browser-automation

browser-automation

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Browser automation powers web testing, scraping, and AI agent

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Updated 7/15/2026
SKILL.md
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name
browser-automation
description

Browser automation powers web testing, scraping, and AI agent

Browser Automation

Browser automation powers web testing, scraping, and AI agent interactions.
The difference between a flaky script and a reliable system comes down to
understanding selectors, waiting strategies, and anti-detection patterns.

This skill covers Playwright (recommended) and Puppeteer, with patterns for
testing, scraping, and agentic browser control. Key insight: Playwright won
the framework war. Unless you need Puppeteer's stealth ecosystem or are
Chrome-only, Playwright is the better choice in 2025.

Critical distinction: Testing automation (predictable apps you control) vs
scraping/agent automation (unpredictable sites that fight back). Different
problems, different solutions.

Principles

  • Use user-facing locators (getByRole, getByText) over CSS/XPath
  • Never add manual waits - Playwright's auto-wait handles it
  • Each test/task should be fully isolated with fresh context
  • Screenshots and traces are your debugging lifeline
  • Headless for CI, headed for debugging
  • Anti-detection is cat-and-mouse - stay current or get blocked

Capabilities

  • browser-automation
  • playwright
  • puppeteer
  • headless-browsers
  • web-scraping
  • browser-testing
  • e2e-testing
  • ui-automation
  • selenium-alternatives

Scope

  • api-testing → backend
  • load-testing → performance-thinker
  • accessibility-testing → accessibility-specialist
  • visual-regression-testing → ui-design

Tooling

Frameworks

  • Playwright - When: Default choice - cross-browser, auto-waiting, best DX Note: 96% success rate, 4.5s avg execution, Microsoft-backed
  • Puppeteer - When: Chrome-only, need stealth plugins, existing codebase Note: 75% success rate at scale, but best stealth ecosystem
  • Selenium - When: Legacy systems, specific language bindings Note: Slower, more verbose, but widest browser support

Stealth_tools

  • puppeteer-extra-plugin-stealth - When: Need to bypass bot detection with Puppeteer Note: Gold standard for anti-detection
  • playwright-extra - When: Stealth plugins for Playwright Note: Port of puppeteer-extra ecosystem
  • undetected-chromedriver - When: Selenium anti-detection Note: Dynamic bypass of detection

Cloud_browsers

  • Browserbase - When: Managed headless infrastructure Note: Built-in stealth mode, session management
  • BrowserStack - When: Cross-browser testing at scale Note: Real devices, CI integration

Patterns

Test Isolation Pattern

Each test runs in complete isolation with fresh state

When to use: Testing, any automation that needs reproducibility

TEST ISOLATION:

"""
Each test gets its own:

  • Browser context (cookies, storage)
  • Fresh page
  • Clean state
    """

Playwright Test Example

"""
import { test, expect } from '@playwright/test';

// Each test runs in isolated browser context
test('user can add item to cart', async ({ page }) => {
// Fresh context - no cookies, no storage from other tests
await page.goto('/products');
await page.getByRole('button', { name: 'Add to Cart' }).click();
await expect(page.getByTestId('cart-count')).toHaveText('1');
});

test('user can remove item from cart', async ({ page }) => {
// Completely isolated - cart is empty
await page.goto('/cart');
await expect(page.getByText('Your cart is empty')).toBeVisible();
});
"""

Shared Authentication Pattern

"""
// Save auth state once, reuse across tests
// setup.ts
import { test as setup } from '@playwright/test';

setup('authenticate', async ({ page }) => {
await page.goto('/login');
await page.getByLabel('Email').fill('user@example.com');
await page.getByLabel('Password').fill('password');
await page.getByRole('button', { name: 'Sign in' }).click();

// Wait for auth to complete
await page.waitForURL('/dashboard');

// Save authentication state
await page.context().storageState({
path: './playwright/.auth/user.json'
});
});

