Skills

Test Fixing

Debug and fix failing tests systematically with root cause analysis and proper validation.

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Overview

Systematically diagnose and fix failing tests through root cause analysis, understanding test intent, and proper validation.

Key Features

Failure Analysis - Understand why tests are failing
Root Cause Detection - Find the actual problem, not just symptoms
Fix Validation - Ensure fixes address the real issue
Regression Prevention - Prevent similar failures
Test Improvement - Enhance test quality while fixing

Diagnostic Process

1. Reproduce Failure

Run the failing test locally and consistently reproduce it

2. Analyze Error

Examine:

Error messages and stack traces
Expected vs actual values
Test setup and teardown
Dependencies and mocks

3. Identify Root Cause

Determine if failure is due to:

Code regression
Test flakiness
Environment issues
Outdated test expectations
Mock/stub problems

4. Develop Fix

Choose appropriate solution:

Fix the code
Update the test
Fix test setup
Address timing issues
Update dependencies

5. Validate

Ensure fix:

Resolves the failure
Doesn't break other tests
Addresses root cause
Improves overall quality

Common Test Issues

Flaky Tests

Timing/race conditions
Random data dependencies
External service dependencies
Improper cleanup

Broken Tests

Code changes broke functionality
API contract changes
Dependency updates
Environment changes

Bad Tests

Testing implementation, not behavior
Overly coupled to code structure
Missing edge cases
Poor assertions

Best Practices

Understand test intent before fixing
Fix root cause, not symptoms
Run full test suite after fixes
Update related tests if needed
Improve test clarity while fixing
Document non-obvious changes
Consider test isolation
Address flakiness permanently

Validation Checklist