchDoc[] = [
+      { id: "1", title: "Doc 1", text: "Hello world\nThis is a test" },
+      { id: "2", title: "Doc 2", text: "Another test\nNothing here" },
+    ];
+    const deps = {
+      docs: () => docs,
+      engine: new SumEngine(),
+    } as SearchDeps;
+
+    const hits = searchAllSheets(deps, "test");
+    expect(hits).toHaveLength(2);
+    expect(hits[0]).toMatchObject({ docId: "1", docTitle: "Doc 1", line: 2, text: "This is a test" });
+    expect(hits[1]).toMatchObject({ docId: "2", docTitle: "Doc 2", line: 1, text: "Another test" });
+  });
+
+  it("limits results to 200 hits for text search", () => {
+    const lines = Array(250).fill("test string");
+    const docs: SearchDoc[] = [
+      { id: "1", title: "Doc 1", text: lines.join("\n") },
+    ];
+    const deps = {
+      docs: () => docs,
+      engine: new SumEngine(),
+    } as SearchDeps;
+
+    const hits = searchAllSheets(deps, "test");
+    expect(hits).toHaveLength(200);
+  });
+
+  describe("numeric threshold search", () => {
+    const engine = new SumEngine();
+
+    const createMockWorkspace = (results: any[]) => {
+      return {
+        getCachedResults: vi.fn().mockReturnValue(results)
+      } as unknown as Workspace;
+    };
+
+    it("matches exact value (=)", () => {
+      const docs: SearchDoc[] = [{ id: "1", title: "Doc 1", text: "100" }];
+      const workspace = createMockWorkspace([{
+        value: { kind: "quantity", value: new Decimal(100) },
+        text: "100"
+      }]);
+
+      const deps = {
+        docs: () => docs,
+        engine,
+        workspace,
+      } as unknown as SearchDeps;
+
+      const hits = searchAllSheets(deps, "= 100");
+      expect(hits).toHaveLength(1);
+      expect(hits[0]).toMatchObject({ docId: "1", line: 1, result: "100" });
+
+      const noHits = searchAllSheets(deps, "= 99");
+      expect(noHits).toHaveLength(0);
+    });
+
+    it("matches greater than (>)", () => {
+      const docs: SearchDoc[] = [{ id: "1", title: "Doc 1", text: "150\n50" }];
+      const workspace = createMockWorkspace([
+        { value: { kind: "quantity", value: new Decimal(150) }, text: "150" },
+        { value: { kind: "quantity", value: new Decimal(50) }, text: "50" }
+      ]);
+
+      const deps = {
+        docs: () => docs,
+        engine,
+        workspace,
+      } as unknown as SearchDeps;
+
+      const hits = searchAllSheets(deps, "> 100");
+      expect(hits).toHaveLength(1);
+      expect(hits[0].line).toBe(1);
+    });
+
+    it("matches approximate value (~)", () => {
+      const docs: SearchDoc[] = [{ id: "1", title: "Doc 1", text: "100.5\n99.5\n105" }];
+      const workspace = createMockWorkspace([
+        { value: { kind: "quantity", value: new Decimal(100.5) }, text: "100.5" },
+        { value: { kind: "quantity", value: new Decimal(99.5) }, text: "99.5" },
+        { value: { kind: "quantity", value: new Decimal(105) }, text: "105" }
+      ]);
+
+      const deps = {
+        docs: () => docs,
+        engine,
+        workspace,
+      } as unknown as SearchDeps;
+
+      const hits = searchAllSheets(deps, "~ 100");
+      expect(hits).toHaveLength(2); // 100.5 and 99.5 are within 1% of 100
+      expect(hits[0].line).toBe(1);
+      expect(hits[1].line).toBe(2);
+    });
+
+    it("ignores non-quantity results during numeric search", () => {
+      const docs: SearchDoc[] = [{ id: "1", title: "Doc 1", text: "100\nnot a number" }];
+      const workspace = createMockWorkspace([
+        { value: { kind: "quantity", value: new Decimal(100) }, text: "100" },
+        { value: null, text: null }
+      ]);
+
+      const deps = {
+        docs: () => docs,
+        engine,
+        workspace,
+      } as unknown as SearchDeps;
+
+      const hits = searchAllSheets(deps, "> 50");
+      expect(hits).toHaveLength(1);
+    });
+
+    it("limits results to 200 hits for numeric search", () => {
+      const lines = Array(250).fill("100");
+      const docs: SearchDoc[] = [{ id: "1", title: "Doc 1", text: lines.join("\n") }];
+
+      const results = Array(250).fill({
+        value: { kind: "quantity", value: new Decimal(100) },
+        text: "100"
+      });
+      const workspace = createMockWorkspace(results);
+
+      const deps = {
+        docs: () => docs,
+        engine,
+        workspace,
+      } as unknown as SearchDeps;
+
+      const hits = searchAllSheets(deps, "> 50");
+      expect(hits).toHaveLength(200);
+    });
+  });
+});

