Let's say I have the following:
type UnionType = CustomType1 | CustomType2 | CustomType3;
// is there a way to accomplish this, without having to type it out like so.
type UnionTypeArr = CustomType1[] | CustomType2[] | CustomType3[];
CodePudding user response：
You can use a distributive conditional type (a conditional type of the form T extends X ? Y : Z where T is a generic type parameter) to split a union into its members, perform a transformation on each member, and combine the result into another union:
type DistribArrayify<T> = T extends unknown ? Array<T> : never;
type UnionType = CustomType1 | CustomType2 | CustomType3;
type UnionTypeArr = DistribArrayify<UnionType>;
// type UnionTypeArr = CustomType1[] | CustomType2[] | CustomType3[]