Playwright Skill

Playwright Browser Automation

General-purpose browser automation skill. I'll write custom Playwright code for any automation task you request and execute it via the universal executor. CRITICAL WORKFLOW - Follow these steps in order: Auto-detect dev servers - For localhost testing, ALWAYS run server detection FIRST: cd $SKILL_DIR && node -e "require('./lib/helpers').detectDevServers().then(servers => console.log(JSON.stringify(servers)))" If 1 server found: Use it automatically, inform user If multiple servers found: Ask user which one to test If no servers found: Ask for URL or offer to help start dev server Write scripts to /tmp - NEVER write test files to skill directory; always use /tmp/playwright-test-*.js Use visible browser by default - Always use headless: false unless user specifically requests headless mode Parameterize URLs - Always make URLs configurable via environment variable or constant at top of script

How It Works

You describe what you want to test/automate I auto-detect running dev servers (or ask for URL if testing external site) I write custom Playwright code in /tmp/playwright-test-*.js (won't clutter your project) I execute it via: cd $SKILL_DIR && node run.js /tmp/playwright-test-*.js Results displayed in real-time, browser window visible for debugging Test files auto-cleaned from /tmp by your OS

Setup (First Time)

cd $SKILL_DIR npm run setup This installs Playwright and Chromium browser. Only needed once.

Execution Pattern

Step 1: Detect dev servers (for localhost testing) cd $SKILL_DIR && node -e "require('./lib/helpers').detectDevServers().then(s => console.log(JSON.stringify(s)))" Step 2: Write test script to /tmp with URL parameter // /tmp/playwright-test-page.js const { chromium } = require('playwright'); // Parameterized URL (detected or user-provided) const TARGET_URL = 'http://localhost:3001'; // <-- Auto-detected or from user (async () => { const browser = await chromium.launch({ headless: false }); const page = await browser.newPage(); await page.goto(TARGET_URL); console.log('Page loaded:', await page.title()); await page.screenshot({ path: '/tmp/screenshot.png', fullPage: true }); console.log('📸 Screenshot saved to /tmp/screenshot.png'); await browser.close(); })(); Step 3: Execute from skill directory cd $SKILL_DIR && node run.js /tmp/playwright-test-page.js

Test a Page (Multiple Viewports)

// /tmp/playwright-test-responsive.js const { chromium } = require('playwright'); const TARGET_URL = 'http://localhost:3001'; // Auto-detected (async () => { const browser = await chromium.launch({ headless: false, slowMo: 100 }); const page = await browser.newPage(); // Desktop test await page.setViewportSize({ width: 1920, height: 1080 }); await page.goto(TARGET_URL); console.log('Desktop - Title:', await page.title()); await page.screenshot({ path: '/tmp/desktop.png', fullPage: true }); // Mobile test await page.setViewportSize({ width: 375, height: 667 }); await page.screenshot({ path: '/tmp/mobile.png', fullPage: true }); await browser.close(); })();

Test Login Flow

// /tmp/playwright-test-login.js const { chromium } = require('playwright'); const TARGET_URL = 'http://localhost:3001'; // Auto-detected (async () => { const browser = await chromium.launch({ headless: false }); const page = await browser.newPage(); await page.goto(`${TARGET_URL}/login`); await page.fill('input[name="email"]', 'test@example.com'); await page.fill('input[name="password"]', 'password123'); await page.click('button[type="submit"]'); // Wait for redirect await page.waitForURL('**/dashboard'); console.log('✅ Login successful, redirected to dashboard'); await browser.close(); })();

Fill and Submit Form

// /tmp/playwright-test-form.js const { chromium } = require('playwright'); const TARGET_URL = 'http://localhost:3001'; // Auto-detected (async () => { const browser = await chromium.launch({ headless: false, slowMo: 50 }); const page = await browser.newPage(); await page.goto(`${TARGET_URL}/contact`); await page.fill('input[name="name"]', 'John Doe'); await page.fill('input[name="email"]', 'john@example.com'); await page.fill('textarea[name="message"]', 'Test message'); await page.click('button[type="submit"]'); // Verify submission await page.waitForSelector('.success-message'); console.log('✅ Form submitted successfully'); await browser.close(); })();

Check for Broken Links

const { chromium } = require('playwright'); (async () => { const browser = await chromium.launch({ headless: false }); const page = await browser.newPage(); await page.goto('http://localhost:3000'); const links = await page.locator('a[href^="http"]').all(); const results = { working: 0, broken: [] }; for (const link of links) { const href = await link.getAttribute('href'); try { const response = await page.request.head(href); if (response.ok()) { results.working++; } else { results.broken.push({ url: href, status: response.status() }); } } catch (e) { results.broken.push({ url: href, error: e.message }); } } console.log(`✅ Working links: ${results.working}`); console.log(`❌ Broken links:`, results.broken); await browser.close(); })();

Take Screenshot with Error Handling

const { chromium } = require('playwright'); (async () => { const browser = await chromium.launch({ headless: false }); const page = await browser.newPage(); try { await page.goto('http://localhost:3000', { waitUntil: 'networkidle', timeout: 10000, }); await page.screenshot({ path: '/tmp/screenshot.png', fullPage: true, }); console.log('📸 Screenshot saved to /tmp/screenshot.png'); } catch (error) { console.error('❌ Error:', error.message); } finally { await browser.close(); } })();

