Chrome DevTools Testing

A Playwright-based browser testing skill for Claude Code that connects directly to Chrome via CDP. Supports batch scripting (multiple actions per turn), auto-wait, ARIA snapshots, and full DevTools debugging.

Inspired by SawyerHood/dev-browser.

Features

Batch Scripting: Execute multiple browser actions in a single heredoc script
Persistent Pages: Browser pages survive client disconnections
Smart Page Load Detection: Filters ads/tracking, handles stuck requests gracefully
ARIA Snapshots: Accessibility tree with refs for element targeting
Playwright Locators: Robust element selection with auto-wait
DevTools Debugging: Console capture, network monitoring, performance tracing

Installation

cd ~/.claude/skills/chrome-devtools-testing
bun install

Usage

1. Start the Server

bun run start-server

Options:

--headless - Run browser without UI
--port=9333 - Use custom port (default: 9222)

2. Run Scripts

bun x tsx <<'EOF'
import { connect } from "./src/client.js";

const client = await connect();
const page = await client.page("main");

await page.goto("http://localhost:3000");
await page.fill('[name="email"]', "test@example.com");
await page.click('button[type="submit"]');
await page.screenshot({ path: "/tmp/result.png" });

await client.disconnect();
EOF

API Reference

Client

import { connect } from "./src/client.js";

const client = await connect("http://localhost:9222");

// Page management
const page = await client.page("main");      // Get or create named page
const pages = await client.listPages();       // List all pages
await client.closePage("main");               // Close a page
await client.disconnect();                    // Disconnect (pages persist)

// ARIA snapshots
const snapshot = await client.getAISnapshot("main");
const element = await client.selectSnapshotRef("main", "e5");

Page (Playwright)

// Navigation
await page.goto("https://example.com");
await page.goBack();
await page.reload();

// Locators (recommended)
await page.getByRole("button", { name: "Submit" }).click();
await page.getByLabel("Email").fill("test@example.com");
await page.getByText("Welcome").waitFor();

// CSS selectors
await page.locator(".submit-btn").click();
await page.locator("#email").fill("test@example.com");

// Screenshots
await page.screenshot({ path: "/tmp/page.png" });
await page.screenshot({ path: "/tmp/full.png", fullPage: true });

Wait for Page Load

import { waitForPageLoad } from "./src/client.js";

const result = await waitForPageLoad(page, {
  timeout: 10000,           // Max wait (default: 10s)
  pollInterval: 50,         // Check frequency (default: 50ms)
  minimumWait: 100,         // Initial wait (default: 100ms)
  waitForNetworkIdle: true  // Wait for no pending requests
});

// Result: { success, readyState, pendingRequests, waitTimeMs, timedOut }

Smart filtering ignores:

Ad/tracking domains (Google Analytics, Facebook, Hotjar, etc.)
Non-critical resources after 3s (images, fonts)
Stuck requests (>10s)

Debugging

// Console messages
const logs = await client.getConsoleMessages(page, {
  types: ["error", "warn"],
  limit: 50
});

// Network requests
const requests = await client.getNetworkRequests(page, {
  types: ["xhr", "fetch"]
});

// Performance metrics
const metrics = await client.getPerformanceMetrics(page);
// { lcp, fcp, cls, ttfb, domContentLoaded, load }

// Core Web Vitals
const vitals = await client.getCoreWebVitals(page);
// { lcp, fid, cls, ttfb }

// Performance tracing
await client.startPerformanceTrace(page);
await page.reload();
const trace = await client.stopPerformanceTrace(page);

ARIA Snapshots

const snapshot = await client.getAISnapshot("main");
console.log(snapshot);

Output:

- navigation:
  - link "Home" [ref=e1]
  - link "Products" [ref=e2]
- main:
  - heading "Welcome" [level=1]
  - form:
    - textbox "Email" [ref=e5]
    - button "Submit" [ref=e6]

Interact via refs:

const button = await client.selectSnapshotRef("main", "e6");
await button?.click();

Examples

Form Submission

import { connect, waitForPageLoad } from "./src/client.js";

const client = await connect();
const page = await client.page("main");

await page.goto("http://localhost:3000/login");
await waitForPageLoad(page);

await page.getByLabel("Email").fill("user@example.com");
await page.getByLabel("Password").fill("secret123");
await page.getByRole("button", { name: "Sign In" }).click();

await page.getByText("Welcome").waitFor();
await page.screenshot({ path: "/tmp/logged-in.png" });

await client.disconnect();

Debug Page Issues

import { connect } from "./src/client.js";

const client = await connect();
const page = await client.page("debug");

await page.goto("http://localhost:3000");

const errors = await client.getConsoleMessages(page, { types: ["error"] });
console.log("Errors:", errors);

const requests = await client.getNetworkRequests(page, { types: ["xhr", "fetch"] });
console.log("API calls:", requests);

const vitals = await client.getCoreWebVitals(page);
console.log("Web Vitals:", vitals);

await client.disconnect();

Architecture

├── src/
│   ├── client.ts      # Client: connect, page management, waitForPageLoad
│   ├── server.ts      # Server: persistent browser, REST API
│   ├── devtools.ts    # CDP debugging: console, network, performance
│   ├── types.ts       # Shared TypeScript types
│   └── snapshot/
│       ├── browser-script.ts  # ARIA tree extraction (browser-injected)
│       └── index.ts           # Snapshot injection wrapper
├── scripts/
│   └── start-server.ts        # Server entry point
├── package.json
├── tsconfig.json
└── SKILL.md                   # Claude Code skill documentation

License

MIT