Minor refactoring of VS Code companion extension code (#4761)

8 files changed, 244 insertions, 115 deletions

diff --git a/.vscode/launch.json b/.vscode/launch.json
index 605a464d..9b9d150d 100644
--- a/.vscode/launch.json
+++ b/.vscode/launch.json
@@ -31,6 +31,18 @@
       }
     },
     {
+      "name": "Launch Companion VS Code Extension",
+      "type": "extensionHost",
+      "request": "launch",
+      "args": [
+        "--extensionDevelopmentPath=${workspaceFolder}/packages/vscode-ide-companion"
+      ],
+      "outFiles": [
+        "${workspaceFolder}/packages/vscode-ide-companion/dist/**/*.js"
+      ],
+      "preLaunchTask": "npm: build: vscode-ide-companion"
+    },
+    {
       "name": "Attach",
       "port": 9229,
       "request": "attach",
diff --git a/.vscode/tasks.json b/.vscode/tasks.json
index 1ff9a62f..58709bc9 100644
--- a/.vscode/tasks.json
+++ b/.vscode/tasks.json
@@ -11,6 +11,15 @@
       "problemMatcher": [],
       "label": "npm: build",
       "detail": "scripts/build.sh"
+    },
+    {
+      "type": "npm",
+      "script": "build",
+      "path": "packages/vscode-ide-companion",
+      "group": "build",
+      "problemMatcher": [],
+      "label": "npm: build: vscode-ide-companion",
+      "detail": "npm run build -w packages/vscode-ide-companion"
     }
   ]
 }
diff --git a/packages/vscode-ide-companion/README.md b/packages/vscode-ide-companion/README.md
index bd7026ee..1b96d7f3 100644
--- a/packages/vscode-ide-companion/README.md
+++ b/packages/vscode-ide-companion/README.md
@@ -13,7 +13,7 @@ The Gemini CLI Companion extension seamlessly integrates [Gemini CLI](https://gi
 To use this extension, you'll need:
 
 - VS Code version 1.101.0 or newer
-- Gemini CLI (installed separately) and running within the VS Code integrated terminal
+- Gemini CLI (installed separately) running within the VS Code integrated terminal
 
 # Terms of Service and Privacy Notice
 
diff --git a/packages/vscode-ide-companion/src/extension.ts b/packages/vscode-ide-companion/src/extension.ts
index 71d3138f..912b9b8f 100644
--- a/packages/vscode-ide-companion/src/extension.ts
+++ b/packages/vscode-ide-companion/src/extension.ts
@@ -6,30 +6,38 @@
 
 import * as vscode from 'vscode';
 import { IDEServer } from './ide-server';
+import { createLogger } from './utils/logger';
 
 let ideServer: IDEServer;
 let logger: vscode.OutputChannel;
+let log: (message: string) => void = () => {};
 
 export async function activate(context: vscode.ExtensionContext) {
   logger = vscode.window.createOutputChannel('Gemini CLI IDE Companion');
-  logger.appendLine('Starting Gemini CLI IDE Companion server...');
-  ideServer = new IDEServer(logger);
+  log = createLogger(context, logger);
+
+  log('Extension activated');
+  ideServer = new IDEServer(log);
   try {
     await ideServer.start(context);
   } catch (err) {
     const message = err instanceof Error ? err.message : String(err);
-    logger.appendLine(`Failed to start IDE server: ${message}`);
+    log(`Failed to start IDE server: ${message}`);
   }
 }
 
-export function deactivate() {
-  if (ideServer) {
-    logger.appendLine('Deactivating Gemini CLI IDE Companion...');
-    return ideServer.stop().finally(() => {
+export async function deactivate(): Promise<void> {
+  log('Extension deactivated');
+  try {
+    if (ideServer) {
+      await ideServer.stop();
+    }
+  } catch (err) {
+    const message = err instanceof Error ? err.message : String(err);
+    log(`Failed to stop IDE server during deactivation: ${message}`);
+  } finally {
+    if (logger) {
       logger.dispose();
-    });
-  }
-  if (logger) {
-    logger.dispose();
+    }
   }
 }
diff --git a/packages/vscode-ide-companion/src/ide-server.ts b/packages/vscode-ide-companion/src/ide-server.ts
index 9111f349..75828485 100644
--- a/packages/vscode-ide-companion/src/ide-server.ts
+++ b/packages/vscode-ide-companion/src/ide-server.ts
@@ -21,30 +21,41 @@ const IDE_SERVER_PORT_ENV_VAR = 'GEMINI_CLI_IDE_SERVER_PORT';
 
