Type Alias RequireAtLeastOne<ObjectType, KeysType>

RequireAtLeastOne: {
    [Key in KeysType]-?: Required<Pick<ObjectType, Key>> & Partial<
        Pick<ObjectType, Exclude<KeysType, Key>>,
    >
}[KeysType] & Except<ObjectType, KeysType>

Create a type that requires at least one of the given keys. The remaining keys are kept as is.

Type Parameters

ObjectType
KeysType extends keyof ObjectType = keyof ObjectType

Example

import type {RequireAtLeastOne} from 'type-fest';

type Responder = {
	text?: () => string;
	json?: () => string;
	secure?: boolean;
};

const responder: RequireAtLeastOne<Responder, 'text' | 'json'> = {
	json: () => '{"message": "ok"}',
	secure: true
};