src/ui/search.ts

@@ -30,9 +30,13 @@ export interface SearchController {
   open(): void;
 }
 
-const $ = <T extends HTMLElement>(sel: string): T => document.querySelector(sel) as T;
+const $ = <T extends HTMLElement>(sel: string): T =>
+  document.querySelector(sel) as T;
 
-function parseResultQuery(engine: SumEngine, q: string): { op: string; threshold: Value } | null {
+export function parseResultQuery(
+  engine: SumEngine,
+  q: string,
+): { op: string; threshold: Value } | null {
   const m = /^(>=|<=|>|<|=|~)\s*(.+)$/.exec(q.trim());
   if (!m) return null;
   const v = engine.evaluateExpression(m[2].trim());
@@ -40,7 +44,7 @@ function parseResultQuery(engine: SumEngine, q: string): { op: string; threshold
   return { op: m[1], threshold: v };
 }
 
-function searchAllSheets(deps: SearchDeps, query: string): SearchHit[] {
+export function searchAllSheets(deps: SearchDeps, query: string): SearchHit[] {
   const q = query.trim();
   if (!q) return [];
   const docs = deps.docs();
@@ -49,23 +53,42 @@ function searchAllSheets(deps: SearchDeps, query: string): SearchHit[] {
     const th = rq.threshold.value;
     const hits: SearchHit[] = [];
     for (const doc of docs) {
-      const results = deps.workspace.evaluateSheet(doc.id, doc.text);
+      const results = deps.workspace.getCachedResults(doc);
-      const lines = doc.text.split("\n");
+      let lines: string[] | undefined;
       for (let i = 0; i < results.length; i++) {
         const r = results[i];
         if (!r.value || r.value.kind !== "quantity") continue;
         const v = r.value.value;
         let match = false;
         switch (rq.op) {
-          case ">":  match = v.gt(th); break;
+          case ">":
-          case ">=": match = v.gte(th); break;
+            match = v.gt(th);
-          case "<":  match = v.lt(th); break;
+            break;
-          case "<=": match = v.lte(th); break;
+          case ">=":
-          case "=":  match = v.eq(th); break;
+            match = v.gte(th);
-          case "~":  match = !th.isZero() && v.minus(th).abs().div(th.abs()).lte(0.01); break;
+            break;
+          case "<":
+            match = v.lt(th);
+            break;
+          case "<=":
+            match = v.lte(th);
+            break;
+          case "=":
+            match = v.eq(th);
+            break;
+          case "~":
+            match = !th.isZero() && v.minus(th).abs().div(th.abs()).lte(0.01);
+            break;
         }
         if (match) {
-          hits.push({ docId: doc.id, docTitle: doc.title, line: i + 1, text: lines[i] ?? "", result: r.text ?? undefined });
+          if (!lines) lines = doc.text.split("\n");
+          hits.push({
+            docId: doc.id,
+            docTitle: doc.title,
+            line: i + 1,
+            text: lines[i] ?? "",
+            result: r.text ?? undefined,
+          });
           if (hits.length >= 200) return hits;
         }
       }
@@ -78,7 +101,12 @@ function searchAllSheets(deps: SearchDeps, query: string): SearchHit[] {
     const lines = doc.text.split("\n");
     for (let i = 0; i < lines.length; i++) {
       if (lines[i].toLowerCase().includes(ql)) {
-        hits.push({ docId: doc.id, docTitle: doc.title, line: i + 1, text: lines[i] });
+        hits.push({
+          docId: doc.id,
+          docTitle: doc.title,
+          line: i + 1,
+          text: lines[i],
+        });
         if (hits.length >= 200) return hits;
       }
     }
@@ -113,7 +141,9 @@ export function initSearch(deps: SearchDeps): SearchController {
       docEl.textContent = hit.docTitle;
       const lineEl = document.createElement("div");
       lineEl.className = "line";
-      lineEl.textContent = hit.result ? `${hit.text} = ${hit.result}` : hit.text;
+      lineEl.textContent = hit.result
+        ? `${hit.text} = ${hit.result}`
+        : hit.text;
       item.append(docEl, lineEl);
       item.addEventListener("click", () => {
         deps.onOpen(hit.docId, hit.line);

