Assertion Quality
Analyze assertion quality, depth, variety, and false confidence in existing tests.
Install
npx skills add managedcode/dotnet-skills --skill assertion-quality -g -a claude-code -y- Repository
- managedcode/dotnet-skills500
- Category
- Testing
- Updated
- 6d ago
- License
- MIT
- Context cost
- Mediumabout 3,000 tokens
- Runs scripts
- No, instructions only
What it does
Analyze assertion quality, depth, variety, and false confidence in existing tests. ALWAYS USE when asked about weak, shallow, trivial, always-true, self-referential, assertion-free, presence/truthiness-only, or insufficiently diverse assertions, including MSTest, Jest, pytest, and Go. DO NOT USE for direct fixes: writing-mstest-tests owns supplied MSTest assertions; code-testing owns new cases. Use test-gap-analysis when asked whether tests would catch a production change, and test-anti-patterns for general severity-ranked audits.
Assertion Diversity Analysis
Analyze test code in any supported language to measure how varied and meaningful the assertions are. Produce a metrics report that reveals whether tests verify different facets of correctness, not just "output equals X" but also structure, exceptions, state transitions, side effects, and invariants.
Language-specific guidance: Read the caller-provided or runtime-listed
test-analysis-extensionscatalog, then its matching language file (dotnet.md,python.md,typescript.md,go.md, etc.).test-analysis-extensionsis reference-only; do not invoke it as a skill. If the bundle is absent, use the pinned framework and this skill's rules, report the missing reference, and do not search installation directories.
Why Assertion Diversity Matters
Low assertion diversity signals shallow testing. Tests may pass while bugs hide in unasserted logic. Common symptoms:
| Problem | Symptom | Consequence |
|---|---|---|
| Trivial assertions | Test contains only Assert.IsNotNull(result) / assert result is not None / expect(x).toBeDefined() | Test passes but doesn't verify correctness |
| Single-value obsession | Always check one field or return value | Bugs in unasserted logic slip through |
| No negative assertions | Never check what shouldn't happen | Regressions sneak in through false positives |
| No state checks | Don't verify object state changes | Missed side-effects or lifecycle issues |
| No structural checks | Only assert top-level value | Bugs in nested objects go unnoticed |
| Assertion-free tests | Tests that call but don't verify | Code coverage lies; false security |
