check-tests

name	check-tests
description	Analyze test quality and coverage patterns
user_invocable	true
context	fork
agent	Explore

Test Quality Analysis

Assess test quality beyond simple coverage numbers — edge cases, patterns, and completeness.

Checks to Perform

1. Edge Case Coverage

Spot-check 3 test files for coverage of error and boundary conditions:

• Do tests include invalid/malformed inputs?
• Are nil, empty, and zero values tested?
• Are boundary conditions covered (max values, overflow)?

2. Table-Driven Test Usage

Check that multi-case functions use table-driven patterns:

• Search for test functions with more than 3 similar assertion blocks
• These are candidates for table-driven refactoring
• Report files that would benefit from the pattern

3. Round-Trip Tests

Verify decode-encode-decode cycles exist:

• Search for round-trip or roundtrip in test files
• Check that encoder tests verify output can be re-decoded
• Flag any encode/decode paths without round-trip verification

4. Error Message Quality

Spot-check 3 test files for error message assertions:

• Do tests check error message content (not just != nil)?
• Are error types checked with errors.Is() or errors.As()?
• Flag tests that only check err != nil without message validation

5. Critical Path Coverage

Cross-reference docs/testing.md critical paths with actual tests:

• For each critical function listed, verify a dedicated test exists
• Check that the test covers the "Required Tests" column
• Flag any critical paths without sufficient test coverage

6. Missing Test Files

Find .go files without corresponding _test.go files:

• List all non-test .go files (excluding doc.go, generated files)
• Check for corresponding _test.go
• Flag any missing test files (excluding trivially small files)

Output Format

## Test Quality Analysis

### Summary
| Dimension | Status | Findings |
|-----------|--------|----------|
| Edge cases | ... | ... |
| Table-driven | ... | ... |
| Round-trip tests | ... | ... |
| Error messages | ... | ... |
| Critical paths | ... | ... |
| Missing test files | ... | ... |

### Details
[Findings per dimension with file references]

### Recommendations
[Top items to improve test quality]