src/ui/sparkline.test.ts

@@ -0,0 +1,115 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import { buildSparkline } from "./sparkline";
+
+describe("buildSparkline", () => {
+  beforeEach(() => {
+    vi.stubGlobal("document", {
+      createElementNS: vi.fn((ns, tag) => {
+        const attributes: Record<string, string> = {};
+        const classes: string[] = [];
+        const children: any[] = [];
+        const style: Record<string, string> = {};
+
+        return {
+          tagName: tag,
+          namespaceURI: ns,
+          setAttribute: vi.fn((key, val) => {
+            attributes[key] = val;
+          }),
+          getAttribute: vi.fn((key) => attributes[key]),
+          classList: {
+            add: vi.fn((cls) => {
+              classes.push(cls);
+            }),
+            contains: vi.fn((cls) => classes.includes(cls)),
+          },
+          style,
+          appendChild: vi.fn((child) => {
+            children.push(child);
+          }),
+          _getAttributes: () => attributes,
+          _getClasses: () => classes,
+          _getChildren: () => children,
+        };
+      }),
+    });
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it("creates a base SVG element with correct attributes and style", () => {
+    const pts = [10, 20, 30];
+    const svg = buildSparkline(pts, 150) as any;
+
+    expect(document.createElementNS).toHaveBeenCalledWith("http://www.w3.org/2000/svg", "svg");
+    expect(svg.tagName).toBe("svg");
+    expect(svg._getAttributes()).toMatchObject({
+      width: "80",
+      height: "20",
+      viewBox: "0 0 80 20",
+    });
+    expect(svg._getClasses()).toContain("result-sparkline");
+    expect(svg.style.top).toBe("150px");
+  });
+
+  it("appends a straight line when all points are equal (min === max)", () => {
+    const pts = [10, 10, 10];
+    const svg = buildSparkline(pts, 0) as any;
+
+    const children = svg._getChildren();
+    expect(children.length).toBe(1);
+
+    const line = children[0];
+    expect(line.tagName).toBe("line");
+    expect(line._getAttributes()).toMatchObject({
+      x1: "2",
+      y1: "10",
+      x2: "78",
+      y2: "10",
+      stroke: "var(--result)",
+      "stroke-width": "1.5",
+    });
+  });
+
+  it("appends a polyline and a circle for varying points", () => {
+    const pts = [10, 20, 30]; // min=10, max=30
+    const svg = buildSparkline(pts, 0) as any;
+
+    const children = svg._getChildren();
+    expect(children.length).toBe(2);
+
+    const polyline = children[0];
+    expect(polyline.tagName).toBe("polyline");
+    expect(polyline._getAttributes()).toMatchObject({
+      fill: "none",
+      stroke: "var(--result)",
+      "stroke-width": "1.5",
+      "stroke-linecap": "round",
+      "stroke-linejoin": "round",
+    });
+
+    // Check points calculation
+    const pointsStr = polyline._getAttributes().points;
+    expect(typeof pointsStr).toBe("string");
+    const points = pointsStr.split(" ");
+    expect(points.length).toBe(3);
+
+    // First point should be at x=2 (pad), y=18 (H-pad because value is min)
+    expect(points[0]).toBe("2.0,18.0");
+    // Middle point should be at x=40 (pad + W/2), y=10 (pad + H/2 because value is mid)
+    expect(points[1]).toBe("40.0,10.0");
+    // Last point should be at x=78 (W-pad), y=2 (pad because value is max)
+    expect(points[2]).toBe("78.0,2.0");
+
+    const circle = children[1];
+    expect(circle.tagName).toBe("circle");
+    expect(circle._getAttributes()).toMatchObject({
+      cx: "78.0",
+      cy: "2.0",
+      r: "2",
+      fill: "var(--result)",
+    });
+  });
+});

