source: node_modules/type-fest/source/set-required.d.ts

import {Except} from './except';

/**
Create a type that makes the given keys required. The remaining keys are kept as is. The sister of the `SetOptional` 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 required.

@example
```
import {SetRequired} from 'type-fest';

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

type SomeRequired = SetRequired<Foo, 'b' | 'c'>;
// type SomeRequired = {
//      a?: number;
//      b: string; // Was already required and still is.
//      c: boolean; // Is now required.
// }
```
*/
export type SetRequired<BaseType, Keys extends keyof BaseType = keyof BaseType> =
        // Pick just the keys that are not required from the base type.
        Except<BaseType, Keys> &
        // Pick the keys that should be required from the base type and make them required.
        Required<Pick<BaseType, Keys>> extends
        // If `InferredType` extends the previous, then for each key, use the inferred type key.
        infer InferredType
                ? {[KeyType in keyof InferredType]: InferredType[KeyType]}
                : never;