Proposal: SetFieldType

[lucasteles]

A simple shallow field type replace utility type

definition:

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

export type SetFieldType<BaseType, Keys extends keyof BaseType, NewType> =
  Simplify<
  Except<BaseType, Keys> &
  Record<Keys, NewType>
  >;

use case:

type MyModel = { id: number; createdAt: Date; updatedAt: Date; enabled: boolean }
type MyModelApi = SetFieldType<MyModel, 'createdAt' | 'updatedAt', string>
// MyModelApi == { id: number; createdAt: string; updatedAt: string; enabled: boolean }

const response = fetch<MyModelApi>("url")

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[sindresorhus]

I would name it SetFieldType.

[sindresorhus]

Related type: #675

[lucasteles]

@sindresorhus looks great, i will update the issue

[Emiyaaaaa]

This type seem like type Overwrite<T, K> = Omit<T, keyof K> & K
Maybe Overwrite<MyModel, {createdAt: string, updatedAt: string}> is more universal?

@sindresorhus Thoughts?

[sindresorhus]

Maybe Overwrite<MyModel, {createdAt: string, updatedAt: string}> is more universal?

Yeah, I like it better. More flexible as you can replace multiple properties with different types at once.

[Emiyaaaaa]

Yeah, I like it better. More flexible as you can replace multiple properties with different types at once.

I found Merge is same to Overwrite in this case. can just use Merge before having the case that Overwrite is better than Merge

[lucasteles]

I believe overwrite/merge is not quite what I am aiming for here

I have used this approach before and I figured myself having to repeat the structure and the same type multiple times which made me create this helper, to easily change multiple fields to one single type

[sindresorhus]

Thinking more about this, I think we can have both types.