// playwright.config.ts
export default defineConfig({
projects: [
{ name: 'setup', testMatch: /.*.setup.ts/ },
{
name: 'tests',
dependencies: ['setup'],
use: {
storageState: './playwright/.auth/user.json',
},
},
],
});
"""

User-Facing Locator Pattern

Select elements the way users see them

When to use: Always - the default approach for selectors

USER-FACING LOCATORS:

"""
Priority order:

  1. getByRole - Best: matches accessibility tree
  2. getByText - Good: matches visible content
  3. getByLabel - Good: matches form labels
  4. getByTestId - Fallback: explicit test contracts
  5. CSS/XPath - Last resort: fragile, avoid
    """

Good Examples (User-Facing)

"""
// By role - THE BEST CHOICE
await page.getByRole('button', { name: 'Submit' }).click();
await page.getByRole('link', { name: 'Sign up' }).click();
await page.getByRole('heading', { name: 'Dashboard' }).isVisible();
await page.getByRole('textbox', { name: 'Search' }).fill('query');

// By text content
await page.getByText('Welcome back').isVisible();
await page.getByText(/Order #\d+/).click(); // Regex supported

// By label (forms)
await page.getByLabel('Email address').fill('user@example.com');
await page.getByLabel('Password').fill('secret');

// By placeholder
await page.getByPlaceholder('Search...').fill('query');

// By test ID (when no user-facing option works)
await page.getByTestId('submit-button').click();
"""

Bad Examples (Fragile)

"""
// DON'T - CSS selectors tied to structure
await page.locator('.btn-primary.submit-form').click();
await page.locator('#header > div > button:nth-child(2)').click();

// DON'T - XPath tied to structure
await page.locator('//div[@class="form"]/button[1]').click();

// DON'T - Auto-generated selectors
await page.locator('[data-v-12345]').click();
"""

Filtering and Chaining

"""
// Filter by containing text
await page.getByRole('listitem')
.filter({ hasText: 'Product A' })
.getByRole('button', { name: 'Add to cart' })
.click();

// Filter by NOT containing
await page.getByRole('listitem')
.filter({ hasNotText: 'Sold out' })
.first()
.click();

// Chain locators
const row = page.getByRole('row', { name: 'John Doe' });
await row.getByRole('button', { name: 'Edit' }).click();
"""

Auto-Wait Pattern

Let Playwright wait automatically, never add manual waits

When to use: Always with Playwright

AUTO-WAIT PATTERN:

"""
Playwright waits automatically for:

  • Element to be attached to DOM
  • Element to be visible
  • Element to be stable (not animating)
  • Element to receive events
  • Element to be enabled

NEVER add manual waits!
"""

Wrong - Manual Waits

"""
// DON'T DO THIS
await page.goto('/dashboard');
await page.waitForTimeout(2000); // NO! Arbitrary wait
await page.click('.submit-button');

// DON'T DO THIS
await page.waitForSelector('.loading-spinner', { state: 'hidden' });
await page.waitForTimeout(500); // "Just to be safe" - NO!
"""

Correct - Let Auto-Wait Work

"""
// Auto-waits for button to be clickable
await page.getByRole('button', { name: 'Submit' }).click();

// Auto-waits for text to appear
await expect(page.getByText('Success!')).toBeVisible();

// Auto-waits for navigation to complete
await page.goto('/dashboard');
// Page is ready - no manual wait needed
"""

When You DO Need to Wait

"""
// Wait for specific network request
const responsePromise = page.waitForResponse(
response => response.url().includes('/api/data')
);
await page.getByRole('button', { name: 'Load' }).click();
const response = await responsePromise;

// Wait for URL change
await Promise.all([
page.waitForURL('**/dashboard'),
page.getByRole('button', { name: 'Login' }).click(),
]);

// Wait for download
const downloadPromise = page.waitForEvent('download');
await page.getByText('Export CSV').click();
const download = await downloadPromise;
"""

Stealth Browser Pattern

Avoid bot detection for scraping

When to use: Scraping sites with anti-bot protection

STEALTH BROWSER PATTERN:

"""
Bot detection checks for:

  • navigator.webdriver property
  • Chrome DevTools protocol artifacts
  • Browser fingerprint inconsistencies
  • Behavioral patterns (perfect timing, no mouse movement)
  • Headless indicators
    """

Puppeteer Stealth (Best Anti-Detection)

"""
import puppeteer from 'puppeteer-extra';
import StealthPlugin from 'puppeteer-extra-plugin-stealth';

puppeteer.use(StealthPlugin());

const browser = await puppeteer.launch({
headless: 'new',
args: [
'--no-sandbox',
'--disable-setuid-sandbox',
'--disable-blink-features=AutomationControlled',
],
});

const page = await browser.newPage();

// Set realistic viewport
await page.setViewport({ width: 1920, height: 1080 });

// Realistic user agent
await page.setUserAgent(
'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 ' +
'(KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36'
);

// Navigate with human-like behavior
await page.goto('https://target-site.com', {
waitUntil: 'networkidle0',
});
"""

Playwright Stealth

"""
import { chromium } from 'playwright-extra';
import stealth from 'puppeteer-extra-plugin-stealth';

chromium.use(stealth());

const browser = await chromium.launch({ headless: true });
const context = await browser.newContext({
viewport: { width: 1920, height: 1080 },
userAgent: 'Mozilla/5.0 ...',
locale: 'en-US',
timezoneId: 'America/New_York',
});
"""

Human-Like Behavior

"""
// Random delays between actions
const randomDelay = (min: number, max: number) =>
new Promise(r => setTimeout(r, Math.random() * (max - min) + min));

await page.goto(url);
await randomDelay(500, 1500);

// Mouse movement before click
const button = await page.$('button.submit');
const box = await button.boundingBox();
await page.mouse.move(
box.x + box.width / 2,
box.y + box.height / 2,
{ steps: 10 } // Move in steps like a human
);
await randomDelay(100, 300);
await button.click();

// Scroll naturally
await page.evaluate(() => {
window.scrollBy({
top: 300 + Math.random() * 200,
behavior: 'smooth'
});
});
"""

Error Recovery Pattern

Handle failures gracefully with screenshots and retries

When to use: Any production automation

ERROR RECOVERY PATTERN:

Automatic Screenshot on Failure

"""
// playwright.config.ts
export default defineConfig({
use: {
screenshot: 'only-on-failure',
trace: 'retain-on-failure',
video: 'retain-on-failure',
},
retries: 2, // Retry failed tests
});
"""

Try-Catch with Debug Info

"""
async function scrapeProduct(page: Page, url: string) {
try {
await page.goto(url, { timeout: 30000 });

const title = await page.getByRole('heading', { level: 1 }).textContent();
const price = await page.getByTestId('price').textContent();

return { title, price, success: true };

} catch (error) {
// Capture debug info
const screenshot = await page.screenshot({
path: errors/${Date.now()}-error.png,
fullPage: true
});

const html = await page.content();
await fs.writeFile(`errors/${Date.now()}-page.html`, html);

console.error({
  url,
  error: error.message,
  currentUrl: page.url(),
});

return { success: false, error: error.message };

}
}
"""

Retry with Exponential Backoff

"""
async function withRetry<T>(
fn: () => Promise<T>,
maxRetries = 3,
baseDelay = 1000
): Promise<T> {
let lastError: Error;

for (let attempt = 0; attempt < maxRetries; attempt++) {
try {
return await fn();
} catch (error) {
lastError = error;

  if (attempt < maxRetries - 1) {
    const delay = baseDelay * Math.pow(2, attempt);
    const jitter = delay * 0.1 * Math.random();
    await new Promise(r => setTimeout(r, delay + jitter));
  }
}

}

throw lastError;
}

// Usage
const result = await withRetry(
() => scrapeProduct(page, url),
3,
2000
);
"""

Parallel Execution Pattern

Run tests/tasks in parallel for speed

When to use: Multiple independent pages or tests

PARALLEL EXECUTION:

