feat(core): require user consent before MCP server OAuth (#18132)

packages/core/src/code_assist/oauth2.test.ts

@@ -9,7 +9,6 @@ import type { Mock } from 'vitest';
 import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
 import {
   getOauthClient,
-  getConsentForOauth,
   resetOauthClientForTesting,
   clearCachedCredentialFile,
   clearOauthClientCache,
@@ -30,10 +29,7 @@ import { FORCE_ENCRYPTED_FILE_ENV_VAR } from '../mcp/token-storage/index.js';
 import { GEMINI_DIR, homedir as pathsHomedir } from '../utils/paths.js';
 import { debugLogger } from '../utils/debugLogger.js';
 import { writeToStdout } from '../utils/stdio.js';
-import {
-  FatalAuthenticationError,
-  FatalCancellationError,
-} from '../utils/errors.js';
+import { FatalCancellationError } from '../utils/errors.js';
 import process from 'node:process';
 import { coreEvents } from '../utils/events.js';
 
@@ -1255,6 +1251,18 @@ describe('oauth2', () => {
         stdinOnSpy.mockRestore();
         stdinRemoveListenerSpy.mockRestore();
       });
+
+      it('should throw FatalCancellationError when consent is denied', async () => {
+        vi.spyOn(coreEvents, 'emitConsentRequest').mockImplementation(
+          (payload) => {
+            payload.onConfirm(false);
+          },
+        );
+
+        await expect(
+          getOauthClient(AuthType.LOGIN_WITH_GOOGLE, mockConfig),
+        ).rejects.toThrow(FatalCancellationError);
+      });
     });
 
     describe('clearCachedCredentialFile', () => {
@@ -1515,84 +1523,4 @@ describe('oauth2', () => {
       expect(fs.existsSync(credsPath)).toBe(true); // The unencrypted file should remain
     });
   });
-
-  describe('getConsentForOauth', () => {
-    it('should use coreEvents when listeners are present', async () => {
-      vi.restoreAllMocks();
-      const mockEmitConsentRequest = vi.spyOn(coreEvents, 'emitConsentRequest');
-      const mockListenerCount = vi
-        .spyOn(coreEvents, 'listenerCount')
-        .mockReturnValue(1);
-
-      mockEmitConsentRequest.mockImplementation((payload) => {
-        payload.onConfirm(true);
-      });
-
-      const result = await getConsentForOauth();
-
-      expect(result).toBe(true);
-      expect(mockEmitConsentRequest).toHaveBeenCalled();
-
-      mockListenerCount.mockRestore();
-      mockEmitConsentRequest.mockRestore();
-    });
-
-    it('should use readline when no listeners are present and stdin is a TTY', async () => {
-      vi.restoreAllMocks();
-      const mockListenerCount = vi
-        .spyOn(coreEvents, 'listenerCount')
-        .mockReturnValue(0);
-      const originalIsTTY = process.stdin.isTTY;
-      Object.defineProperty(process.stdin, 'isTTY', {
-        value: true,
-        configurable: true,
-      });
-
-      const mockReadline = {
-        on: vi.fn((event, callback) => {
-          if (event === 'line') {
-            callback('y');
-          }
-        }),
-        close: vi.fn(),
-      };
-      (readline.createInterface as Mock).mockReturnValue(mockReadline);
-
-      const result = await getConsentForOauth();
-
-      expect(result).toBe(true);
-      expect(readline.createInterface).toHaveBeenCalled();
-      expect(writeToStdout).toHaveBeenCalledWith(
-        expect.stringContaining('Do you want to continue? [Y/n]: '),
-      );
-
-      mockListenerCount.mockRestore();
-      Object.defineProperty(process.stdin, 'isTTY', {
-        value: originalIsTTY,
-        configurable: true,
-      });
-    });
-
-    it('should throw FatalAuthenticationError when no listeners and not a TTY', async () => {
-      vi.restoreAllMocks();
-      const mockListenerCount = vi
-        .spyOn(coreEvents, 'listenerCount')
-        .mockReturnValue(0);
-      const originalIsTTY = process.stdin.isTTY;
-      Object.defineProperty(process.stdin, 'isTTY', {
-        value: false,
-        configurable: true,
-      });
-
-      await expect(getConsentForOauth()).rejects.toThrow(
-        FatalAuthenticationError,
-      );
-
-      mockListenerCount.mockRestore();
-      Object.defineProperty(process.stdin, 'isTTY', {
-        value: originalIsTTY,
-        configurable: true,
-      });
-    });
-  });
 });

packages/core/src/code_assist/oauth2.ts

@@ -45,6 +45,7 @@ import {
   exitAlternateScreen,
 } from '../utils/terminal.js';
 import { coreEvents, CoreEvent } from '../utils/events.js';
+import { getConsentForOauth } from '../utils/authConsent.js';
 
 export const authEvents = new EventEmitter();
 
@@ -269,7 +270,7 @@ async function initOauthClient(
 
     await triggerPostAuthCallbacks(client.credentials);
   } else {
-    const userConsent = await getConsentForOauth();
+    const userConsent = await getConsentForOauth('Code Assist login required.');
     if (!userConsent) {
       throw new FatalCancellationError('Authentication cancelled by user.');
     }
@@ -377,53 +378,6 @@ async function initOauthClient(
   return client;
 }
 
-export async function getConsentForOauth(): Promise<boolean> {
-  const prompt =
-    'Code Assist login required. Opening authentication page in your browser. ';
-
-  if (coreEvents.listenerCount(CoreEvent.ConsentRequest) === 0) {
-    if (!process.stdin.isTTY) {
-      throw new FatalAuthenticationError(
-        'Code Assist login required, but interactive consent could not be obtained.\n' +
-          'Please run Gemini CLI in an interactive terminal to authenticate, or use NO_BROWSER=true for manual authentication.',
-      );
-    }
-    return getOauthConsentNonInteractive(prompt);
-  }
-
-  return getOauthConsentInteractive(prompt);
-}
-
-async function getOauthConsentNonInteractive(prompt: string) {
-  const rl = readline.createInterface({
-    input: process.stdin,
-    output: createWorkingStdio().stdout,
-    terminal: true,
-  });
-
-  const fullPrompt = prompt + 'Do you want to continue? [Y/n]: ';
-  writeToStdout(`\n${fullPrompt}`);
-
-  return new Promise<boolean>((resolve) => {
-    rl.on('line', (answer) => {
-      rl.close();
-      resolve(['y', ''].includes(answer.trim().toLowerCase()));
-    });
-  });
-}
-
-async function getOauthConsentInteractive(prompt: string) {
-  const fullPrompt = prompt + '\n\nDo you want to continue?';
-  return new Promise<boolean>((resolve) => {
-    coreEvents.emitConsentRequest({
-      prompt: fullPrompt,
-      onConfirm: (confirmed: boolean) => {
-        resolve(confirmed);
-      },
-    });
-  });
-}
-
 export async function getOauthClient(
   authType: AuthType,
   config: Config,