TDD Failure Recovery

Version: {{VERSION}}

When to Use

• •RED phase test passes unexpectedly (should fail)
• •GREEN phase test still fails (should pass)
• •REFACTOR phase breaks tests (should stay green)
• •Tests behave unpredictably or inconsistently

Scenario 1: RED Phase Test Passes Unexpectedly

Possible causes:

1. •Feature already exists
2. •Test is too permissive
3. •Test setup incorrect

Recovery:

1. •Add intentional failure to verify test can fail
2. •Check for existing implementation
3. •Review test logic
4. •Revise test and verify it fails
5. •Resume TDD cycle

Scenario 2: GREEN Phase Test Still Fails

Possible causes:

1. •Implementation incomplete
2. •Implementation has bugs
3. •Test expectations misunderstood

Recovery:

1. •Read failure message carefully
2. •Verify implementation code
3. •Check test requirements
4. •Revise implementation
5. •Run full test suite
6. •Resume TDD cycle

Scenario 3: REFACTOR Phase Breaks Tests

Possible causes:

1. •Behavioral change introduced
2. •Breaking change in API
3. •Incomplete refactoring
4. •Test dependency on implementation

Recovery:

1. •IMMEDIATE ROLLBACK
2. •Analyze what broke
3. •Decide: Skip, smaller refactoring, or fix test

Critical principle:

TESTS MUST STAY GREEN
If refactoring breaks tests -> ROLLBACK
Do not proceed with broken tests

Scenario 4: Rollback Procedure

1. •Identify changes to undo
2. •Restore previous code version
3. •Verify file state matches pre-change
4. •Run full test suite
5. •Verify all tests GREEN

Scenario 5: Inconsistent Test Results

Possible causes:

1. •Test order dependency
2. •Timing issues
3. •External dependencies
4. •Random data in tests

Recovery:

1. •Run failing test alone
2. •Check test isolation
3. •Fix with proper setup/teardown
4. •Verify consistency

Diagnostic Flowchart

Test failed unexpectedly -> What phase?

RED: Should fail but passes -> Test invalid, revise test
GREEN: Should pass but fails -> Implementation incomplete, revise impl
REFACTOR: Should stay green but fails -> ROLLBACK immediately

Prevention Strategies

1. •Verify Each Phase - Never assume, always run tests
2. •Clear Communication - Report exact results
3. •Maintain Green State - Tests green except during RED phase

Common Recovery Patterns

Resources

• •resources/failure-diagnostic-flowchart.md
• •resources/recovery-procedures.md
• •resources/test-isolation-guide.md

End of TDD Failure Recovery Skill