feat: convert file manager into a plugin

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

@@ -0,0 +1,92 @@
+import { describe, it, expect, vi } from "vitest";
+import { act, renderHook } from "@testing-library/react";
+import { useDragAndDrop } from "../../../src/frontend/hooks/useDragAndDrop.js";
+
+function makeEntry(name: string, isDirectory: boolean) {
+  return { name, isDirectory, isFile: !isDirectory } as FileSystemEntry;
+}
+
+function makeDropEvent(entries: FileSystemEntry[], files: File[] = []) {
+  const items = entries.map((entry) => ({
+    webkitGetAsEntry: () => entry,
+  }));
+
+  const dataTransfer = {
+    items,
+    files: Object.assign(files, { item: (i: number) => files[i] }),
+  };
+
+  return {
+    preventDefault: vi.fn(),
+    stopPropagation: vi.fn(),
+    dataTransfer,
+  } as unknown as React.DragEvent;
+}
+
+describe("useDragAndDrop", () => {
+  it("hands directory entries to onItemsDropped", () => {
+    const onItemsDropped = vi.fn();
+    const onFilesDropped = vi.fn();
+    const { result } = renderHook(() =>
+      useDragAndDrop({ onFilesDropped, onItemsDropped }),
+    );
+
+    const dir = makeEntry("myfolder", true);
+    act(() => result.current.dragHandlers.onDrop(makeDropEvent([dir])));
+
+    expect(onItemsDropped).toHaveBeenCalledWith([dir]);
+    expect(onFilesDropped).not.toHaveBeenCalled();
+  });
+
+  it("reads entries before state updates clear dataTransfer", () => {
+    const onItemsDropped = vi.fn();
+    const { result } = renderHook(() =>
+      useDragAndDrop({ onFilesDropped: vi.fn(), onItemsDropped }),
+    );
+
+    const dir = makeEntry("myfolder", true);
+    const event = makeDropEvent([dir]);
+
+    // Mimic the browser neutering dataTransfer once the handler unwinds.
+    act(() => {
+      result.current.dragHandlers.onDrop(event);
+      (event.dataTransfer as unknown as { items: unknown[] }).items = [];
+    });
+
+    expect(onItemsDropped).toHaveBeenCalledWith([dir]);
+  });
+
+  it("falls back to plain file upload when no directory is dropped", () => {
+    const onFilesDropped = vi.fn();
+    const onItemsDropped = vi.fn();
+    const { result } = renderHook(() =>
+      useDragAndDrop({ onFilesDropped, onItemsDropped }),
+    );
+
+    const file = new File(["hi"], "a.txt");
+    act(() =>
+      result.current.dragHandlers.onDrop(
+        makeDropEvent([makeEntry("a.txt", false)], [file]),
+      ),
+    );
+
+    expect(onItemsDropped).not.toHaveBeenCalled();
+    expect(onFilesDropped).toHaveBeenCalled();
+  });
+
+  it("rejects files over the size limit", () => {
+    const onError = vi.fn();
+    const onFilesDropped = vi.fn();
+    const { result } = renderHook(() =>
+      useDragAndDrop({ onFilesDropped, onError, maxFileSize: 1 }),
+    );
+
+    const big = new File(["x"], "big.bin");
+    Object.defineProperty(big, "size", { value: 5 * 1024 * 1024 });
+
+    act(() => result.current.dragHandlers.onDrop(makeDropEvent([], [big])));
+
+    expect(onFilesDropped).not.toHaveBeenCalled();
+    expect(onError).toHaveBeenCalled();
+  });
+});