Declare module for types, to fix build error

Author: erikeldridge

packages/ai/src/api.ts

@@ -14,10 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-// Imports navigator.userAgentData types.
-// The user-agent-data-types package isn't intended for modular imports.
-// eslint-disable-next-line @typescript-eslint/triple-slash-reference
-/// <reference types="user-agent-data-types" />
+
 import { FirebaseApp, getApp, _getProvider } from '@firebase/app';
 import { Provider } from '@firebase/component';
 import { getModularInstance } from '@firebase/util';
@@ -37,6 +34,7 @@ import { encodeInstanceIdentifier } from './helpers';
 import { GoogleAIBackend, VertexAIBackend } from './backend';
 import { ChromeAdapter } from './methods/chrome-adapter';
 import { LanguageModel } from './types/language-model';
+import { NavigatorUA } from './types/user-agent-data';
 
 export { ChatSession } from './methods/chat-session';
 export * from './requests/schema-builder';
@@ -178,7 +176,7 @@ export function getGenerativeModel(
     inCloudParams,
     new ChromeAdapter(
       window.LanguageModel as LanguageModel,
-      window.navigator.userAgentData as UADataValues,
+      (window.navigator as NavigatorUA).userAgentData,
       hybridParams.mode,
       hybridParams.onDeviceParams
     ),

packages/ai/src/methods/chrome-adapter.test.ts

@@ -14,10 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-// Imports navigator.userAgentData types.
-// The user-agent-data-types package isn't intended for modular imports.
-// eslint-disable-next-line @typescript-eslint/triple-slash-reference
-/// <reference types="user-agent-data-types" />
+
 import { AIError } from '../errors';
 import { expect, use } from 'chai';
 import sinonChai from 'sinon-chai';
@@ -29,6 +26,7 @@ import {
   LanguageModelCreateOptions,
   LanguageModelMessage
 } from '../types/language-model';
+import { UADataValues } from '../types/user-agent-data';
 import { match, stub } from 'sinon';
 import { GenerateContentRequest, AIErrorCode } from '../types';
 import { Schema } from '../api';
@@ -137,7 +135,9 @@ describe('ChromeAdapter', () => {
           availability: async () => Availability.available
         } as LanguageModel,
         // Defines user agent, but no supported browser.
-        { brands: [] } as UADataValues,
+        {
+          brands: []
+        } as UADataValues,
         'prefer_on_device'
       );
       expect(
@@ -152,29 +152,25 @@ describe('ChromeAdapter', () => {
           availability: async () => Availability.available
         } as LanguageModel,
         {
+          // Defines supported browser.
           brands: [{ brand: 'Google Chrome', version: '138' }]
         } as UADataValues,
         'prefer_on_device'
       );
-      for (const mimeType of ChromeAdapter.SUPPORTED_MIME_TYPES) {
-        expect(
-          await adapter.isAvailable({
-            contents: [
-              {
-                role: 'user',
-                parts: [
-                  {
-                    inlineData: {
-                      mimeType,
-                      data: ''
-                    }
-                  }
-                ]
-              }
-            ]
-          })
-        ).to.be.true;
-      }
+      expect(
+        await adapter.isAvailable({
+          contents: [
+            {
+              role: 'user',
+              parts: [
+                {
+                  text: 'hi'
+                }
+              ]
+            }
+          ]
+        })
+      ).to.be.true;
     });
     it('returns false if request content has "function" role', async () => {
       const adapter = new ChromeAdapter(

packages/ai/src/methods/chrome-adapter.ts

@@ -14,10 +14,7 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-// Imports navigator.userAgentData types.
-// The user-agent-data-types package isn't intended for modular imports.
-// eslint-disable-next-line @typescript-eslint/triple-slash-reference
-/// <reference types="user-agent-data-types" />
+
 import { AIError } from '../errors';
 import { logger } from '../logger';
 import {
@@ -40,6 +37,7 @@ import {
   LanguageModelMessageRole,
   LanguageModelMessageType
 } from '../types/language-model';
+import { UADataValues } from '../types/user-agent-data';
 import deepMerge from 'deepmerge';
 
 /**

packages/ai/src/types/user-agent-data.ts

@@ -0,0 +1,43 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Exports the minimal subset of
+ * https://github.com/lukewarlow/user-agent-data-types
+ * required by this SDK. That package is designed to be
+ * imported using triple slash references, which are
+ * prohibited in this SDK by TSLint.
+ */
+
+export interface NavigatorUA {
+  readonly userAgentData?: NavigatorUAData;
+}
+
+interface NavigatorUABrandVersion {
+  readonly brand: string;
+  readonly version: string;
+}
+
+export interface UADataValues {
+  readonly brands?: NavigatorUABrandVersion[];
+}
+
+interface UALowEntropyJSON {
+  readonly brands: NavigatorUABrandVersion[];
+}
+
+interface NavigatorUAData extends UALowEntropyJSON {}