What problem does it solve? When an AI coding assistant writes code and then reviews its own work, it carries the same assumptions into both steps, creating systematic blind spots where bugs survive review. This Skill provides testing patterns that mechanically catch these AI-introduced regressions, especially sandbox/production path mismatches and incomplete SELECT clauses. ## Core Features & Use Cases - Sandbox-Mode API Testing: Set up Vitest with Next.js App Router to test API routes without a database by forcing sandbox/mock mode via environment variables. - Bug-Driven Regression Tests: Write tests targeting bugs that were actually found, asserting API response shapes and required fields rather than implementation details. - Bug-Check Workflow Integration: Embed automated test and build runs as mandatory first steps in code review commands before any AI self-review. - Use Case: After an AI assistant fixes a missing notification_settings field in a profile API, write a regression test asserting the field exists in the response, then run it in every bug-check so the same bug cannot be reintroduced. ## Quick Start Ask the AI to set up sandbox-mode Vitest regression tests for the API route where a bug was just fixed, asserting all required response fields are present.
