Add SetRequiredDeep type

[hugomartinet]

Closes #796

This pull request adds a new SetRequiredDeep which, like SetRequired, allows to make one or several keys in a model required. It adds the possibility to select nested keys by specifying their path.

Example

type AnOptionalType = {
  foo?: {
    bar?: number
    baz?: string
  }
}


type ARequiredDeepType = SetRequiredDeep< AnOptionalType, 'foo.bar'>;
// type ARequiredDeepType = {
//   foo: {
//     bar: number
//     baz?: string
//   }
// }

[Emiyaaaaa]

Can this feature be added on SetRequired instead of a new type? just move code into SetRequired

@sindresorhus how about you think?

[sindresorhus]

The problem with doing both shallow and deep in a single method is that the deep logic affects the performance even if you don't need deep. This was the case for Simplify, where we had to split it out into a SimplifyDeep version.

[Emiyaaaaa]

Suggested change

	type SomeRequiredDeep = SetRequiredDeep<Foo, 'a' | 'array.c'>;
	type SomeRequiredDeep = SetRequiredDeep<Foo, 'a' | 'array.${number}.c'>;

I kinda forgot how it's should be. You can add the example in test to ensure it is worked.

[Emiyaaaaa]

I kinda forgot how it's should be. You can add the example in test to ensure it is worked.

This doesn't seem to be resolved @hugomartinet

[Emiyaaaaa]

Need to resolve all conversation

[hugomartinet]

Need to resolve all conversation

Done

[Beraliv]

Is it worth adding a test case with multiple paths (i.e. BaseType is not a union)?

declare const variation2: SetRequiredDeep<{a?: number; b?: {c?: string}}, 'a' | 'b'>;
expectType<{a: number; b: {c?: string}}>(variation2);

[Beraliv]

I'm playing with this solution using the following example:

type Teacher = { address?: { postcode?: string; city?: string } };
type P1 = SetRequiredDeep<Teacher, 'address' | 'address.city'>;
//      ^?

This gives me:

type P1 = {
    address: {
        postcode: string;
        city: string;
    };
} | {
    address: {
        postcode: string;
        city: string;
    };
}

Is the result expected?

To elaborate:

1. Why is the postcode required?
2. Why is the result object a union? Are there any plans to merge a union into a single object?

[Emiyaaaaa]

I agree, similar to PickDeep and OmitDeep. result should be

type P1 = { 
  address: { 
    postcode?: string; 
    city: string; 
  }; 
}

[hugomartinet]

Yes I think my current implementation could not work for this, since I use RequiredDeep and RequiredDeep makes all child keys of an object required as well.