Test Sync Skill

Purpose

Maintain alignment between test files and source code. Detect orphaned tests (code deleted but tests remain), missing tests, and implementation-coupled tests. Based on UTRefactor research showing automated test maintenance can achieve 89% smell reduction.

Research Foundation

Concept	Source	Reference
Test Refactoring	UTRefactor (ACM 2024)	89% smell reduction
Test Smells	Meszaros (2007)	"xUnit Test Patterns"
Test-Code Traceability	IEEE TSE	Test maintenance research

When This Skill Applies

• After major refactoring
• During test suite health audits
• When tests fail for deleted code
• Before releases (cleanup validation)
• When test count seems disconnected from codebase

Trigger Phrases

Natural Language	Action
"Find orphaned tests"	Detect tests for deleted code
"Sync tests with code"	Full alignment analysis
"Are my tests up to date?"	Test-code sync check
"Clean up test suite"	Find removable tests
"Test coverage gaps"	Find missing tests

Sync Analysis Types

1. Orphaned Test Detection

Tests that reference deleted or renamed code:

def find_orphaned_tests(project_dir):
    """Find tests for code that no longer exists"""
    orphans = []

    for test_file in glob(f"{project_dir}/test/**/*.test.ts"):
        # Extract tested module from import/path
        tested_module = infer_tested_module(test_file)

        if not exists(tested_module):
            orphans.append({
                "test_file": test_file,
                "expected_source": tested_module,
                "status": "source_deleted"
            })

        # Check for unused test helpers
        for helper in extract_test_helpers(test_file):
            if not is_used_in_assertions(test_file, helper):
                orphans.append({
                    "test_file": test_file,
                    "item": helper,
                    "status": "unused_helper"
                })

    return orphans

2. Missing Test Detection

Source files without corresponding tests:

def find_missing_tests(project_dir):
    """Find source files without tests"""
    missing = []

    for src_file in glob(f"{project_dir}/src/**/*.ts"):
        if is_testable(src_file):  # Exclude types, index files
            test_file = get_test_path(src_file)
            if not exists(test_file):
                missing.append({
                    "source": src_file,
                    "expected_test": test_file,
                    "functions": extract_public_functions(src_file),
                    "priority": assess_priority(src_file)
                })

    return missing

3. Implementation-Coupled Test Detection

Tests that test implementation details rather than behavior:

COUPLING_PATTERNS = [
    # Testing private methods
    (r'\.\_\w+\(', "Tests private method"),

    # Testing internal state
    (r'\.__\w+', "Accesses internal state"),

    # Mocking too deeply
    (r'mock.*mock.*mock', "Over-mocking"),

    # Testing exact implementation
    (r'toHaveBeenCalledWith.*\{.*\{', "Assertion on implementation details"),
]

def find_coupled_tests(test_file):
    """Detect implementation-coupled tests"""
    content = read_file(test_file)
    issues = []

    for pattern, description in COUPLING_PATTERNS:
        matches = re.findall(pattern, content)
        if matches:
            issues.append({
                "pattern": pattern,
                "description": description,
                "count": len(matches),
                "risk": "Tests may break on safe refactors"
            })

    return issues

4. Test-Code Mapping

Verify traceability between tests and source:

def build_test_map(project_dir):
    """Build mapping of tests to source files"""
    mapping = {}

    for test_file in glob(f"{project_dir}/test/**/*.test.ts"):
        source_file = infer_source(test_file)
        imports = extract_imports(test_file)

        mapping[test_file] = {
            "inferred_source": source_file,
            "actual_imports": imports,
            "coverage": get_coverage_for(test_file),
            "alignment": "aligned" if source_file in imports else "misaligned"
        }

    return mapping

Output Format

## Test Sync Report

**Project**: my-project
**Analysis Date**: 2024-12-12
**Test Files**: 45
**Source Files**: 78

### Summary

| Category | Count | Action |
|----------|-------|--------|
| Orphaned tests | 3 | Delete |
| Missing tests | 8 | Create |
| Implementation-coupled | 5 | Refactor |
| Aligned | 37 | None |

### Orphaned Tests (Safe to Delete)

#### 1. `test/auth/legacy-login.test.ts`
**Status**: Source deleted
**Original Source**: `src/auth/legacy-login.ts` (deleted in commit abc123)
**Last Modified**: 45 days ago
**Action**: DELETE

```bash
rm test/auth/legacy-login.test.ts

2.

test/utils/string-helpers.test.ts

Status: Function removed Details: Tests

formatCurrency()

which was removed Action: DELETE specific test, keep file

// Remove this test block:
describe('formatCurrency', () => { ... });

Missing Tests (Should Create)

1.

src/payment/processor.ts

(HIGH PRIORITY)

Reason: Payment processing - critical path Public Functions:

• processPayment(amount, method)

  - No test

• refundPayment(transactionId)

  - No test

• validateCard(cardInfo)

  - No test

Suggested Test File:

test/payment/processor.test.ts

// Scaffold
describe('PaymentProcessor', () => {
  describe('processPayment', () => {
    it('should process valid payment');
    it('should reject insufficient funds');
    it('should handle network errors');
  });

  describe('refundPayment', () => {
    it('should refund valid transaction');
    it('should reject invalid transaction');
  });
});

Implementation-Coupled Tests (Refactor)

1.

test/api/user-service.test.ts:45

Issue: Tests private method

_validateEmail

Risk: Will break on internal refactoring Current:

it('should validate email', () => {
  expect(service._validateEmail('test@test.com')).toBe(true);
});

Suggested Fix:

it('should reject user with invalid email', () => {
  expect(() => service.createUser({ email: 'invalid' }))
    .toThrow('Invalid email');
});

Test-Code Mapping

Test File	Source File	Status
test/auth/login.test.ts	src/auth/login.ts	✅ Aligned
test/user/profile.test.ts	src/user/profile.ts	✅ Aligned
test/api/old-client.test.ts	(deleted)	❌ Orphaned
(missing)	src/payment/processor.ts	⚠️ Missing

Recommendations

1. Immediate: Delete 3 orphaned test files
2. This Sprint: Create tests for

   processor.ts

   (critical)
3. Debt Reduction: Refactor 5 implementation-coupled tests
4. Ongoing: Add test-sync to CI pipeline

CI Integration

Add to pre-commit or CI:

- name: Test Sync Check
  run: |
    npx test-sync --project . --strict
    # Fails if orphaned tests or missing critical tests

## Cleanup Actions

### Safe Deletions (Automated)

```bash
# Delete orphaned test files
rm test/auth/legacy-login.test.ts
rm test/utils/old-helpers.test.ts

# Remove orphaned test blocks
sed -i '/describe.*formatCurrency/,/^});$/d' test/utils/string.test.ts

Manual Review Required

• Tests for code moved to different module
• Tests that may cover shared utilities
• Tests with unclear naming

Integration Points

• Works with

  /check-traceability

  command
• Reports to Test Architect
• Feeds into test health metrics
• Part of

  /project-health-check

Script Reference

test_sync.py

Run sync analysis:

python scripts/test_sync.py --project . --output report.md

cleanup_orphans.py

Remove orphaned tests:

python scripts/cleanup_orphans.py --project . --dry-run

References

• @$AIWG_ROOT/agentic/code/addons/testing-quality/README.md — Testing quality addon overview
• @$AIWG_ROOT/agentic/code/frameworks/sdlc-complete/README.md — SDLC framework context for test traceability
• @$AIWG_ROOT/agentic/code/addons/aiwg-utils/rules/human-authorization.md — Authorization before deleting test files
• @$AIWG_ROOT/docs/cli-reference.md — CLI reference for check-traceability command