src/ui/sparkline.ts

@@ -0,0 +1,45 @@
+export function buildSparkline(pts: number[], top: number): SVGSVGElement {
+  const NS = "http://www.w3.org/2000/svg";
+  const W = 80, H = 20, pad = 2;
+  const svg = document.createElementNS(NS, "svg") as SVGSVGElement;
+  svg.setAttribute("width", String(W));
+  svg.setAttribute("height", String(H));
+  svg.setAttribute("viewBox", `0 0 ${W} ${H}`);
+  svg.classList.add("result-sparkline");
+  svg.style.top = `${top}px`;
+  const min = Math.min(...pts), max = Math.max(...pts);
+  if (min === max) {
+    const line = document.createElementNS(NS, "line");
+    line.setAttribute("x1", String(pad));
+    line.setAttribute("y1", String(H / 2));
+    line.setAttribute("x2", String(W - pad));
+    line.setAttribute("y2", String(H / 2));
+    line.setAttribute("stroke", "var(--result)");
+    line.setAttribute("stroke-width", "1.5");
+    svg.appendChild(line);
+  } else {
+    const coords = pts.map((v, i) => {
+      const x = pad + (i / (pts.length - 1)) * (W - 2 * pad);
+      const y = pad + (1 - (v - min) / (max - min)) * (H - 2 * pad);
+      return `${x.toFixed(1)},${y.toFixed(1)}`;
+    }).join(" ");
+    const poly = document.createElementNS(NS, "polyline");
+    poly.setAttribute("points", coords);
+    poly.setAttribute("fill", "none");
+    poly.setAttribute("stroke", "var(--result)");
+    poly.setAttribute("stroke-width", "1.5");
+    poly.setAttribute("stroke-linecap", "round");
+    poly.setAttribute("stroke-linejoin", "round");
+    svg.appendChild(poly);
+    const last = pts[pts.length - 1];
+    const cx = (W - pad).toFixed(1);
+    const cy = (pad + (1 - (last - min) / (max - min)) * (H - 2 * pad)).toFixed(1);
+    const dot = document.createElementNS(NS, "circle");
+    dot.setAttribute("cx", cx);
+    dot.setAttribute("cy", cy);
+    dot.setAttribute("r", "2");
+    dot.setAttribute("fill", "var(--result)");
+    svg.appendChild(dot);
+  }
+  return svg;
+}

src/updater.test.ts

@@ -0,0 +1,81 @@
+import { logger } from "./logger";
+import { describe, it, expect, vi, beforeEach } from 'vitest';
+import { checkForUpdate } from './updater';
+import * as storage from './storage';
+import type { Update } from '@tauri-apps/plugin-updater';
+
+vi.mock('./storage', () => ({
+  isTauri: vi.fn(),
+}));
+
+vi.mock('@tauri-apps/plugin-updater', () => ({
+  check: vi.fn(),
+}));
+
+vi.mock('@tauri-apps/api/app', () => ({
+  getVersion: vi.fn(),
+}));
+
+vi.mock('@tauri-apps/plugin-process', () => ({
+  relaunch: vi.fn(),
+}));
+
+describe('checkForUpdate', () => {
+  beforeEach(() => {
+    vi.resetAllMocks();
+    vi.spyOn(logger, 'info').mockImplementation(() => {});
+    vi.spyOn(logger, 'warn').mockImplementation(() => {});
+  });
+
+  it('should return null if not in Tauri', async () => {
+    vi.mocked(storage.isTauri).mockReturnValue(false);
+    const result = await checkForUpdate();
+    expect(result).toBeNull();
+  });
+
+  it('should return "error" if dynamic import or check throws', async () => {
+    vi.mocked(storage.isTauri).mockReturnValue(true);
+    const { check } = await import('@tauri-apps/plugin-updater');
+    vi.mocked(check).mockRejectedValue(new Error('Network error'));
+
+    const result = await checkForUpdate();
+    expect(result).toBe('error');
+    expect(logger.warn).toHaveBeenCalledWith('update check failed', expect.any(Error));
+  });
+
+  it('should return null if no update is available', async () => {
+    vi.mocked(storage.isTauri).mockReturnValue(true);
+    const { check } = await import('@tauri-apps/plugin-updater');
+    const { getVersion } = await import('@tauri-apps/api/app');
+
+    vi.mocked(check).mockResolvedValue(null);
+    vi.mocked(getVersion).mockResolvedValue('1.0.0');
+
+    const result = await checkForUpdate();
+    expect(result).toBeNull();
+    expect(logger.info).toHaveBeenCalledWith("no update: running 1.0.0, that's the latest published release");
+  });
+
+  it('should return an update object if an update is available', async () => {
+    vi.mocked(storage.isTauri).mockReturnValue(true);
+    const { check } = await import('@tauri-apps/plugin-updater');
+
+    const mockUpdate = {
+      version: '1.1.0',
+      currentVersion: '1.0.0',
+      downloadAndInstall: vi.fn().mockResolvedValue(undefined),
+    } as unknown as Update;
+    vi.mocked(check).mockResolvedValue(mockUpdate);
+
+    const result = await checkForUpdate();
+    expect(result).not.toBeNull();
+    if (result !== 'error' && result !== null) {
+      expect(result.version).toBe('1.1.0');
+
+      const { relaunch } = await import('@tauri-apps/plugin-process');
+      await result.install();
+      expect(mockUpdate.downloadAndInstall).toHaveBeenCalled();
+      expect(relaunch).toHaveBeenCalled();
+    }
+  });
+});

