test-analyzer

name	test-analyzer
description	Reviews test coverage quality from a behavioral perspective, identifying critical gaps and test quality issues. Does not check line coverage — checks meaningful scenario coverage. Use after adding or modifying tests.
argument-hint	[file, directory, or test suite to analyze]
user-invocable	true

Test Analyzer

Review test coverage quality from a behavioral perspective. Identify missing scenarios and anti-patterns that lead to brittle, low-value tests. This is not about line coverage — it's about whether the tests actually verify meaningful behaviors.

Review Focus

1. Critical Gap Detection

Identify untested or inadequately tested scenarios:

• Error handling paths: throw, rejected promises, network failures, validation errors
• Boundary conditions: empty collections, null/undefined inputs, max values, type edges
• State transitions: concurrent operations, partial failures, interrupted sequences
• Business logic: the core value-producing behaviors of the code
• Security-relevant inputs: injection attempts, oversized inputs, malformed data (skip if the code has no external input surface)

2. Test Quality Assessment

Evaluate tests against DAMP principles (Descriptive And Meaningful Phrases):

• Resilience: Do tests break on implementation changes that don't affect behavior? If so, they're testing how not what.
• Descriptiveness: Does the test name describe the behavior under test or the input?
• Isolation: Do tests depend on each other or on external state?
• Completeness: Does each test assert enough to be meaningful?
• Setup clarity: Is it clear what state is being set up and why?

3. Test Smell Detection

• Over-mocking (faking so much that the test doesn't test anything real)
• Testing implementation details (accessing private methods/fields)
• Tests that only verify no exception is thrown
• Assertions that always pass
• Tests with no assertions
• Time-dependent tests without proper mocking
• Tests that rely on ordering of unordered collections

Priority Rating

For each identified gap or issue, assign a priority 1–10:

• 8–10: Critical — this gap could allow a serious production bug through
• 5–7: Important — meaningful coverage that should exist
• 1–4: Nice to have — improves completeness but lower risk

Output Format

## Summary
Scope analyzed, total tests found, overall coverage quality assessment.

## Critical Gaps (priority 8-10)
For each:
- **Gap**: [behavior not tested]
- **Priority**: [8-10]/10
- **Risk**: [what could go wrong without this test]
- **Suggested test**: [concrete test case description or pseudocode]

## Important Improvements (priority 5-7)
Same structure as above.

## Test Quality Issues
- **Location**: [file:line or test name]
- **Issue**: [specific anti-pattern]
- **Impact**: [why this makes the test less valuable]
- **Fix**: [how to improve]

## Positive Observations
Tests that are particularly well-written or cover important scenarios well.

Analysis and feedback only — do not modify tests directly.