regression-test-development

What problem does it solve? When a bug is fixed or a new behavior is requested, teams often lack durable automated tests that would catch the same defect if it returned. This Skill converts a confirmed defect or behavior requirement into focused, maintainable regression coverage with documented execution evidence. ## Core Features & Use Cases - Red-Green Test Development: Writes the smallest test that fails for the missing behavior, applies the minimal production fix, and captures both failing and passing evidence. - Bounded Write Scope: Modifies only tests, fixtures, and minimal production code required by the requested behavior, never weakening unrelated assertions. - Structured Reporting: Produces reports/regression-test-result.json and reports/regression-test-result.md recording changed files, validation commands, and residual gaps. - Use Case: After systematic-debugging identifies a parser defect, use this Skill to add a reproducing test, demonstrate the failure, repair the parser, and verify neighboring tests still pass. ## Quick Start Ask the agent to add a regression test that reproduces the reported defect, fix the underlying behavior, and capture red-green validation evidence.