src/updater.ts

@@ -1,6 +1,7 @@
+import { logger } from "./logger";
 import { isTauri } from "./storage";
 
-export interface AvailableUpdate {
+interface AvailableUpdate {
   version: string;
   install(): Promise<void>;
 }
@@ -19,10 +20,10 @@ export async function checkForUpdate(): Promise<AvailableUpdate | null | "error"
       // visible in devtools console — the fastest way to tell "already on
       // the latest published release" apart from "the check silently failed"
       const { getVersion } = await import("@tauri-apps/api/app");
-      console.info(`no update: running ${await getVersion()}, that's the latest published release`);
+      logger.info(`no update: running ${await getVersion()}, that's the latest published release`);
       return null;
     }
-    console.info(`update available: ${update.currentVersion} -> ${update.version}`);
+    logger.info(`update available: ${update.currentVersion} -> ${update.version}`);
     return {
       version: update.version,
       async install() {
@@ -32,7 +33,7 @@ export async function checkForUpdate(): Promise<AvailableUpdate | null | "error"
       },
     };
   } catch (e) {
-    console.warn("update check failed", e);
+    logger.warn("update check failed", e);
     return "error";
   }
 }

src/workspace.test.ts

@@ -44,6 +44,19 @@ describe("Workspace exports", () => {
   });
 });
 
+describe("Workspace error handling", () => {
+  it("cleans up the resolving set if evaluation throws an unexpected error", () => {
+    const { ws, engine } = makeWorkspace({
+      a: { title: "A", text: "1 + 1" },
+    });
+    vi.spyOn(engine, "evaluateDocument").mockImplementation(() => {
+      throw new Error("mocked crash");
+    });
+    expect(() => ws.evaluateSheet("a", "1 + 1")).toThrowError("mocked crash");
+    expect((ws as any).resolving.has("a")).toBe(false);
+  });
+});
+
 describe("Workspace invalidation", () => {
   it("invalidating a sheet also invalidates its dependents, not unrelated sheets", () => {
     const { ws, store } = makeWorkspace({

src/workspace.ts

@@ -15,6 +15,7 @@ interface SheetExports {
   vars: Map<string, Value>;
   total: Value | null;
   last: Value | null;
+  results: LineResult[];
 }
 
 const XREF_SCAN_RE = /@(?:\[([^\]]+)\]|([\p{L}_][\p{L}\d_]*))\./gu;
@@ -25,29 +26,41 @@ function escapeRegExp(s: string): string {
 
 export class Workspace {
   private cache = new Map<string, SheetExports>();
-  private resolving: string[] = [];
+  private resolving: Set<string> = new Set();
+  private parsedRefsCache = new Map<string, { text: string; refs: string[] }>();
+  private titleCache: Map<string, SheetSource> | null = null;
 
   constructor(private engine: SumEngine, private sheets: () => SheetSource[]) {}
 
-  /** Evaluate a sheet as the user's active/open document — refs resolve live. */
+  private doEvaluate(sheetId: string, text: string): LineResult[] {
-  evaluateSheet(sheetId: string, text: string): LineResult[] {
+    this.resolving.add(sheetId);
-    this.resolving.push(sheetId);
     try {
       return this.engine.evaluateDocument(text, (sheet, key) => this.resolveXRef(sheet, key));
     } finally {
-      this.resolving.pop();
+      this.resolving.delete(sheetId);
     }
   }
 
