fix: enable browser_agent in integration tests and add localhost fixture tests (#24523)

integration-tests/browser-agent-localhost.test.ts

@@ -0,0 +1,161 @@
+/**
+ * @license
+ * Copyright 2026 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { TestRig, assertModelHasOutput } from './test-helper.js';
+import { dirname, join } from 'node:path';
+import { fileURLToPath } from 'node:url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = dirname(__filename);
+
+describe('browser-agent-localhost', () => {
+  let rig: TestRig;
+
+  const browserSettings = {
+    agents: {
+      overrides: {
+        browser_agent: {
+          enabled: true,
+        },
+      },
+      browser: {
+        headless: true,
+        sessionMode: 'isolated' as const,
+      },
+    },
+  };
+
+  beforeEach(() => {
+    rig = new TestRig();
+  });
+
+  afterEach(async () => {
+    await rig.cleanup();
+  });
+
+  it('should navigate to localhost fixture and read page content', async () => {
+    rig.setup('localhost-navigate', {
+      fakeResponsesPath: join(
+        __dirname,
+        'browser-agent-localhost.navigate.responses',
+      ),
+      settings: browserSettings,
+    });
+
+    const result = await rig.run({
+      args: 'Navigate to http://127.0.0.1:18923/index.html and tell me the page title and list all links.',
+    });
+
+    assertModelHasOutput(result);
+
+    const toolLogs = rig.readToolLogs();
+    const browserAgentCall = toolLogs.find(
+      (t) => t.toolRequest.name === 'browser_agent',
+    );
+    expect(
+      browserAgentCall,
+      'Expected browser_agent to be called',
+    ).toBeDefined();
+  });
+
+  it('should fill out and submit a form on localhost', async () => {
+    rig.setup('localhost-form', {
+      fakeResponsesPath: join(
+        __dirname,
+        'browser-agent-localhost.form.responses',
+      ),
+      settings: browserSettings,
+    });
+
+    const result = await rig.run({
+      args: "Navigate to http://127.0.0.1:18923/form.html, fill in name='Test User', email='test@example.com', message='Hello World', and submit the form.",
+    });
+
+    assertModelHasOutput(result);
+
+    const toolLogs = rig.readToolLogs();
+    const browserAgentCall = toolLogs.find(
+      (t) => t.toolRequest.name === 'browser_agent',
+    );
+    expect(
+      browserAgentCall,
+      'Expected browser_agent to be called',
+    ).toBeDefined();
+  });
+
+  it('should navigate through a multi-step flow', async () => {
+    rig.setup('localhost-multistep', {
+      fakeResponsesPath: join(
+        __dirname,
+        'browser-agent-localhost.multistep.responses',
+      ),
+      settings: browserSettings,
+    });
+
+    const result = await rig.run({
+      args: "Go to http://127.0.0.1:18923/multi-step/step1.html, fill in 'testuser' as username, click Next, then click Finish on step 2. Report the result.",
+    });
+
+    assertModelHasOutput(result);
+
+    const toolLogs = rig.readToolLogs();
+    const browserAgentCall = toolLogs.find(
+      (t) => t.toolRequest.name === 'browser_agent',
+    );
+    expect(
+      browserAgentCall,
+      'Expected browser_agent to be called',
+    ).toBeDefined();
+  });
+
+  it('should handle dynamically loaded content', async () => {
+    rig.setup('localhost-dynamic', {
+      fakeResponsesPath: join(
+        __dirname,
+        'browser-agent-localhost.dynamic.responses',
+      ),
+      settings: browserSettings,
+    });
+
+    const result = await rig.run({
+      args: 'Navigate to http://127.0.0.1:18923/dynamic.html, wait for content to load, and tell me what items appear.',
+    });
+
+    assertModelHasOutput(result);
+
+    const toolLogs = rig.readToolLogs();
+    const browserAgentCall = toolLogs.find(
+      (t) => t.toolRequest.name === 'browser_agent',
+    );
+    expect(
+      browserAgentCall,
+      'Expected browser_agent to be called',
+    ).toBeDefined();
+  });
+
+  it('should take a screenshot of localhost page', async () => {
+    rig.setup('localhost-screenshot', {
+      fakeResponsesPath: join(
+        __dirname,
+        'browser-agent-localhost.screenshot.responses',
+      ),
+      settings: browserSettings,
+    });
+
+    const result = await rig.run({
+      args: 'Navigate to http://127.0.0.1:18923/index.html and take a screenshot.',
+    });
+
+    assertModelHasOutput(result);
+
+    const toolLogs = rig.readToolLogs();
+    const browserCalls = toolLogs.filter(
+      (t) => t.toolRequest.name === 'browser_agent',
+    );
+    expect(browserCalls.length).toBeGreaterThan(0);
+  });
+});