Type Alias SetOptional<BaseType, Keys>

SetOptional: (
    BaseType extends (...arguments_: never) => any
        ? (...arguments_: Parameters<BaseType>) => ReturnType<BaseType>
        : unknown
) & _SetOptional<BaseType, Keys>

Create a type that makes the given keys optional. The remaining keys are kept as is. The sister of the SetRequired type.

Use-case: You want to define a single model where the only thing that changes is whether or not some of the keys are optional.

Type Parameters

BaseType
Keys extends keyof BaseType

Example

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

type Foo = {
	a: number;
	b?: string;
	c: boolean;
};

type SomeOptional = SetOptional<Foo, 'b' | 'c'>;
// type SomeOptional = {
// 	a: number;
// 	b?: string; // Was already optional and still is.
// 	c?: boolean; // Is now optional.
// }