Test Fixing Skill for Claude

Test Fixing

Systematically identify and fix all failing tests using smart grouping strategies.

When to Use

• Explicitly asks to fix tests ("fix these tests", "make tests pass")
• Reports test failures ("tests are failing", "test suite is broken")
• Completes implementation and wants tests passing
• Mentions CI/CD failures due to tests

Systematic Approach

1. Initial Test Run

Run make test to identify all failing tests.

Analyze output for:

• Total number of failures
• Error types and patterns
• Affected modules/files

2. Smart Error Grouping

Group similar failures by:

• Error type: ImportError, AttributeError, AssertionError, etc.
• Module/file: Same file causing multiple test failures
• Root cause: Missing dependencies, API changes, refactoring impacts

Prioritize groups by:

• Number of affected tests (highest impact first)
• Dependency order (fix infrastructure before functionality)

3. Systematic Fixing Process

For each group (starting with highest impact):

• Identify root cause
• Read relevant code
• Check recent changes with git diff
• Understand the error pattern

• Implement fix
• Use Edit tool for code changes
• Follow project conventions (see CLAUDE.md)
• Make minimal, focused changes

• Verify fix
• Run subset of tests for this group
• Use pytest markers or file patterns:

     uv run pytest tests/path/to/test_file.py -v
     uv run pytest -k "pattern" -v

• Ensure group passes before moving on

• Move to next group

4. Fix Order Strategy

Infrastructure first:

• Import errors
• Missing dependencies
• Configuration issues

Then API changes:

• Function signature changes
• Module reorganization
• Renamed variables/functions

Finally, logic issues:

• Assertion failures
• Business logic bugs
• Edge case handling

5. Final Verification

After all groups fixed:

• Run complete test suite: make test
• Verify no regressions
• Check test coverage remains intact

Best Practices

• Fix one group at a time
• Run focused tests after each fix
• Use git diff to understand recent changes
• Look for patterns in failures
• Don't move to next group until current passes
• Keep changes minimal and focused

Example Workflow

User: "The tests are failing after my refactor"

• Run make test → 15 failures identified
• Group errors:
• 8 ImportErrors (module renamed)
• 5 AttributeErrors (function signature changed)
• 2 AssertionErrors (logic bugs)
• Fix ImportErrors first → Run subset → Verify
• Fix AttributeErrors → Run subset → Verify
• Fix AssertionErrors → Run subset → Verify
• Run full suite → All pass ✓