Ai Rigor Coverage

AI Engineering Rigor — Test Coverage Analysis

Analyze $ARGUMENTS (default: HEAD~1) for test coverage gaps.

Phase 0: Load Config

Check for .ai-rigor/config.yml. If it exists, read:

• review.ignore — file patterns to skip
• Any test conventions from .ai-rigor/standards.md

Phase 1: Extract Changed Functions

1. Get the diff (same input detection as ai-rigor-review):

• File path: git diff HEAD --
• Commit range: git diff
• Default: git diff HEAD~1

1. For each changed Python file (skipping ignored patterns), extract:

• All def and async def signatures
• Skip __dunder__ methods and test_* functions

1. Map source files to expected test files:

• app/service.py -> search for tests/test_service.py or tests/test_app_service.py
• Use Glob: **/test_*{stem}*.py

Phase 2: Check Existing Coverage

For each changed function:

1. Grep for the function name in the mapped test file(s)
2. Mark as covered or uncovered
3. For covered functions, check if the test is meaningful

Phase 3: Suggest Missing Tests

For each uncovered function, suggest:

• Happy path — expected result for normal input
• Edge cases — empty, None, boundary values
• Error paths — invalid input behavior
• Integration — DB, API, or filesystem interactions

Output

## Test Coverage Analysis

**Config**: {.ai-rigor/config.yml | defaults}

### {source_file} -> {test_file}

| Function | Status | Notes |
|----------|--------|-------|
| `create_user(username, email)` | Uncovered | No test found |
| `get_user(user_id)` | Covered | test_get_user in test_service.py |

### Suggested Tests

**`create_user(username, email)`**
1. `test_create_user_returns_dict` — verify returns dict with expected fields
2. `test_create_user_empty_username` — verify behavior with empty string
3. `test_create_user_special_characters` — verify unicode handling

### Summary

| Metric | Value |
|--------|-------|
| Functions Changed | {N} |
| Covered | {N} |
| Uncovered | {N} |
| **Coverage Gap** | **{N}%** |

Rules

• Only analyze functions changed in the diff
• Skip test files, __init__.py, migrations, and files matching ignore patterns
• Suggest practical, implementable tests
• Trivial one-liners: note them, don't flag as critical

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: DivyaHemantCareer
• Source: DivyaHemantCareer/ai-engineering-rigor
• License: Apache-2.0

Install and usage instructions live in the source repository linked above.