 function sendOpenFilesChangedNotification(
   transport: StreamableHTTPServerTransport,
-  logger: vscode.OutputChannel,
+  log: (message: string) => void,
   recentFilesManager: RecentFilesManager,
 ) {
   const editor = vscode.window.activeTextEditor;
-  const filePath = editor ? editor.document.uri.fsPath : '';
-  logger.appendLine(`Sending active file changed notification: ${filePath}`);
+  const filePath =
+    editor && editor.document.uri.scheme === 'file'
+      ? editor.document.uri.fsPath
+      : '';
   const notification: JSONRPCNotification = {
     jsonrpc: '2.0',
     method: 'ide/openFilesChanged',
     params: {
       activeFile: filePath,
-      recentOpenFiles: recentFilesManager.recentFiles,
+      recentOpenFiles: recentFilesManager.recentFiles.filter(
+        (file) => file.filePath !== filePath,
+      ),
     },
   };
+  log(
+    `Sending active file changed notification: ${JSON.stringify(
+      notification,
+      null,
+      2,
+    )}`,
+  );
   transport.send(notification);
 }
 
 export class IDEServer {
   private server: HTTPServer | undefined;
   private context: vscode.ExtensionContext | undefined;
-  private logger: vscode.OutputChannel;
+  private log: (message: string) => void;
 
-  constructor(logger: vscode.OutputChannel) {
-    this.logger = logger;
+  constructor(log: (message: string) => void) {
+    this.log = log;
   }
 
   async start(context: vscode.ExtensionContext) {
@@ -62,7 +73,7 @@ export class IDEServer {
       for (const transport of Object.values(transports)) {
         sendOpenFilesChangedNotification(
           transport,
-          this.logger,
+          this.log.bind(this),
           recentFilesManager,
         );
       }
@@ -81,7 +92,7 @@ export class IDEServer {
         transport = new StreamableHTTPServerTransport({
           sessionIdGenerator: () => randomUUID(),
           onsessioninitialized: (newSessionId) => {
-            this.logger.appendLine(`New session initialized: ${newSessionId}`);
+            this.log(`New session initialized: ${newSessionId}`);
             transports[newSessionId] = transport;
           },
         });
@@ -90,26 +101,24 @@ export class IDEServer {
           try {
             transport.send({ jsonrpc: '2.0', method: 'ping' });
           } catch (e) {
-            // If sending a ping fails, the connection is likely broken.
-            // Log the error and clear the interval to prevent further attempts.
-            this.logger.append(
+            this.log(
               'Failed to send keep-alive ping, cleaning up interval.' + e,
             );
             clearInterval(keepAlive);
           }
-        }, 60000); // Send ping every 60 seconds
+        }, 60000); // 60 sec
 
