exact

Exact<Type, Shape> returns Type when type Type and Shape are identical. Otherwise returns never

interface Dog {
  name: string;
  bark: () => void;
}

interface Cat {
  name: string;
  meow: () => void;
}

type CatEqualsToDog = Exact<Cat, Dog>;
//   ^? never

type DogEqualsToDog = Exact<Dog, Dog>;
//   ^? Dog

It supports:

• Arrays
• Object types
• Tuples
• Union types with objects
• Union types with primitives

It doesn't support:

• Enums

Support is addressed in #342

TS Playground – https://tsplay.dev/Wo8dlw