zod-contract-testing

Schemas define contracts between systems. A schema that accepts invalid data is a security hole. A schema that rejects valid data is a broken integration. This skill teaches you to systematically test schemas at system boundaries.

When to use: Testing API request/response schemas, WebSocket message validation, database record parsing, external data ingestion, any Zod schema at a system boundary.

When not to use: Internal type assertions, UI component props, type definitions without runtime validation.

Validates Zod schema parsing at boundaries.测试有效/无效输入、模式演变、细化覆盖率和复合状态矩阵（2^N 可选字段组合）。 来源：apankov1/quality-engineering。