test-your-types

What problem does it solve?

Type-level code can have bugs too, and type declarations can drift out of sync with implementations. Testing types ensures correctness, catches drift, and improves maintainability across libraries and complex utilities.

Core Features & Use Cases

• Write type tests for libraries, complex type utilities, and when types and implementations are in separate files.
• Validate that valid types compile and invalid types error with helpful messages.
• Use examples and patterns across TypeScript projects to verify type behavior during refactoring or library evolution.

Quick Start

Create and run a small type-level test to verify that a nested type becomes deeply readonly.