Type Alias RequireAtLeastOne<T, K>

RequireAtLeastOne: Pick<T, Exclude<keyof T, K>> & {
[P in K]: Required<Pick<T, P>> & Partial<Pick<T, Exclude<K, P>>>
}[K]

Require at least one property from a set of properties

type Test = { a?: string; b?: number; c: boolean };
type Result = RequireAtLeastOne<Test, 'a' | 'b'>;