What problem does it solve? When behavior depends on history (order statuses, auth sessions, persisted entities), ad-hoc testing misses invalid transitions and cross-operation inconsistencies. This Skill mechanically derives test cases from state transition models and CRUD lifecycles using only the input/output specification, so defects hiding in forbidden sequences and post-delete references get covered. ## Core Features & Use Cases - State Transition Testing: Build a state x event table, enumerate all valid transitions and invalid events, and scale from 0-switch coverage to N-switch chains only where needed. - Forbidden/Permitted Sequence Derivation: Turn prohibition specs into reject tests and boundary-normal sequences into accept tests, almost one-to-one. - CRUD / Entity Lifecycle Testing: Fill an entity x {C,R,U,D} matrix with a C->R->U->R->D->R scenario, explicitly verifying post-delete reads, idempotent updates, and duplicate creation. - Use Case: Testing an order state machine in TypeScript/Vitest — enumerate valid transitions (created -> paid -> shipped -> delivered), assert invalid ones throw, and verify a repository returns null after delete. ## Quick Start Ask the AI to apply the blackbox-state techniques to derive state transition and CRUD lifecycle test cases for your order or repository module.
