[ide-mode] Support multi-folder workspaces (#6177)

packages/vscode-ide-companion/src/extension-multi-folder.test.ts

@@ -0,0 +1,186 @@
+/**
+ * @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 { activate } from './extension.js';
+
+vi.mock('vscode', () => ({
+  window: {
+    createOutputChannel: vi.fn(() => ({
+      appendLine: vi.fn(),
+    })),
+    showInformationMessage: vi.fn(),
+    createTerminal: vi.fn(() => ({
+      show: vi.fn(),
+      sendText: vi.fn(),
+    })),
+    onDidChangeActiveTextEditor: vi.fn(),
+    activeTextEditor: undefined,
+    tabGroups: {
+      all: [],
+      close: vi.fn(),
+    },
+    showTextDocument: vi.fn(),
+  },
+  workspace: {
+    workspaceFolders: [],
+    onDidCloseTextDocument: vi.fn(),
+    registerTextDocumentContentProvider: vi.fn(),
+    onDidChangeWorkspaceFolders: vi.fn(),
+  },
+  commands: {
+    registerCommand: vi.fn(),
+    executeCommand: vi.fn(),
+  },
+  Uri: {
+    joinPath: vi.fn(),
+    file: (path: string) => ({ fsPath: path }),
+  },
+  ExtensionMode: {
+    Development: 1,
+    Production: 2,
+  },
+  EventEmitter: vi.fn(() => ({
+    event: vi.fn(),
+    fire: vi.fn(),
+    dispose: vi.fn(),
+  })),
+}));
+
+describe('activate with multiple folders', () => {
+  let context: vscode.ExtensionContext;
+  let onDidChangeWorkspaceFoldersCallback: (
+    e: vscode.WorkspaceFoldersChangeEvent,
+  ) => void;
+
+  beforeEach(() => {
+    context = {
+      subscriptions: [],
+      environmentVariableCollection: {
+        replace: vi.fn(),
+      },
+      globalState: {
+        get: vi.fn().mockReturnValue(true),
+        update: vi.fn(),
+      },
+      extensionUri: {
+        fsPath: '/path/to/extension',
+      },
+    } as unknown as vscode.ExtensionContext;
+
+    vi.mocked(vscode.workspace.onDidChangeWorkspaceFolders).mockImplementation(
+      (callback) => {
+        onDidChangeWorkspaceFoldersCallback = callback;
+        return { dispose: vi.fn() };
+      },
+    );
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('should set a single folder path', async () => {
+    const workspaceFoldersSpy = vi.spyOn(
+      vscode.workspace,
+      'workspaceFolders',
+      'get',
+    );
+    workspaceFoldersSpy.mockReturnValue([
+      { uri: { fsPath: '/foo/bar' } },
+    ] as vscode.WorkspaceFolder[]);
+
+    await activate(context);
+
+    expect(context.environmentVariableCollection.replace).toHaveBeenCalledWith(
+      'GEMINI_CLI_IDE_WORKSPACE_PATH',
+      '/foo/bar',
+    );
+  });
+
+  it('should set multiple folder paths, separated by a colon', async () => {
+    const workspaceFoldersSpy = vi.spyOn(
+      vscode.workspace,
+      'workspaceFolders',
+      'get',
+    );
+    workspaceFoldersSpy.mockReturnValue([
+      { uri: { fsPath: '/foo/bar' } },
+      { uri: { fsPath: '/baz/qux' } },
+    ] as vscode.WorkspaceFolder[]);
+
+    await activate(context);
+
+    expect(context.environmentVariableCollection.replace).toHaveBeenCalledWith(
+      'GEMINI_CLI_IDE_WORKSPACE_PATH',
+      '/foo/bar:/baz/qux',
+    );
+  });
+
+  it('should set an empty string if no folders are open', async () => {
+    const workspaceFoldersSpy = vi.spyOn(
+      vscode.workspace,
+      'workspaceFolders',
+      'get',
+    );
+    workspaceFoldersSpy.mockReturnValue([]);
+
+    await activate(context);
+
+    expect(context.environmentVariableCollection.replace).toHaveBeenCalledWith(
+      'GEMINI_CLI_IDE_WORKSPACE_PATH',
+      '',
+    );
+  });
+
+  it('should update the path when workspace folders change', async () => {
+    const workspaceFoldersSpy = vi.spyOn(
+      vscode.workspace,
+      'workspaceFolders',
+      'get',
+    );
+    workspaceFoldersSpy.mockReturnValue([
+      { uri: { fsPath: '/foo/bar' } },
+    ] as vscode.WorkspaceFolder[]);
+
+    await activate(context);
+
+    expect(context.environmentVariableCollection.replace).toHaveBeenCalledWith(
+      'GEMINI_CLI_IDE_WORKSPACE_PATH',
+      '/foo/bar',
+    );
+
+    // Simulate adding a folder
+    workspaceFoldersSpy.mockReturnValue([
+      { uri: { fsPath: '/foo/bar' } },
+      { uri: { fsPath: '/baz/qux' } },
+    ] as vscode.WorkspaceFolder[]);
+    onDidChangeWorkspaceFoldersCallback({
+      added: [{ uri: { fsPath: '/baz/qux' } } as vscode.WorkspaceFolder],
+      removed: [],
+    });
+
+    expect(context.environmentVariableCollection.replace).toHaveBeenCalledWith(
+      'GEMINI_CLI_IDE_WORKSPACE_PATH',
+      '/foo/bar:/baz/qux',
+    );
+
+    // Simulate removing a folder
+    workspaceFoldersSpy.mockReturnValue([
+      { uri: { fsPath: '/baz/qux' } },
+    ] as vscode.WorkspaceFolder[]);
+    onDidChangeWorkspaceFoldersCallback({
+      added: [],
+      removed: [{ uri: { fsPath: '/foo/bar' } } as vscode.WorkspaceFolder],
+    });
+
+    expect(context.environmentVariableCollection.replace).toHaveBeenCalledWith(
+      'GEMINI_CLI_IDE_WORKSPACE_PATH',
+      '/baz/qux',
+    );
+  });
+});

packages/vscode-ide-companion/src/extension.ts

@@ -20,11 +20,13 @@ let log: (message: string) => void = () => {};
 
 function updateWorkspacePath(context: vscode.ExtensionContext) {
   const workspaceFolders = vscode.workspace.workspaceFolders;
-  if (workspaceFolders && workspaceFolders.length === 1) {
-    const workspaceFolder = workspaceFolders[0];
+  if (workspaceFolders && workspaceFolders.length > 0) {
+    const workspacePaths = workspaceFolders
+      .map((folder) => folder.uri.fsPath)
+      .join(':');
     context.environmentVariableCollection.replace(
       IDE_WORKSPACE_PATH_ENV_VAR,
-      workspaceFolder.uri.fsPath,
+      workspacePaths,
     );
   } else {
     context.environmentVariableCollection.replace(