claude-skills-reference/docs/skills/engineering-team/playwright-pro-fix.md

title, description

title	description
Fix Failing or Flaky Tests — Agent Skill & Codex Plugin	Fix failing or flaky Playwright tests. Use when user says 'fix test', 'flaky test', 'test failing', 'debug test', 'test broken', 'test passes. Agent skill for Claude Code, Codex CLI, Gemini CLI, OpenClaw.

Fix Failing or Flaky Tests

:material-code-braces: Engineering - Core :material-identifier: `fix` :material-github: Source

Install: claude /plugin install engineering-skills

Diagnose and fix a Playwright test that fails or passes intermittently using a systematic taxonomy.

Input

$ARGUMENTS contains:

• A test file path: e2e/login.spec.ts
• A test name: ""should redirect after login"`
• A description: "the checkout test fails in CI but passes locally"

Steps

1. Reproduce the Failure

Run the test to capture the error:

npx playwright test <file> --reporter=list

If the test passes, it's likely flaky. Run burn-in:

npx playwright test <file> --repeat-each=10 --reporter=list

If it still passes, try with parallel workers:

npx playwright test --fully-parallel --workers=4 --repeat-each=5

2. Capture Trace

Run with full tracing:

npx playwright test <file> --trace=on --retries=0

Read the trace output. Use /debug to analyze trace files if available.

3. Categorize the Failure

Load flaky-taxonomy.md from this skill directory.

Every failing test falls into one of four categories:

Category	Symptom	Diagnosis
Timing/Async	Fails intermittently everywhere	--repeat-each=20 reproduces locally
Test Isolation	Fails in suite, passes alone	--workers=1 --grep "test name" passes
Environment	Fails in CI, passes locally	Compare CI vs local screenshots/traces
Infrastructure	Random, no pattern	Error references browser internals

4. Apply Targeted Fix

Timing/Async:

• Replace waitForTimeout() with web-first assertions
• Add await to missing Playwright calls
• Wait for specific network responses before asserting
• Use toBeVisible() before interacting with elements

Test Isolation:

• Remove shared mutable state between tests
• Create test data per-test via API or fixtures
• Use unique identifiers (timestamps, random strings) for test data
• Check for database state leaks

Environment:

• Match viewport sizes between local and CI
• Account for font rendering differences in screenshots
• Use docker locally to match CI environment
• Check for timezone-dependent assertions

Infrastructure:

• Increase timeout for slow CI runners
• Add retries in CI config (retries: 2)
• Check for browser OOM (reduce parallel workers)
• Ensure browser dependencies are installed

5. Verify the Fix

Run the test 10 times to confirm stability:

npx playwright test <file> --repeat-each=10 --reporter=list

All 10 must pass. If any fail, go back to step 3.

6. Prevent Recurrence

Suggest:

• Add to CI with retries: 2 if not already
• Enable trace: 'on-first-retry' in config
• Add the fix pattern to project's test conventions doc

Output

• Root cause category and specific issue
• The fix applied (with diff)
• Verification result (10/10 passes)
• Prevention recommendation