Playwright Test Parallelization

"""
// playwright.config.ts
export default defineConfig({
fullyParallel: true,
workers: process.env.CI ? 4 : undefined, // CI: 4 workers, local: CPU-based

projects: [
{ name: 'chromium', use: { ...devices['Desktop Chrome'] } },
{ name: 'firefox', use: { ...devices['Desktop Firefox'] } },
{ name: 'webkit', use: { ...devices['Desktop Safari'] } },
],
});
"""

Browser Contexts for Parallel Scraping

"""
const browser = await chromium.launch();

const urls = ['url1', 'url2', 'url3', 'url4', 'url5'];

// Create multiple contexts - each is isolated
const results = await Promise.all(
urls.map(async (url) => {
const context = await browser.newContext();
const page = await context.newPage();

try {
  await page.goto(url);
  const data = await extractData(page);
  return { url, data, success: true };
} catch (error) {
  return { url, error: error.message, success: false };
} finally {
  await context.close();
}

})
);

await browser.close();
"""

Rate-Limited Parallel Processing

"""
import pLimit from 'p-limit';

const limit = pLimit(5); // Max 5 concurrent

const results = await Promise.all(
urls.map(url => limit(async () => {
const context = await browser.newContext();
const page = await context.newPage();

// Random delay between requests
await new Promise(r => setTimeout(r, Math.random() * 2000));

try {
  return await scrapePage(page, url);
} finally {
  await context.close();
}

}))
);
"""

Network Interception Pattern

Mock, block, or modify network requests

When to use: Testing, blocking ads/analytics, modifying responses

NETWORK INTERCEPTION:

Block Unnecessary Resources

"""
await page.route('**/*', (route) => {
const url = route.request().url();
const resourceType = route.request().resourceType();

// Block images, fonts, analytics for faster scraping
if (['image', 'font', 'media'].includes(resourceType)) {
return route.abort();
}

// Block tracking/analytics
if (url.includes('google-analytics') ||
url.includes('facebook.com/tr')) {
return route.abort();
}

return route.continue();
});
"""

Mock API Responses (Testing)

"""
await page.route('**/api/products', async (route) => {
await route.fulfill({
status: 200,
contentType: 'application/json',
body: JSON.stringify([
{ id: 1, name: 'Mock Product', price: 99.99 },
]),
});
});

// Now page will receive mocked data
await page.goto('/products');
"""

Capture API Responses

"""
const apiResponses: any[] = [];

page.on('response', async (response) => {
if (response.url().includes('/api/')) {
const data = await response.json().catch(() => null);
apiResponses.push({
url: response.url(),
status: response.status(),
data,
});
}
});

await page.goto('/dashboard');
// apiResponses now contains all API calls
"""

Sharp Edges

Using waitForTimeout Instead of Proper Waits

Severity: CRITICAL

Situation: Waiting for elements or page state

Symptoms:
Tests pass locally, fail in CI. Pass 9 times, fail on the 10th.
"Element not found" errors that seem random. Tests take 30+ seconds
when they should take 3.

Why this breaks:
waitForTimeout is a fixed delay. If the page loads in 500ms, you wait
2000ms anyway. If the page takes 2100ms (CI is slower), you fail.
There's no correct value - it's always either too short or too long.

Recommended fix:

REMOVE all waitForTimeout calls

WRONG:

await page.goto('/dashboard');
await page.waitForTimeout(2000); # Arbitrary!
await page.click('.submit');

CORRECT - Auto-wait handles it:

await page.goto('/dashboard');
await page.getByRole('button', { name: 'Submit' }).click();

If you need to wait for specific condition:

await expect(page.getByText('Dashboard')).toBeVisible();
await page.waitForURL('**/dashboard');
await page.waitForResponse(resp => resp.url().includes('/api/data'));

For animations, wait for element to be stable:

await page.getByRole('button').click(); # Auto-waits for stable

NEVER use setTimeout or waitForTimeout in production code

CSS Selectors Tied to Styling Classes

Severity: HIGH

Situation: Selecting elements for interaction

Symptoms:
Tests break after CSS refactoring. Selectors like .btn-primary stop
working. Frontend redesign breaks all tests without changing behavior.

