Type Alias DiscriminatedUnion<Tag, Map>

DiscriminatedUnion: { [K in keyof Map & string]: { [P in Tag]: K } & Map[K] }[keyof Map & string]

Build a discriminated union from a tag key and mapping

Type Parameters

Tag extends string
Map extends Record<string, any>

Example

type Map = { cat: { meows: boolean }; dog: { barks: boolean } };
type DU = DiscriminatedUnion<'type', Map>;
// { type: 'cat'; meows: boolean } | { type: 'dog'; barks: boolean }