test: Add tests for initSearch function

Added unit tests for the previously untested initSearch function
in src/ui/search.ts. A manual DOM mock was implemented to verify
UI behaviors such as opening, closing, debouncing inputs, rendering
results, and reacting to user actions without relying on jsdom.

Co-authored-by: Horizontal42 <75383519+Horizontal42@users.noreply.github.com>

src/ui/search.test.ts

@@ -1,6 +1,6 @@
-import { describe, it, expect, vi } from "vitest";
+import { describe, it, expect, vi, beforeEach, afterEach } from "vitest";
 import { SumEngine } from "../engine";
-import { parseResultQuery, searchAllSheets, SearchDeps, SearchDoc } from "./search";
+import { initSearch, parseResultQuery, searchAllSheets, SearchDeps, SearchDoc } from "./search";
 import { Workspace } from "../workspace";
 import Decimal from "decimal.js";
 
@@ -241,3 +241,200 @@ describe("searchAllSheets", () => {
     });
   });
 });
+
+describe("initSearch", () => {
+  class MockElement {
+    className: string = "";
+    textContent: string = "";
+    value: string = "";
+    classList = {
+      add: vi.fn(),
+      remove: vi.fn(),
+    };
+    children: MockElement[] = [];
+    listeners: Record<string, Function[]> = {};
+
+    replaceChildren() {
+      this.children = [];
+    }
+
+    appendChild(child: MockElement) {
+      if (child.isFragment) {
+        this.children.push(...child.children);
+      } else {
+        this.children.push(child);
+      }
+    }
+
+    append(...children: MockElement[]) {
+      this.children.push(...children);
+    }
+
+    addEventListener(event: string, handler: Function) {
+      if (!this.listeners[event]) this.listeners[event] = [];
+      this.listeners[event].push(handler);
+    }
+
+    dispatchEvent(event: any) {
+      const handlers = this.listeners[event.type] || [];
+      for (const h of handlers) h(event);
+    }
+
+    focus = vi.fn();
+
+    click() {
+      this.dispatchEvent({ type: "click" });
+    }
+
+    querySelector(sel: string): MockElement | undefined {
+      if (sel === ".search-item") {
+        return this.children.find(c => c.className === "search-item");
+      }
+      return undefined;
+    }
+
+    isFragment = false;
+  }
+
+  let elements: Record<string, MockElement>;
+
+  beforeEach(() => {
+    elements = {
+      "#search-overlay": new MockElement(),
+      "#search-input": new MockElement(),
+      "#search-results": new MockElement(),
+    };
+
+    vi.stubGlobal("document", {
+      querySelector: vi.fn((sel: string) => elements[sel]),
+      createElement: vi.fn((tag: string) => new MockElement()),
+      createDocumentFragment: vi.fn(() => {
+        const frag = new MockElement();
+        frag.isFragment = true;
+        return frag;
+      }),
+    });
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    vi.useRealTimers();
+  });
+
+  it("opens search and focuses input", () => {
+    const deps = { t: vi.fn(), onOpen: vi.fn() } as unknown as SearchDeps;
+    const ctrl = initSearch(deps);
+
+    ctrl.open();
+
+    expect(elements["#search-overlay"].classList.remove).toHaveBeenCalledWith("hidden");
+    expect(elements["#search-input"].value).toBe("");
+    expect(elements["#search-input"].focus).toHaveBeenCalled();
+    expect(elements["#search-results"].children).toHaveLength(0);
+  });
+
+  it("closes search on Escape key", () => {
+    const deps = { t: vi.fn(), onOpen: vi.fn() } as unknown as SearchDeps;
+    initSearch(deps);
+
+    elements["#search-input"].dispatchEvent({ type: "keydown", key: "Escape" });
+
+    expect(elements["#search-overlay"].classList.add).toHaveBeenCalledWith("hidden");
+  });
+
+  it("closes search on clicking overlay", () => {
+    const deps = { t: vi.fn(), onOpen: vi.fn() } as unknown as SearchDeps;
+    initSearch(deps);
+
+    elements["#search-overlay"].dispatchEvent({ type: "mousedown", target: elements["#search-overlay"] });
+
+    expect(elements["#search-overlay"].classList.add).toHaveBeenCalledWith("hidden");
+  });
+
+  it("renders empty state", () => {
+    const deps = {
+      t: vi.fn().mockReturnValue("No results"),
+      docs: () => [],
+    } as unknown as SearchDeps;
+    initSearch(deps);
+
+    elements["#search-input"].value = "test query";
+    elements["#search-input"].dispatchEvent({ type: "input" });
+
+    vi.runAllTimers();
+
+    const results = elements["#search-results"];
+    expect(results.children).toHaveLength(1);
+    expect(results.children[0].className).toBe("search-empty");
+    expect(results.children[0].textContent).toBe("No results");
+  });
+
+  it("renders search hits and opens them on click", () => {
+    const deps = {
+      docs: () => [{ id: "doc1", title: "Doc 1", text: "test match" }],
+      onOpen: vi.fn(),
+      engine: new SumEngine(),
+    } as unknown as SearchDeps;
+    initSearch(deps);
+
+    elements["#search-input"].value = "test";
+    elements["#search-input"].dispatchEvent({ type: "input" });
+
+    vi.runAllTimers();
+
+    const results = elements["#search-results"];
+    expect(results.children).toHaveLength(1);
+
+    const item = results.children[0];
+    expect(item.className).toBe("search-item");
+    expect(item.children).toHaveLength(2);
+    expect(item.children[0].className).toBe("doc");
+    expect(item.children[0].textContent).toBe("Doc 1");
+    expect(item.children[1].className).toBe("line");
+    expect(item.children[1].textContent).toBe("test match");
+
+    item.click();
+    expect(deps.onOpen).toHaveBeenCalledWith("doc1", 1);
+    expect(elements["#search-overlay"].classList.add).toHaveBeenCalledWith("hidden");
+  });
+
+  it("opens first result on Enter key", () => {
+    const deps = {
+      docs: () => [{ id: "doc1", title: "Doc 1", text: "test match" }],
+      onOpen: vi.fn(),
+      engine: new SumEngine(),
+    } as unknown as SearchDeps;
+    initSearch(deps);
+
+    elements["#search-input"].value = "test";
+    elements["#search-input"].dispatchEvent({ type: "input" });
+
+    vi.runAllTimers();
+
+    elements["#search-input"].dispatchEvent({ type: "keydown", key: "Enter" });
+
+    expect(deps.onOpen).toHaveBeenCalledWith("doc1", 1);
+  });
+
+  it("debounces search inputs", () => {
+    const deps = {
+      docs: vi.fn().mockReturnValue([]),
+      t: vi.fn(),
+    } as unknown as SearchDeps;
+    initSearch(deps);
+
+    elements["#search-input"].value = "t";
+    elements["#search-input"].dispatchEvent({ type: "input" });
+    elements["#search-input"].value = "te";
+    elements["#search-input"].dispatchEvent({ type: "input" });
+    elements["#search-input"].value = "tes";
+    elements["#search-input"].dispatchEvent({ type: "input" });
+
+    expect(deps.docs).not.toHaveBeenCalled();
+
+    vi.advanceTimersByTime(150);
+
+    expect(deps.docs).toHaveBeenCalledTimes(1);
+  });
+});