Why this breaks:
CSS class names are implementation details for styling, not semantic
meaning. When designers change from .btn-primary to .button--primary,
your tests break even though behavior is identical.

Recommended fix:

Use user-facing locators instead:

WRONG - Tied to CSS:

await page.locator('.btn-primary.submit-form').click();
await page.locator('#sidebar > div.menu > ul > li:nth-child(3)').click();

CORRECT - User-facing:

await page.getByRole('button', { name: 'Submit' }).click();
await page.getByRole('menuitem', { name: 'Settings' }).click();

If you must use CSS, use data-testid:

<button data-testid="submit-order">Submit</button>

await page.getByTestId('submit-order').click();

Locator priority:

1. getByRole - matches accessibility

2. getByText - matches visible content

3. getByLabel - matches form labels

4. getByTestId - explicit test contract

5. CSS/XPath - last resort only

navigator.webdriver Exposes Automation

Severity: HIGH

Situation: Scraping sites with bot detection

Symptoms:
Immediate 403 errors. CAPTCHA challenges. Empty pages. "Access Denied"
messages. Works for 1 request, then gets blocked.

Why this breaks:
By default, headless browsers set navigator.webdriver = true. This is
the first thing bot detection checks. It's a bright red flag that
says "I'm automated."

Recommended fix:

Use stealth plugins:

Puppeteer Stealth (best option):

import puppeteer from 'puppeteer-extra';
import StealthPlugin from 'puppeteer-extra-plugin-stealth';

puppeteer.use(StealthPlugin());

const browser = await puppeteer.launch({
headless: 'new',
args: ['--disable-blink-features=AutomationControlled'],
});

Playwright Stealth:

import { chromium } from 'playwright-extra';
import stealth from 'puppeteer-extra-plugin-stealth';

chromium.use(stealth());

Manual (partial):

await page.evaluateOnNewDocument(() => {
Object.defineProperty(navigator, 'webdriver', {
get: () => undefined,
});
});

Note: This is cat-and-mouse. Detection evolves.

For serious scraping, consider managed solutions like Browserbase.

Tests Share State and Affect Each Other

Severity: HIGH

Situation: Running multiple tests in sequence

Symptoms:
Tests pass individually but fail when run together. Order matters -
test B fails if test A runs first. Random failures that "fix themselves"
on rerun.

Why this breaks:
Shared browser context means shared cookies, localStorage, and session
state. Test A logs in, test B expects logged-out state. Test A adds
item to cart, test B's cart count is wrong.

Recommended fix:

Each test must be fully isolated:

Playwright Test (automatic isolation):

test('first test', async ({ page }) => {
// Fresh context, fresh page
});

test('second test', async ({ page }) => {
// Completely isolated from first test
});

Manual isolation:

const context = await browser.newContext(); // Fresh context
const page = await context.newPage();
// ... test code ...
await context.close(); // Clean up

Shared authentication (the right way):

// 1. Save auth state to file
await context.storageState({ path: './auth.json' });

// 2. Reuse in other tests
const context = await browser.newContext({
storageState: './auth.json'
});

Never modify global state in tests

Never rely on previous test's actions

No Trace Capture for CI Failures

Severity: MEDIUM

Situation: Debugging test failures in CI

Symptoms:
"Test failed in CI" with no useful information. Can't reproduce
locally. Screenshot shows page but not what went wrong. Guessing
at root cause.

Why this breaks:
CI runs headless on different hardware. Timing is different. Network
is different. Without traces, you can't see what actually happened -
the sequence of actions, network requests, console logs.

