playwright-skill
Complete browser automation with Playwright. Auto-detects dev servers, writes clean test scripts to /tmp. Test pages, fill forms, take screenshots, check responsive design, validate UX, test login flows, check links, automate any browser task. Use when user wants to test websites, automate browser interactions, validate web functionality, or perform any browser-based testing.
Current Project Context
!`ls e2e/*.spec.ts 2>/dev/null || echo 'No e2e test files found'`
Project Conventions (Draft v0)
This project uses @playwright/test with TypeScript. The conventions below take precedence over the generic skill patterns.
Formal Tests (default - use this for real tests)
- Location:
e2e/*.spec.ts - Run:
pnpm test:e2e(headless) orpnpm test:e2e:ui(interactive) - Config:
playwright.config.ts-baseURLishttp://localhost:5173,webServerauto-starts viapnpm dev - No manual server detection needed - the config handles it
- Use relative paths -
page.goto("/")notpage.goto("http://localhost:5173/") - TypeScript only -
.spec.tsfiles, named exports, no raw.jsscripts in the project
New test template:
// e2e/my-feature.spec.ts
import { expect, test } from "@playwright/test";
test("description of what it checks", async ({ page }) => {
await page.goto("/route");
await expect(page.locator("h1")).toBeVisible();
});
Existing example: e2e/home.spec.ts
Ad-hoc Exploration (quick visual checks only)
For rapid one-off checks where you don't need a persistent test, the generic /tmp script approach below still works. Use pnpm test:e2e:ui first - it's usually faster.
IMPORTANT - Path Resolution:
This skill can be installed in different locations (plugin system, manual installation, global, or project-specific). Before executing any commands, determine the skill directory based on where you loaded this SKILL.md file, and use that path in all commands below. Replace $SKILL_DIR with the actual discovered path.
Common installation paths:
- Plugin system:
~/.claude/plugins/marketplaces/playwright-skill/skills/playwright-skill - Manual global:
~/.claude/skills/playwright-skill - Project-specific:
<project>/.claude/skills/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: falseunless 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
See examples/execution-patterns.md for the 3-step execution workflow (detect dev servers, write test script to /tmp, execute from skill directory).
Common Patterns
See examples/common-patterns.md for 6 ready-to-use patterns: responsive testing, login flow, form submission, broken link checking, screenshot with error handling, and responsive design testing.
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 & Custom HTTP Headers
See reference/helpers-headers-guide.md for helper function reference (detectDevServers, safeClick, safeType, takeScreenshot, handleCookieBanner, extractTableData) and custom HTTP header configuration.
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_VALUEenv 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_URLconstant at the top of every script - DEFAULT: Visible browser - Always use
headless: falseunless user explicitly asks for headless mode - Headless mode - Only use
headless: truewhen user specifically requests "headless" or "background" execution - Slow down: Use
slowMo: 100to make actions visible and easier to follow - Wait strategies: Use
waitForURL,waitForSelector,waitForLoadStateinstead 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
/tmpfor 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