         transport.onclose = () => {
           clearInterval(keepAlive);
           if (transport.sessionId) {
-            this.logger.appendLine(`Session closed: ${transport.sessionId}`);
+            this.log(`Session closed: ${transport.sessionId}`);
             sessionsWithInitialNotification.delete(transport.sessionId);
             delete transports[transport.sessionId];
           }
         };
         mcpServer.connect(transport);
       } else {
-        this.logger.appendLine(
+        this.log(
           'Bad Request: No valid session ID provided for non-initialize request.',
         );
         res.status(400).json({
@@ -129,7 +138,7 @@ export class IDEServer {
       } catch (error) {
         const errorMessage =
           error instanceof Error ? error.message : 'Unknown error';
-        this.logger.appendLine(`Error handling MCP request: ${errorMessage}`);
+        this.log(`Error handling MCP request: ${errorMessage}`);
         if (!res.headersSent) {
           res.status(500).json({
             jsonrpc: '2.0' as const,
@@ -148,7 +157,7 @@ export class IDEServer {
         | string
         | undefined;
       if (!sessionId || !transports[sessionId]) {
-        this.logger.appendLine('Invalid or missing session ID');
+        this.log('Invalid or missing session ID');
         res.status(400).send('Invalid or missing session ID');
         return;
       }
@@ -159,9 +168,7 @@ export class IDEServer {
       } catch (error) {
         const errorMessage =
           error instanceof Error ? error.message : 'Unknown error';
-        this.logger.appendLine(
-          `Error handling session request: ${errorMessage}`,
-        );
+        this.log(`Error handling session request: ${errorMessage}`);
         if (!res.headersSent) {
           res.status(400).send('Bad Request');
         }
@@ -170,7 +177,7 @@ export class IDEServer {
       if (!sessionsWithInitialNotification.has(sessionId)) {
         sendOpenFilesChangedNotification(
           transport,
-          this.logger,
+          this.log.bind(this),
           recentFilesManager,
         );
         sessionsWithInitialNotification.add(sessionId);
@@ -187,7 +194,7 @@ export class IDEServer {
           IDE_SERVER_PORT_ENV_VAR,
           port.toString(),
         );
-        this.logger.appendLine(`IDE server listening on port ${port}`);
+        this.log(`IDE server listening on port ${port}`);
       }
     });
   }
@@ -197,12 +204,10 @@ export class IDEServer {
       await new Promise<void>((resolve, reject) => {
         this.server!.close((err?: Error) => {
           if (err) {
-            this.logger.appendLine(
-              `Error shutting down IDE server: ${err.message}`,
-            );
+            this.log(`Error shutting down IDE server: ${err.message}`);
             return reject(err);
           }
-          this.logger.appendLine(`IDE server shut down`);
+          this.log(`IDE server shut down`);
           resolve();
         });
       });
diff --git a/packages/vscode-ide-companion/src/recent-files-manager.test.ts b/packages/vscode-ide-companion/src/recent-files-manager.test.ts
index 27742ed2..97f19f30 100644
--- a/packages/vscode-ide-companion/src/recent-files-manager.test.ts
+++ b/packages/vscode-ide-companion/src/recent-files-manager.test.ts
@@ -13,11 +13,19 @@ import {
 } from './recent-files-manager.js';
 
 vi.mock('vscode', () => ({
-  EventEmitter: vi.fn(() => ({
-    event: vi.fn(),
-    fire: vi.fn(),
-    dispose: vi.fn(),
-  })),
+  EventEmitter: vi.fn(() => {
+    const listeners: Array<(e: void) => unknown> = [];
+    return {
+      event: vi.fn((listener) => {
+        listeners.push(listener);
+        return { dispose: vi.fn() };
+      }),
+      fire: vi.fn(() => {
+        listeners.forEach((listener) => listener(undefined));
+      }),
+      dispose: vi.fn(),
+    };
+  }),
   window: {
     onDidChangeActiveTextEditor: vi.fn(),
   },
@@ -29,14 +37,48 @@ vi.mock('vscode', () => ({
   Uri: {
     file: (path: string) => ({
       fsPath: path,
+      scheme: 'file',
     }),
   },
 }));
 
 describe('RecentFilesManager', () => {
   let context: vscode.ExtensionContext;
+  let onDidChangeActiveTextEditorListener: (
+    editor: vscode.TextEditor | undefined,
+  ) => void;
+  let onDidDeleteFilesListener: (e: vscode.FileDeleteEvent) => void;
+  let onDidCloseTextDocumentListener: (doc: vscode.TextDocument) => void;
+  let onDidRenameFilesListener: (e: vscode.FileRenameEvent) => void;
 
   beforeEach(() => {
+    vi.useFakeTimers();
+
+    vi.mocked(vscode.window.onDidChangeActiveTextEditor).mockImplementation(
+      (listener) => {
+        onDidChangeActiveTextEditorListener = listener;
+        return { dispose: vi.fn() };
+      },
+    );
+    vi.mocked(vscode.workspace.onDidDeleteFiles).mockImplementation(
+      (listener) => {
+        onDidDeleteFilesListener = listener;
+        return { dispose: vi.fn() };
+      },
+    );
+    vi.mocked(vscode.workspace.onDidCloseTextDocument).mockImplementation(
+      (listener) => {
+        onDidCloseTextDocumentListener = listener;
+        return { dispose: vi.fn() };
+      },
+    );
+    vi.mocked(vscode.workspace.onDidRenameFiles).mockImplementation(
+      (listener) => {
+        onDidRenameFilesListener = listener;
+        return { dispose: vi.fn() };
+      },
+    );
+
     context = {
       subscriptions: [],
     } as unknown as vscode.ExtensionContext;
@@ -44,33 +86,40 @@ describe('RecentFilesManager', () => {
 
   afterEach(() => {
     vi.restoreAllMocks();
+    vi.useRealTimers();
   });
 
