What problem does it solve? Go packages often ship with uncovered functions, untested error paths, and assertions that would pass even when the code is wrong. This Skill drives test coverage to 100% per touched package using a structured Research → Plan → Implement pipeline, then proves the tests actually catch bugs with condition coverage and mutation testing. ## Core Features & Use Cases - Coverage Gap Analysis: Measures baseline coverage with go test -coverprofile, ranks uncovered and partially covered functions by priority, and maps existing test helpers like testutil.NewTestClient() and testutil.RespondJSON(). - Table-Driven Test Generation: Writes buildable tests using httptest mocks for GitLab API endpoints, covering happy paths, error responses, pagination, context cancellation, and edge cases, with stdlib t.Errorf/t.Fatalf assertions only. - Mutation and Condition Verification: Gates each package on make coverage-mutants (Lived 0, Not covered 0 via gremlins) and make coverage-conditions (gobco), so decisions are exercised both ways and no mutant survives. - Use Case: After adding a new tool handler to a Go MCP server, run this Skill to generate the missing tests, mock the GitLab API responses, and verify the package reaches 100% coverage with zero lived mutants before opening the pull request. ## Quick Start Ask the agent to increase test coverage for the package you just changed, for example: raise internal/tools to 100% coverage and verify it with mutation and condition checks.
