assertion-quality
Analyzes the variety and depth of assertions across test suites in any language. Use when the user asks to evaluate assertion quality, find shallow tests, identify assertion-free tests (no assertions or only trivial ones like Assert.IsNotNull / toBeTruthy()), flag self-referential or tautological assertions, measure assertion diversity, or audit whether tests verify different facets of behavior. Polyglot: .NET, Python, TS/JS, Java, Go, Ruby, Rust, Swift, Kotlin, PowerShell, C++. DO NOT USE FOR: writing new tests (use code-testing-agent / writing-mstest-tests), mutation reasoning about whether
npx skills add dotnet/skills --skill assertion-quality --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# 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**: Call the `test-analysis-extensions` skill to discover available extension files, then read the file matching the target codebase's language and framework (e.g., `dotnet.md` for .NET, `python.md` for pytest, `typescript.md` for Jest, `go.md` for the standard `testing` package). You MUST read the relevant extension file before classifying assertions, because assertion APIs differ significantly across frameworks. ## 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 obses
- Why Assertion Diversity Matters
- When to Use
- When Not to Use
- Inputs
- Workflow
- Step 1: Detect language and load extension
- Step 2: Gather the test code
- Step 3: Classify every assertion
- Step 4: Compute metrics
- Step 5: Apply calibration rules
- Step 6: Report findings
- Validation
- Common Pitfalls
What does the assertion-quality skill do?
Analyzes the variety and depth of assertions across test suites in any language. Use when the user asks to evaluate assertion quality, find shallow tests, identify assertion-free tests (no assertions or only trivial ones like Assert.IsNotNull / toBeTruthy()), flag self-referential or tautological assertions, measure assertion diversity, or audit whether tests verify different facets of behavior. Polyglot: .NET, Python, TS/JS, Java, Go, Ruby, Rust, Swift, Kotlin, PowerShell, C++. DO NOT USE FOR: writing new tests (use code-testing-agent / writing-mstest-tests), mutation reasoning about whether
How do I install it?
Run `npx skills add dotnet/skills --skill assertion-quality --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From dotnet/skills, a repository with 4,927 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.