-  it('adds a file to the list', () => {
+  const getUri = (path: string) =>
+    vscode.Uri.file(path) as unknown as vscode.Uri;
+
+  it('adds a file to the list', async () => {
     const manager = new RecentFilesManager(context);
-    const uri = vscode.Uri.file('/test/file1.txt');
+    const uri = getUri('/test/file1.txt');
     manager.add(uri);
+    await vi.advanceTimersByTimeAsync(100);
     expect(manager.recentFiles).toHaveLength(1);
     expect(manager.recentFiles[0].filePath).toBe('/test/file1.txt');
   });
 
-  it('moves an existing file to the top', () => {
+  it('moves an existing file to the top', async () => {
     const manager = new RecentFilesManager(context);
-    const uri1 = vscode.Uri.file('/test/file1.txt');
-    const uri2 = vscode.Uri.file('/test/file2.txt');
+    const uri1 = getUri('/test/file1.txt');
+    const uri2 = getUri('/test/file2.txt');
     manager.add(uri1);
     manager.add(uri2);
     manager.add(uri1);
+    await vi.advanceTimersByTimeAsync(100);
     expect(manager.recentFiles).toHaveLength(2);
     expect(manager.recentFiles[0].filePath).toBe('/test/file1.txt');
   });
 
-  it('does not exceed the max number of files', () => {
+  it('does not exceed the max number of files', async () => {
     const manager = new RecentFilesManager(context);
     for (let i = 0; i < MAX_FILES + 5; i++) {
-      const uri = vscode.Uri.file(`/test/file${i}.txt`);
+      const uri = getUri(`/test/file${i}.txt`);
       manager.add(uri);
     }
+    await vi.advanceTimersByTimeAsync(100);
     expect(manager.recentFiles).toHaveLength(MAX_FILES);
     expect(manager.recentFiles[0].filePath).toBe(
       `/test/file${MAX_FILES + 4}.txt`,
@@ -78,134 +127,151 @@ describe('RecentFilesManager', () => {
     expect(manager.recentFiles[MAX_FILES - 1].filePath).toBe(`/test/file5.txt`);
   });
 
-  it('fires onDidChange when a file is added', () => {
+  it('fires onDidChange when a file is added', async () => {
     const manager = new RecentFilesManager(context);
-    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
-    const uri = vscode.Uri.file('/test/file1.txt');
+    const onDidChangeSpy = vi.fn();
+    manager.onDidChange(onDidChangeSpy);
+
+    const uri = getUri('/test/file1.txt');
     manager.add(uri);
-    expect(spy).toHaveBeenCalled();
+
+    await vi.advanceTimersByTimeAsync(100);
+    expect(onDidChangeSpy).toHaveBeenCalled();
   });
 
-  it('removes a file when it is closed', () => {
+  it('removes a file when it is closed', async () => {
     const manager = new RecentFilesManager(context);
-    const uri = vscode.Uri.file('/test/file1.txt');
+    const uri = getUri('/test/file1.txt');
     manager.add(uri);
+    await vi.advanceTimersByTimeAsync(100);
     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);
+    onDidCloseTextDocumentListener({ uri } as vscode.TextDocument);
+    await vi.advanceTimersByTimeAsync(100);
 
     expect(manager.recentFiles).toHaveLength(0);
   });
 
-  it('fires onDidChange when a file is removed', () => {
+  it('fires onDidChange when a file is removed', async () => {
     const manager = new RecentFilesManager(context);
-    const uri = vscode.Uri.file('/test/file1.txt');
+    const uri = getUri('/test/file1.txt');
     manager.add(uri);
+    await vi.advanceTimersByTimeAsync(100);
+
+    const onDidChangeSpy = vi.fn();
+    manager.onDidChange(onDidChangeSpy);
 
-    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
-    const closeHandler = vi.mocked(vscode.workspace.onDidCloseTextDocument).mock
-      .calls[0][0];
-    closeHandler({ uri } as vscode.TextDocument);
+    onDidCloseTextDocumentListener({ uri } as vscode.TextDocument);
+    await vi.advanceTimersByTimeAsync(100);
 
-    expect(spy).toHaveBeenCalled();
+    expect(onDidChangeSpy).toHaveBeenCalled();
   });
 
