Test gap analysis
Finds the behaviour that no test currently exercises and reports it as a list.
Installation
$ npx skills add dotnet/skillsThe CLI's unit is the repository, so this installs everything in dotnet/skills, not test-gap-analysis alone. It writes into whichever agent directories it finds — Claude Code, Codex, Cursor, Copilot, Windsurf, Zed.
Summary
Finds the behaviour that no test currently exercises and reports it as a list.
- Reach for it when inheriting a service with a suite nobody trusts and no idea where the holes are.
- Sits in Test — proving the change does what it claims — and finding the assertions that were never written.
- Assumes .net.
- Published by .NET team, who ship the thing it is about — a stronger claim than a well-regarded engineer having written something good.
- Installing pulls the whole dotnet/skills repository: this catalogue lists 4 other entries from it, and the repo may hold more.
Where it sits in delivery
TestProving the change does what it claims — and finding the assertions that were never written.Everything in Test →
The agent itself
The full text lives with its publisher and changes when they change it. Read it there rather than here — a mirrored copy of somebody else's procedure goes stale silently, and this page would have no way of telling you.
Related
More in Test
- Webapp testingDrives a real browser against a running app and reports what it found.
anthropics/skills - Browser testing with DevToolsUses the DevTools protocol to inspect, measure and reproduce behaviour in a live page.
addyosmani/agent-skills - Code testing agentA multi-agent pipeline that researches, plans and then generates a working test suite — language-agnostic despite the publisher.
dotnet/skills - PlaywrightAuthoring Playwright tests, shipped in the Playwright repository itself — locators, waiting, fixtures, traces.Skill
microsoft/playwright - Mutation testingBreaks the code on purpose to find out whether the suite notices — the only honest measure of test quality.Skill
trailofbits/skills - Property-based testingTests the invariant across generated inputs instead of the three examples you thought of.Skill
trailofbits/skills