Recommended fix:

Enable traces for failures:

playwright.config.ts:

export default defineConfig({
use: {
trace: 'retain-on-failure', # Keep trace on failure
screenshot: 'only-on-failure', # Screenshot on failure
video: 'retain-on-failure', # Video on failure
},
outputDir: './test-results',
});

View trace locally:

npx playwright show-trace test-results/path/to/trace.zip

In CI, upload test-results as artifact:

GitHub Actions:

  • uses: actions/upload-artifact@v3
    if: failure()
    with:
    name: playwright-traces
    path: test-results/

Trace shows:

- Timeline of actions

- Screenshots at each step

- Network requests and responses

- Console logs

- DOM snapshots

Tests Pass Headed but Fail Headless

Severity: MEDIUM

Situation: Running tests in headless mode for CI

Symptoms:
Works perfectly when you watch it. Fails mysteriously in CI.
"Element not visible" in headless but visible in headed mode.

Why this breaks:
Headless browsers have no display, which affects some CSS (visibility
calculations), viewport sizing, and font rendering. Some animations
behave differently. Popup windows may not work.

Recommended fix:

Set consistent viewport:

const browser = await chromium.launch({
headless: true,
});

const context = await browser.newContext({
viewport: { width: 1280, height: 720 },
});

Or in config:

export default defineConfig({
use: {
viewport: { width: 1280, height: 720 },
},
});

Debug headless failures:

1. Run with headed mode locally

npx playwright test --headed

2. Slow down to watch

npx playwright test --headed --slowmo 100

3. Use trace viewer for CI failures

npx playwright show-trace trace.zip

4. For stubborn issues, screenshot at failure point:

await page.screenshot({ path: 'debug.png', fullPage: true });

Getting Blocked by Rate Limiting

Severity: HIGH

Situation: Scraping multiple pages quickly

Symptoms:
Works for first 50 pages, then 429 errors. Suddenly all requests fail.
IP gets blocked. CAPTCHA starts appearing after successful requests.

Why this breaks:
Sites monitor request patterns. 100 requests per second from one IP
is obviously automated. Rate limits protect servers and catch scrapers.

Recommended fix:

Add delays between requests:

const randomDelay = () =>
new Promise(r => setTimeout(r, 1000 + Math.random() * 2000));

for (const url of urls) {
await randomDelay(); // 1-3 second delay
await page.goto(url);
// ... scrape ...
}

Use rotating proxies:

const proxies = ['http://proxy1:8080', 'http://proxy2:8080'];
let proxyIndex = 0;

const getNextProxy = () => proxies[proxyIndex++ % proxies.length];

const context = await browser.newContext({
proxy: { server: getNextProxy() },
});

Limit concurrent requests:

import pLimit from 'p-limit';
const limit = pLimit(3); // Max 3 concurrent

await Promise.all(
urls.map(url => limit(() => scrapePage(url)))
);

Rotate user agents:

const userAgents = [
'Mozilla/5.0 (Windows...',
'Mozilla/5.0 (Macintosh...',
];

await page.setExtraHTTPHeaders({
'User-Agent': userAgents[Math.floor(Math.random() * userAgents.length)]
});

New Windows/Popups Not Handled

Severity: MEDIUM

Situation: Clicking links that open new windows

Symptoms:
Click button, nothing happens. Test hangs. "Window not found" errors.
Actions succeed but verification fails because you're on wrong page.

Why this breaks:
target="_blank" links open new windows. Your page reference still
points to the original page. The new window exists but you're not
listening for it.

Recommended fix:

Wait for popup BEFORE triggering it:

New window/tab:

const pagePromise = context.waitForEvent('page');
await page.getByRole('link', { name: 'Open in new tab' }).click();
const newPage = await pagePromise;
await newPage.waitForLoadState();

// Now interact with new page
await expect(newPage.getByRole('heading')).toBeVisible();

// Close when done
await newPage.close();

Popup windows:

const popupPromise = page.waitForEvent('popup');
await page.getByRole('button', { name: 'Open popup' }).click();
const popup = await popupPromise;
await popup.waitForLoadState();

Multiple windows:

const pages = context.pages(); // Get all open pages

Can't Interact with Elements in iframes

Severity: MEDIUM

Situation: Page contains embedded iframes

Symptoms:
Element clearly visible but "not found". Selector works in DevTools
but not in Playwright. Parent page selectors work, iframe content
doesn't.

