Typescript Union Keys And Make Uncommon Keys Optional

type A = {name: string} type B = {name: number} type C = {name: string , age:number} type D = {name: string , age:string} type E = {name: string , address:string} type Prettify<T extends Record<string, unknown>> = { [K in keyof T]: T[K] } type UnionKeysAndMakeUncommonKeysOptional< T extends Record<string, unknown>[], ACC extends Record<string, unknown>={}, UncommonKeyACC extends string = never > = T extends [] ? Prettify<Omit<ACC, UncommonKeyACC> & Partial<Pick<ACC, UncommonKeyACC>>> : T extends [infer R, ...infer S extends Record<string, unknown>[]] ? UnionKeysAndMakeUncommonKeysOptional< S, { [K in keyof R | keyof ACC]: R[K & keyof R] | ACC[K & keyof ACC] }, Exclude<keyof ACC | keyof R, keyof ACC & keyof R> & string > : never type result = UnionKeysAndMakeUncommonKeysOptional<[A,B,C,D,E]> // { // name: string | number; // age?: string | number; // address?: string; // }