Test Responsive Design

// /tmp/playwright-test-responsive-full.js const { chromium } = require('playwright'); const TARGET_URL = 'http://localhost:3001'; // Auto-detected (async () => { const browser = await chromium.launch({ headless: false }); const page = await browser.newPage(); const viewports = [ { name: 'Desktop', width: 1920, height: 1080 }, { name: 'Tablet', width: 768, height: 1024 }, { name: 'Mobile', width: 375, height: 667 }, ]; for (const viewport of viewports) { console.log( `Testing ${viewport.name} (${viewport.width}x${viewport.height})`, ); await page.setViewportSize({ width: viewport.width, height: viewport.height, }); await page.goto(TARGET_URL); await page.waitForTimeout(1000); await page.screenshot({ path: `/tmp/${viewport.name.toLowerCase()}.png`, fullPage: true, }); } console.log('✅ All viewports tested'); await browser.close(); })();

Inline Execution (Simple Tasks)

For quick one-off tasks, you can execute code inline without creating files: # Take a quick screenshot cd $SKILL_DIR && node run.js " const browser = await chromium.launch({ headless: false }); const page = await browser.newPage(); await page.goto('http://localhost:3001'); await page.screenshot({ path: '/tmp/quick-screenshot.png', fullPage: true }); console.log('Screenshot saved'); await browser.close(); " When to use inline vs files: Inline: Quick one-off tasks (screenshot, check if element exists, get page title) Files: Complex tests, responsive design checks, anything user might want to re-run

Available Helpers

Optional utility functions in lib/helpers.js: const helpers = require('./lib/helpers'); // Detect running dev servers (CRITICAL - use this first!) const servers = await helpers.detectDevServers(); console.log('Found servers:', servers); // Safe click with retry await helpers.safeClick(page, 'button.submit', { retries: 3 }); // Safe type with clear await helpers.safeType(page, '#username', 'testuser'); // Take timestamped screenshot await helpers.takeScreenshot(page, 'test-result'); // Handle cookie banners await helpers.handleCookieBanner(page); // Extract table data const data = await helpers.extractTableData(page, 'table.results'); See lib/helpers.js for full list.

Custom HTTP Headers

Configure custom headers for all HTTP requests via environment variables. Useful for: Identifying automated traffic to your backend Getting LLM-optimized responses (e.g., plain text errors instead of styled HTML) Adding authentication tokens globally

Configuration

Single header (common case): PW_HEADER_NAME=X-Automated-By PW_HEADER_VALUE=playwright-skill \ cd $SKILL_DIR && node run.js /tmp/my-script.js Multiple headers (JSON format): PW_EXTRA_HEADERS='{"X-Automated-By":"playwright-skill","X-Debug":"true"}' \ cd $SKILL_DIR && node run.js /tmp/my-script.js

How It Works

Headers are automatically applied when using helpers.createContext(): const context = await helpers.createContext(browser); const page = await context.newPage(); // All requests from this page include your custom headers For scripts using raw Playwright API, use the injected getContextOptionsWithHeaders(): const context = await browser.newContext( getContextOptionsWithHeaders({ viewport: { width: 1920, height: 1080 } }), );

Advanced Usage

For comprehensive Playwright API documentation, see API_REFERENCE.md: Selectors & Locators best practices Network interception & API mocking Authentication & session management Visual regression testing Mobile device emulation Performance testing Debugging techniques CI/CD integration

Tips

CRITICAL: Detect servers FIRST - Always run detectDevServers() before writing test code for localhost testing Custom headers - Use PW_HEADER_NAME/PW_HEADER_VALUE env vars to identify automated traffic to your backend Use /tmp for test files - Write to /tmp/playwright-test-*.js, never to skill directory or user's project Parameterize URLs - Put detected/provided URL in a TARGET_URL constant at the top of every script DEFAULT: Visible browser - Always use headless: false unless user explicitly asks for headless mode Headless mode - Only use headless: true when user specifically requests "headless" or "background" execution Slow down: Use slowMo: 100 to make actions visible and easier to follow Wait strategies: Use waitForURL, waitForSelector, waitForLoadState instead of fixed timeouts Error handling: Always use try-catch for robust automation Console output: Use console.log() to track progress and show what's happening

Troubleshooting

Playwright not installed: cd $SKILL_DIR && npm run setup Module not found: Ensure running from skill directory via run.js wrapper Browser doesn't open: Check headless: false and ensure display available Element not found: Add wait: await page.waitForSelector('.element', { timeout: 10000 })

Example Usage

• User: "Test if the marketing page looks good"
• Claude: I'll test the marketing page across multiple viewports. Let me first detect running servers...
• [Runs: detectDevServers()]
• [Output: Found server on port 3001]
• I found your dev server running on http://localhost:3001
• [Writes custom automation script to /tmp/playwright-test-marketing.js with URL parameterized]
• [Runs: cd $SKILL_DIR && node run.js /tmp/playwright-test-marketing.js]
• [Shows results with screenshots from /tmp/]
• User: "Check if login redirects correctly"
• Claude: I'll test the login flow. First, let me check for running servers...
• [Runs: detectDevServers()]
• [Output: Found servers on ports 3000 and 3001]
• I found 2 dev servers. Which one should I test?
• http://localhost:3000
• http://localhost:3001
• User: "Use 3001"
• [Writes login automation to /tmp/playwright-test-login.js]
• [Runs: cd $SKILL_DIR && node run.js /tmp/playwright-test-login.js]
• [Reports: ✅ Login successful, redirected to /dashboard]

Notes

Each automation is custom-written for your specific request Not limited to pre-built scripts - any browser task possible Auto-detects running dev servers to eliminate hardcoded URLs Test scripts written to /tmp for automatic cleanup (no clutter) Code executes reliably with proper module resolution via run.js Progressive disclosure - API_REFERENCE.md loaded only when advanced features needed