[ide-mode] Keep track of recently-opened files and send them to the CLI (#4463)

1 files changed, 211 insertions, 0 deletions

diff --git a/packages/vscode-ide-companion/src/recent-files-manager.test.ts b/packages/vscode-ide-companion/src/recent-files-manager.test.ts
new file mode 100644
index 00000000..27742ed2
--- /dev/null
+++ b/packages/vscode-ide-companion/src/recent-files-manager.test.ts
@@ -0,0 +1,211 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+import * as vscode from 'vscode';
+import {
+  RecentFilesManager,
+  MAX_FILES,
+  MAX_FILE_AGE_MINUTES,
+} from './recent-files-manager.js';
+
+vi.mock('vscode', () => ({
+  EventEmitter: vi.fn(() => ({
+    event: vi.fn(),
+    fire: vi.fn(),
+    dispose: vi.fn(),
+  })),
+  window: {
+    onDidChangeActiveTextEditor: vi.fn(),
+  },
+  workspace: {
+    onDidDeleteFiles: vi.fn(),
+    onDidCloseTextDocument: vi.fn(),
+    onDidRenameFiles: vi.fn(),
+  },
+  Uri: {
+    file: (path: string) => ({
+      fsPath: path,
+    }),
+  },
+}));
+
+describe('RecentFilesManager', () => {
+  let context: vscode.ExtensionContext;
+
+  beforeEach(() => {
+    context = {
+      subscriptions: [],
+    } as unknown as vscode.ExtensionContext;
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('adds a file to the list', () => {
+    const manager = new RecentFilesManager(context);
+    const uri = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri);
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file1.txt');
+  });
+
+  it('moves an existing file to the top', () => {
+    const manager = new RecentFilesManager(context);
+    const uri1 = vscode.Uri.file('/test/file1.txt');
+    const uri2 = vscode.Uri.file('/test/file2.txt');
+    manager.add(uri1);
+    manager.add(uri2);
+    manager.add(uri1);
+    expect(manager.recentFiles).toHaveLength(2);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file1.txt');
+  });
+
+  it('does not exceed the max number of files', () => {
+    const manager = new RecentFilesManager(context);
+    for (let i = 0; i < MAX_FILES + 5; i++) {
+      const uri = vscode.Uri.file(`/test/file${i}.txt`);
+      manager.add(uri);
+    }
+    expect(manager.recentFiles).toHaveLength(MAX_FILES);
+    expect(manager.recentFiles[0].filePath).toBe(
+      `/test/file${MAX_FILES + 4}.txt`,
+    );
+    expect(manager.recentFiles[MAX_FILES - 1].filePath).toBe(`/test/file5.txt`);
+  });
+
+  it('fires onDidChange when a file is added', () => {
+    const manager = new RecentFilesManager(context);
+    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
+    const uri = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri);
+    expect(spy).toHaveBeenCalled();
+  });
+
+  it('removes a file when it is closed', () => {
+    const manager = new RecentFilesManager(context);
+    const uri = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri);
+    expect(manager.recentFiles).toHaveLength(1);
+
+    // Simulate closing the file
+    const closeHandler = vi.mocked(vscode.workspace.onDidCloseTextDocument).mock
+      .calls[0][0];
+    closeHandler({ uri } as vscode.TextDocument);
+
+    expect(manager.recentFiles).toHaveLength(0);
+  });
+
+  it('fires onDidChange when a file is removed', () => {
+    const manager = new RecentFilesManager(context);
+    const uri = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri);
+
+    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
+    const closeHandler = vi.mocked(vscode.workspace.onDidCloseTextDocument).mock
+      .calls[0][0];
+    closeHandler({ uri } as vscode.TextDocument);
+
+    expect(spy).toHaveBeenCalled();
+  });
+
+  it('removes a file when it is deleted', () => {
+    const manager = new RecentFilesManager(context);
+    const uri1 = vscode.Uri.file('/test/file1.txt');
+    const uri2 = vscode.Uri.file('/test/file2.txt');
+    manager.add(uri1);
+    manager.add(uri2);
+    expect(manager.recentFiles).toHaveLength(2);
+
+    // Simulate deleting a file
+    const deleteHandler = vi.mocked(vscode.workspace.onDidDeleteFiles).mock
+      .calls[0][0];
+    deleteHandler({ files: [uri1] });
+
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file2.txt');
+  });
+
+  it('fires onDidChange when a file is deleted', () => {
+    const manager = new RecentFilesManager(context);
+    const uri = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri);
+
+    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
+    const deleteHandler = vi.mocked(vscode.workspace.onDidDeleteFiles).mock
+      .calls[0][0];
+    deleteHandler({ files: [uri] });
+
+    expect(spy).toHaveBeenCalled();
+  });
+
+  it('removes multiple files when they are deleted', () => {
+    const manager = new RecentFilesManager(context);
+    const uri1 = vscode.Uri.file('/test/file1.txt');
+    const uri2 = vscode.Uri.file('/test/file2.txt');
+    const uri3 = vscode.Uri.file('/test/file3.txt');
+    manager.add(uri1);
+    manager.add(uri2);
+    manager.add(uri3);
+    expect(manager.recentFiles).toHaveLength(3);
+
+    // Simulate deleting multiple files
+    const deleteHandler = vi.mocked(vscode.workspace.onDidDeleteFiles).mock
+      .calls[0][0];
+    deleteHandler({ files: [uri1, uri3] });
+
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file2.txt');
+  });
+
+  it('prunes files older than the max age', () => {
+    vi.useFakeTimers();
+
+    const manager = new RecentFilesManager(context);
+    const uri1 = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri1);
+
+    // Advance time by more than the max age
+    const twoMinutesMs = (MAX_FILE_AGE_MINUTES + 1) * 60 * 1000;
+    vi.advanceTimersByTime(twoMinutesMs);
+
+    const uri2 = vscode.Uri.file('/test/file2.txt');
+    manager.add(uri2);
+
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file2.txt');
+
+    vi.useRealTimers();
+  });
+
+  it('fires onDidChange only once when adding an existing file', () => {
+    const manager = new RecentFilesManager(context);
+    const uri = vscode.Uri.file('/test/file1.txt');
+    manager.add(uri);
+
+    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
+    manager.add(uri);
+    expect(spy).toHaveBeenCalledTimes(1);
+  });
+
+  it('updates the file when it is renamed', () => {
+    const manager = new RecentFilesManager(context);
+    const oldUri = vscode.Uri.file('/test/file1.txt');
+    const newUri = vscode.Uri.file('/test/file2.txt');
+    manager.add(oldUri);
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file1.txt');
+
+    // Simulate renaming the file
+    const renameHandler = vi.mocked(vscode.workspace.onDidRenameFiles).mock
+      .calls[0][0];
+    renameHandler({ files: [{ oldUri, newUri }] });
+
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file2.txt');
+  });
+});