feat(extensions): add support for plan directory in extension manifest (#20354)

Co-authored-by: Mahima Shanware <mshanware@google.com>
Co-authored-by: Jerop Kipruto <jerop@google.com>

packages/core/src/config/config.test.ts

@@ -2950,9 +2950,11 @@ describe('Plans Directory Initialization', () => {
 
   afterEach(() => {
     vi.mocked(fs.promises.mkdir).mockRestore();
+    vi.mocked(fs.promises.access).mockRestore?.();
   });
 
-  it('should create plans directory and add it to workspace context when plan is enabled', async () => {
+  it('should add plans directory to workspace context if it exists', async () => {
+    vi.spyOn(fs.promises, 'access').mockResolvedValue(undefined);
     const config = new Config({
       ...baseParams,
       plan: true,
@@ -2961,14 +2963,32 @@ describe('Plans Directory Initialization', () => {
     await config.initialize();
 
     const plansDir = config.storage.getPlansDir();
-    expect(fs.promises.mkdir).toHaveBeenCalledWith(plansDir, {
-      recursive: true,
-    });
+    // Should NOT create the directory eagerly
+    expect(fs.promises.mkdir).not.toHaveBeenCalled();
+    // Should check if it exists
+    expect(fs.promises.access).toHaveBeenCalledWith(plansDir);
 
     const context = config.getWorkspaceContext();
     expect(context.getDirectories()).toContain(plansDir);
   });
 
+  it('should NOT add plans directory to workspace context if it does not exist', async () => {
+    vi.spyOn(fs.promises, 'access').mockRejectedValue({ code: 'ENOENT' });
+    const config = new Config({
+      ...baseParams,
+      plan: true,
+    });
+
+    await config.initialize();
+
+    const plansDir = config.storage.getPlansDir();
+    expect(fs.promises.mkdir).not.toHaveBeenCalled();
+    expect(fs.promises.access).toHaveBeenCalledWith(plansDir);
+
+    const context = config.getWorkspaceContext();
+    expect(context.getDirectories()).not.toContain(plansDir);
+  });
+
   it('should NOT create plans directory or add it to workspace context when plan is disabled', async () => {
     const config = new Config({
       ...baseParams,

packages/core/src/config/config.ts

@@ -339,6 +339,15 @@ export interface GeminiCLIExtension {
    * Safety checkers contributed by this extension.
    */
   checkers?: SafetyCheckerRule[];
+  /**
+   * Planning features configuration contributed by this extension.
+   */
+  plan?: {
+    /**
+     * The directory where planning artifacts are stored.
+     */
+    directory?: string;
+  };
 }
 
 export interface ExtensionInstallMetadata {
@@ -1093,8 +1102,15 @@ export class Config implements McpContext {
     // Add plans directory to workspace context for plan file storage
     if (this.planEnabled) {
       const plansDir = this.storage.getPlansDir();
-      await fs.promises.mkdir(plansDir, { recursive: true });
-      this.workspaceContext.addDirectory(plansDir);
+      try {
+        await fs.promises.access(plansDir);
+        this.workspaceContext.addDirectory(plansDir);
+      } catch {
+        // Directory does not exist yet, so we don't add it to the workspace context.
+        // It will be created when the first plan is written. Since custom plan
+        // directories must be within the project root, they are automatically
+        // covered by the project-wide file discovery once created.
+      }
     }
 
     // Initialize centralized FileDiscoveryService