TypeScript

Purpose

Use the type system to make invalid states unrepresentable. This skill covers strict-mode TypeScript, the advanced type features worth reaching for, and the discipline of validating untrusted data exactly once — at the boundary.

When to Use

• Starting a TypeScript project or tightening tsconfig.json.
• Removing any and unchecked casts from an existing codebase.
• Modeling a domain with discriminated unions and exhaustive matching.
• Writing a typed API client or SDK.
• Debugging inference failures in generic code.

Capabilities