feat: convert file manager into a plugin

plugins/file-manager/tests/frontend/hooks/useFileSelection.test.ts

@@ -0,0 +1,69 @@
+import { describe, it, expect } from "vitest";
+import { act, renderHook } from "@testing-library/react";
+import { useFileSelection } from "../../../src/frontend/hooks/useFileSelection.js";
+
+type FileItem = {
+  name: string;
+  type: "file" | "directory" | "link";
+  path: string;
+};
+
+const f = (name: string): FileItem => ({
+  name,
+  type: "file",
+  path: `/dir/${name}`,
+});
+
+describe("useFileSelection", () => {
+  it("single-selects, replacing prior selection", () => {
+    const { result } = renderHook(() => useFileSelection());
+    act(() => result.current.selectFile(f("a")));
+    act(() => result.current.selectFile(f("b")));
+    expect(result.current.selectedFiles.map((x) => x.name)).toEqual(["b"]);
+    expect(result.current.getSelectedCount()).toBe(1);
+  });
+
+  it("multi-selects and toggles off on repeat", () => {
+    const { result } = renderHook(() => useFileSelection());
+    act(() => result.current.selectFile(f("a"), true));
+    act(() => result.current.selectFile(f("b"), true));
+    expect(result.current.getSelectedCount()).toBe(2);
+    act(() => result.current.selectFile(f("a"), true));
+    expect(result.current.selectedFiles.map((x) => x.name)).toEqual(["b"]);
+  });
+
+  it("reports isSelected by path", () => {
+    const { result } = renderHook(() => useFileSelection());
+    act(() => result.current.selectFile(f("a")));
+    expect(result.current.isSelected(f("a"))).toBe(true);
+    expect(result.current.isSelected(f("z"))).toBe(false);
+  });
+
+  it("selects a contiguous range regardless of direction", () => {
+    const { result } = renderHook(() => useFileSelection());
+    const files = [f("a"), f("b"), f("c"), f("d")];
+    act(() => result.current.selectRange(files, files[3], files[1]));
+    expect(result.current.selectedFiles.map((x) => x.name)).toEqual([
+      "b",
+      "c",
+      "d",
+    ]);
+  });
+
+  it("selects all and clears", () => {
+    const { result } = renderHook(() => useFileSelection());
+    const files = [f("a"), f("b")];
+    act(() => result.current.selectAll(files));
+    expect(result.current.getSelectedCount()).toBe(2);
+    act(() => result.current.clearSelection());
+    expect(result.current.getSelectedCount()).toBe(0);
+  });
+
+  it("toggleSelection adds then removes", () => {
+    const { result } = renderHook(() => useFileSelection());
+    act(() => result.current.toggleSelection(f("a")));
+    expect(result.current.isSelected(f("a"))).toBe(true);
+    act(() => result.current.toggleSelection(f("a")));
+    expect(result.current.isSelected(f("a"))).toBe(false);
+  });
+});