-  it('removes a file when it is deleted', () => {
+  it('removes a file when it is deleted', async () => {
     const manager = new RecentFilesManager(context);
-    const uri1 = vscode.Uri.file('/test/file1.txt');
-    const uri2 = vscode.Uri.file('/test/file2.txt');
+    const uri1 = getUri('/test/file1.txt');
+    const uri2 = getUri('/test/file2.txt');
     manager.add(uri1);
     manager.add(uri2);
+    await vi.advanceTimersByTimeAsync(100);
     expect(manager.recentFiles).toHaveLength(2);
 
-    // Simulate deleting a file
-    const deleteHandler = vi.mocked(vscode.workspace.onDidDeleteFiles).mock
-      .calls[0][0];
-    deleteHandler({ files: [uri1] });
+    onDidDeleteFilesListener({ files: [uri1] });
+    await vi.advanceTimersByTimeAsync(100);
 
     expect(manager.recentFiles).toHaveLength(1);
     expect(manager.recentFiles[0].filePath).toBe('/test/file2.txt');
   });
 
-  it('fires onDidChange when a file is deleted', () => {
+  it('fires onDidChange when a file is deleted', async () => {
     const manager = new RecentFilesManager(context);
-    const uri = vscode.Uri.file('/test/file1.txt');
+    const uri = getUri('/test/file1.txt');
     manager.add(uri);
+    await vi.advanceTimersByTimeAsync(100);
+
+    const onDidChangeSpy = vi.fn();
+    manager.onDidChange(onDidChangeSpy);
 
-    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
-    const deleteHandler = vi.mocked(vscode.workspace.onDidDeleteFiles).mock
-      .calls[0][0];
-    deleteHandler({ files: [uri] });
+    onDidDeleteFilesListener({ files: [uri] });
+    await vi.advanceTimersByTimeAsync(100);
 
-    expect(spy).toHaveBeenCalled();
+    expect(onDidChangeSpy).toHaveBeenCalled();
   });
 
-  it('removes multiple files when they are deleted', () => {
+  it('removes multiple files when they are deleted', async () => {
     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');
+    const uri1 = getUri('/test/file1.txt');
+    const uri2 = getUri('/test/file2.txt');
+    const uri3 = getUri('/test/file3.txt');
     manager.add(uri1);
     manager.add(uri2);
     manager.add(uri3);
+    await vi.advanceTimersByTimeAsync(100);
     expect(manager.recentFiles).toHaveLength(3);
 
-    // Simulate deleting multiple files
-    const deleteHandler = vi.mocked(vscode.workspace.onDidDeleteFiles).mock
-      .calls[0][0];
-    deleteHandler({ files: [uri1, uri3] });
+    onDidDeleteFilesListener({ files: [uri1, uri3] });
+    await vi.advanceTimersByTimeAsync(100);
 
     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');
+    const uri1 = getUri('/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');
+    const uri2 = getUri('/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', () => {
+  it('fires onDidChange only once when adding an existing file', async () => {
     const manager = new RecentFilesManager(context);
-    const uri = vscode.Uri.file('/test/file1.txt');
+    const uri = getUri('/test/file1.txt');
     manager.add(uri);
+    await vi.advanceTimersByTimeAsync(100);
+
+    const onDidChangeSpy = vi.fn();
+    manager.onDidChange(onDidChangeSpy);
 
-    const spy = vi.spyOn(manager['onDidChangeEmitter'], 'fire');
     manager.add(uri);
-    expect(spy).toHaveBeenCalledTimes(1);
+    await vi.advanceTimersByTimeAsync(100);
+    expect(onDidChangeSpy).toHaveBeenCalledTimes(1);
   });
 