Why this breaks:
iframes are separate documents. page.locator only searches the main
frame. You need to explicitly get the iframe's frame to interact
with its contents.

Recommended fix:

Get frame by name or selector:

By frame name:

const frame = page.frame('payment-iframe');
await frame.getByRole('textbox', { name: 'Card number' }).fill('4242...');

By selector:

const frame = page.frameLocator('iframe#payment');
await frame.getByRole('textbox', { name: 'Card number' }).fill('4242...');

Nested iframes:

const outer = page.frameLocator('iframe#outer');
const inner = outer.frameLocator('iframe#inner');
await inner.getByRole('button').click();

Wait for iframe to load:

await page.waitForSelector('iframe#payment');
const frame = page.frameLocator('iframe#payment');
await frame.getByText('Secure Payment').waitFor();

Validation Checks

Using waitForTimeout

Severity: ERROR

waitForTimeout causes flaky tests and slow execution

Message: Using waitForTimeout - remove it. Playwright auto-waits for elements. Use waitForResponse, waitForURL, or assertions instead.

Using setTimeout in Test Code

Severity: WARNING

setTimeout is unreliable for timing in tests

Message: Using setTimeout instead of Playwright waits. Replace with await expect(...).toBeVisible() or page.waitFor*.

Custom Sleep Function

Severity: WARNING

Sleep functions indicate improper waiting strategy

Message: Custom sleep function detected. Use Playwright's built-in waiting mechanisms instead.

CSS Class Selector Used

Severity: WARNING

CSS class selectors are fragile

Message: Using CSS class selector. Prefer getByRole, getByText, getByLabel, or getByTestId for more stable selectors.

nth-child CSS Selector

Severity: WARNING

Position-based selectors are very fragile

Message: Using position-based selector. These break when DOM order changes. Use user-facing locators instead.

XPath Selector Used

Severity: INFO

XPath should be last resort

Message: Using XPath selector. Consider getByRole, getByText first. XPath should be last resort for complex DOM traversal.

Auto-Generated Selector

Severity: WARNING

Framework-generated selectors are extremely fragile

Message: Using auto-generated selector. These change on every build. Use data-testid instead.

Puppeteer Without Stealth Plugin

Severity: INFO

Scraping without stealth is easily detected

Message: Using Puppeteer without stealth plugin. Consider puppeteer-extra-plugin-stealth for anti-detection.

navigator.webdriver Not Hidden

Severity: INFO

navigator.webdriver exposes automation

Message: Launching browser without hiding automation flags. For scraping, add stealth measures.

Scraping Loop Without Error Handling

Severity: WARNING

One failure shouldn't crash entire scrape

Message: Scraping loop without try/catch. One page failure will crash the entire scrape. Add error handling.

Collaboration

Delegation Triggers

  • user needs full desktop control beyond browser -> computer-use-agents (Desktop automation for non-browser apps)
  • user needs API testing alongside browser tests -> backend (API integration and testing patterns)
  • user needs testing strategy -> test-architect (Overall test architecture decisions)
  • user needs visual regression testing -> ui-design (Visual comparison and design validation)
  • user needs browser automation in workflows -> workflow-automation (Durable execution for browser tasks)
  • user building browser tools for agents -> agent-tool-builder (Tool design patterns for LLM agents)

Related Skills

Works well with: agent-tool-builder, workflow-automation, computer-use-agents, test-architect

When to Use

  • User mentions or implies: playwright
  • User mentions or implies: puppeteer
  • User mentions or implies: browser automation
  • User mentions or implies: headless
  • User mentions or implies: web scraping
  • User mentions or implies: e2e test
  • User mentions or implies: end-to-end
  • User mentions or implies: selenium
  • User mentions or implies: chromium
  • User mentions or implies: browser test
  • User mentions or implies: page.click
  • User mentions or implies: locator

Limitations

  • Use this skill only when the task clearly matches the scope described above.
  • Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
  • Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.