+  /** Evaluate a sheet as the user's active/open document — refs resolve live. */
+  evaluateSheet(sheetId: string, text: string): LineResult[] {
+    return this.doEvaluate(sheetId, text);
+  }
+
+  getCachedResults(sheet: SheetSource): LineResult[] {
+    return this.exportsFor(sheet).results;
+  }
+
   /** Drop cached exports for a sheet and everything that transitively depends on it. */
   invalidate(sheetId: string): void {
+    this.titleCache = null;
     const dirty = new Set<string>([sheetId]);
+    const sheetsList = this.sheets();
     let changed = true;
     while (changed) {
       changed = false;
-      for (const s of this.sheets()) {
+      for (const s of sheetsList) {
         if (dirty.has(s.id)) continue;
-        for (const title of this.referencedTitles(s.text)) {
+        for (const title of this.referencedTitles(s.text, s.id)) {
           const target = this.findSheetByTitle(title);
           if (target && dirty.has(target.id)) {
             dirty.add(s.id);
@@ -61,7 +74,9 @@ export class Workspace {
   }
 
   invalidateAll(): void {
+    this.titleCache = null;
     this.cache.clear();
+    this.parsedRefsCache.clear();
   }
 
   /**
@@ -83,21 +98,37 @@ export class Workspace {
     return out;
   }
 
-  private referencedTitles(text: string): string[] {
+  private referencedTitles(text: string, id?: string): string[] {
+    if (id) {
+      const cached = this.parsedRefsCache.get(id);
+      if (cached && cached.text === text) return cached.refs;
+    }
     const out: string[] = [];
     for (const m of text.matchAll(XREF_SCAN_RE)) out.push((m[1] ?? m[2]).trim());
+    if (id) {
+      this.parsedRefsCache.set(id, { text, refs: out });
+    }
     return out;
   }
 
   private findSheetByTitle(title: string): SheetSource | undefined {
     const needle = title.trim().toLowerCase();
-    return this.sheets().find((s) => s.title.trim().toLowerCase() === needle);
+    if (this.titleCache === null) {
+      this.titleCache = new Map();
+      for (const s of this.sheets()) {
+        const key = s.title.trim().toLowerCase();
+        if (!this.titleCache.has(key)) {
+          this.titleCache.set(key, s);
+        }
+      }
+    }
+    return this.titleCache.get(needle);
   }
 
   private resolveXRef(sheetTitle: string, key: string): XRefResolution {
     const target = this.findSheetByTitle(sheetTitle);
     if (!target) return { ok: false, reason: `sheet "${sheetTitle}" not found` };
-    if (this.resolving.includes(target.id)) {
+    if (this.resolving.has(target.id)) {
       return { ok: false, reason: "circular reference" };
     }
     const exports = this.exportsFor(target);
@@ -119,13 +150,7 @@ export class Workspace {
   private exportsFor(sheet: SheetSource): SheetExports {
     const cached = this.cache.get(sheet.id);
     if (cached) return cached;
-    this.resolving.push(sheet.id);
+    const results = this.doEvaluate(sheet.id, sheet.text);
-    let results: LineResult[];
-    try {
-      results = this.engine.evaluateDocument(sheet.text, (s, k) => this.resolveXRef(s, k));
-    } finally {
-      this.resolving.pop();
-    }
     const vars = new Map<string, Value>();
     for (const r of results) {
       if (r.assign && r.value) vars.set(r.assign, r.value);
@@ -137,7 +162,7 @@ export class Workspace {
         break;
       }
     }
-    const exports: SheetExports = { vars, total: this.engine.totalValueOf(results), last };
+    const exports: SheetExports = { vars, total: this.engine.totalValueOf(results), last, results };
     // A cycle-interrupted pass produces incomplete/wrong exports (dropped
     // assignments, missing total) — don't let it poison the cache. Re-evaluate
     // fresh on every query until the cycle is actually broken by an edit.