Type Alias UnionMerge<U>

UnionMerge: {
    [K in UnionKeys<U>]?: U extends any
        ? K extends keyof U ? U[K] : never
        : never
}

Merge a union of object types into a single object type.

Type Parameters

U
Union of object types

Remarks

All properties from all union members are combined. Properties not present in every member become optional.

This is a structural merge and may lose discriminant information.

Example

type U = { a: string } | { b: number };
type M = UnionMerge< U >;
// { a?: string; b?: number }