Support logging in with Application Default Credentials (#1157)

Co-authored-by: N. Taylor Mullen <[email protected]>

1 files changed, 14 insertions, 6 deletions

diff --git a/packages/core/src/code_assist/codeAssist.ts b/packages/core/src/code_assist/codeAssist.ts
index 5df1502b..92b53104 100644
--- a/packages/core/src/code_assist/codeAssist.ts
+++ b/packages/core/src/code_assist/codeAssist.ts
@@ -4,6 +4,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
+import { GoogleAuth, AuthClient } from 'google-auth-library';
 import { ContentGenerator } from '../core/contentGenerator.js';
 import { getOauthClient } from './oauth2.js';
 import { setupUser } from './setup.js';
@@ -12,10 +13,17 @@ import { CodeAssistServer, HttpOptions } from './server.js';
 export async function createCodeAssistContentGenerator(
   httpOptions: HttpOptions,
 ): Promise<ContentGenerator> {
-  const oauth2Client = await getOauthClient();
-  const projectId = await setupUser(
-    oauth2Client,
-    process.env.GOOGLE_CLOUD_PROJECT,
-  );
-  return new CodeAssistServer(oauth2Client, projectId, httpOptions);
+  const authClient = await getAuthClient();
+  const projectId = await setupUser(authClient);
+  return new CodeAssistServer(authClient, projectId, httpOptions);
+}
+
+async function getAuthClient(): Promise<AuthClient> {
+  try {
+    // Try for Application Default Credentials.
+    return await new GoogleAuth().getClient();
+  } catch (_) {
+    // No Application Default Credentials so try Oauth.
+    return await getOauthClient();
+  }
 }