source: trip-planner-front/node_modules/type-fest/source/set-optional.d.ts@ 84d0fbb

import {Except} from './except';
import {Simplify} from './simplify';

/**
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.

@example
```
import {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.
// }
```
*/
export type SetOptional<BaseType, Keys extends keyof BaseType> =
        Simplify<
                // Pick just the keys that are readonly from the base type.
                Except<BaseType, Keys> &
                // Pick the keys that should be mutable from the base type and make them mutable.
                Partial<Pick<BaseType, Keys>>
        >;