typescript-exhaustive-switch

What problem does it solve?

This Skill prevents silent logic gaps in TypeScript by forcing switch statements over discriminated unions or enums to handle every possible variant, so newly added variants fail fast at compile time instead of causing runtime bugs.

Core Features & Use Cases

• Exhaustive default never check: Uses the default branch to create a compile-time error when an unhandled variant appears.
• Works for discriminated unions and enums: Ensures safety when switching over kind-style tagged unions, string literal unions, or enums.
• Clear failure signal: Produces a type-checking failure that points developers directly to the missing case.

Quick Start

When you are editing a TypeScript switch over a discriminated union, apply an exhaustive default branch using a never-typed variable so TypeScript reports a compile error if any variant is missing.