/fix

name: "fix"
description: >-
  Fix failing or flaky Playwright tests. Use when user says "fix test",
  "flaky test", "test failing", "debug test", "test broken", "test passes
  sometimes", or "intermittent failure".

Fix Failing or Flaky Tests

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