-  it('updates the file when it is renamed', () => {
+  it('updates the file when it is renamed', async () => {
     const manager = new RecentFilesManager(context);
-    const oldUri = vscode.Uri.file('/test/file1.txt');
-    const newUri = vscode.Uri.file('/test/file2.txt');
+    const oldUri = getUri('/test/file1.txt');
+    const newUri = getUri('/test/file2.txt');
     manager.add(oldUri);
+    await vi.advanceTimersByTimeAsync(100);
     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 }] });
+    onDidRenameFilesListener({ files: [{ oldUri, newUri }] });
+    await vi.advanceTimersByTimeAsync(100);
 
     expect(manager.recentFiles).toHaveLength(1);
     expect(manager.recentFiles[0].filePath).toBe('/test/file2.txt');
   });
+
+  it('adds a file when the active editor changes', async () => {
+    const manager = new RecentFilesManager(context);
+    const uri = getUri('/test/file1.txt');
+
+    onDidChangeActiveTextEditorListener({
+      document: { uri },
+    } as vscode.TextEditor);
+    await vi.advanceTimersByTimeAsync(100);
+
+    expect(manager.recentFiles).toHaveLength(1);
+    expect(manager.recentFiles[0].filePath).toBe('/test/file1.txt');
+  });
 });
diff --git a/packages/vscode-ide-companion/src/recent-files-manager.ts b/packages/vscode-ide-companion/src/recent-files-manager.ts
index 84316363..cbe7e9a9 100644
--- a/packages/vscode-ide-companion/src/recent-files-manager.ts
+++ b/packages/vscode-ide-companion/src/recent-files-manager.ts
@@ -16,14 +16,14 @@ interface RecentFile {
 
 /**
  * Keeps track of the 10 most recently-opened files
- * opened less than 5 ago. If a file is closed or deleted,
- * it will be removed. If the length is maxxed out,
- * the now-removed file will not be replaced by an older file.
+ * opened less than 5 min ago. If a file is closed or deleted,
+ * it will be removed. If the max length is reached, older files will get removed first.
  */
 export class RecentFilesManager {
   private readonly files: RecentFile[] = [];
   private readonly onDidChangeEmitter = new vscode.EventEmitter<void>();
   readonly onDidChange = this.onDidChangeEmitter.event;
+  private debounceTimer: NodeJS.Timeout | undefined;
 
   constructor(private readonly context: vscode.ExtensionContext) {
     const editorWatcher = vscode.window.onDidChangeActiveTextEditor(
@@ -33,7 +33,7 @@ export class RecentFilesManager {
         }
       },
     );
-    const fileWatcher = vscode.workspace.onDidDeleteFiles((event) => {
+    const deleteWatcher = vscode.workspace.onDidDeleteFiles((event) => {
       for (const uri of event.files) {
         this.remove(uri);
       }
@@ -49,12 +49,21 @@ export class RecentFilesManager {
     });
     context.subscriptions.push(
       editorWatcher,
-      fileWatcher,
+      deleteWatcher,
       closeWatcher,
       renameWatcher,
     );
   }
 
+  private fireWithDebounce() {
+    if (this.debounceTimer) {
+      clearTimeout(this.debounceTimer);
+    }
+    this.debounceTimer = setTimeout(() => {
+      this.onDidChangeEmitter.fire();
+    }, 50); // 50ms
+  }
+
   private remove(uri: vscode.Uri, fireEvent = true) {
     const index = this.files.findIndex(
       (file) => file.uri.fsPath === uri.fsPath,
@@ -62,21 +71,23 @@ export class RecentFilesManager {
     if (index !== -1) {
       this.files.splice(index, 1);
       if (fireEvent) {
-        this.onDidChangeEmitter.fire();
+        this.fireWithDebounce();
       }
     }
   }
 
   add(uri: vscode.Uri) {
-    // Remove if it already exists to avoid duplicates and move it to the top.
-    this.remove(uri, false);
+    if (uri.scheme !== 'file') {
+      return;
+    }
 
+    this.remove(uri, false);
     this.files.unshift({ uri, timestamp: Date.now() });
 
     if (this.files.length > MAX_FILES) {
       this.files.pop();
     }
-    this.onDidChangeEmitter.fire();
+    this.fireWithDebounce();
   }
 
   get recentFiles(): Array<{ filePath: string; timestamp: number }> {
diff --git a/packages/vscode-ide-companion/src/utils/logger.ts b/packages/vscode-ide-companion/src/utils/logger.ts
new file mode 100644
index 00000000..b3f8ad1e
--- /dev/null
+++ b/packages/vscode-ide-companion/src/utils/logger.ts
@@ -0,0 +1,18 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import * as vscode from 'vscode';
+
+export function createLogger(
+  context: vscode.ExtensionContext,
+  logger: vscode.OutputChannel,
+) {
+  return (message: string) => {
+    if (context.extensionMode === vscode.ExtensionMode.Development) {
+      logger.appendLine(message);
+    }
+  };
+}