-
-
Notifications
You must be signed in to change notification settings - Fork 576
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
6 changed files
with
425 additions
and
37 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,195 @@ | ||
| import type {NonRecursiveType, MinNumbers, MaxNumbers, TupleLength, FixedPartOfArray, NonFixedPartOfArray} from './internal'; | ||
| import type {IsNever} from './is-never'; | ||
| import type {UnknownArray} from './unknown-array'; | ||
|
|
||
| /** | ||
| Set the given array to readonly if `IsReadonly` is `true`, otherwise set the given array to normal, then return the result. | ||
| @example | ||
| ``` | ||
| type ReadonlyArray = readonly string[]; | ||
| type NormalArray = string[]; | ||
| type ReadonlyResult = SetArrayAccess<NormalArray, true>; | ||
| //=> readonly string[] | ||
| type NormalResult = SetArrayAccess<ReadonlyArray, false>; | ||
| //=> string[] | ||
| ``` | ||
| */ | ||
| type SetArrayAccess<T extends UnknownArray, IsReadonly extends boolean> = | ||
| T extends readonly [...infer U] ? | ||
| IsReadonly extends true | ||
| ? readonly [...U] | ||
| : [...U] | ||
| : T; | ||
|
|
||
| /** | ||
| Returns whether the given array `T` is readonly. | ||
| */ | ||
| type ArrayIsReadonly<T extends UnknownArray> = T extends unknown[] ? false : true; | ||
|
|
||
| /** | ||
| SharedUnionFieldsDeep options. | ||
| @see {@link SharedUnionFieldsDeep} | ||
| */ | ||
| export type SharedUnionFieldsDeepOptions = { | ||
| /** | ||
| Whether to affect the individual elements of arrays and tuples. | ||
| If this option is set to `true` and all of the value in union are arrays or tuples, | ||
| we will build a minimum possible length array that each element in the array is exist in the union array. | ||
| @default false | ||
| */ | ||
| recurseIntoArrays?: boolean; | ||
| }; | ||
|
|
||
| /** | ||
| Create a deep version of anther object that has the shared fields of the given union object type. | ||
| uses the {@link SharedUnionFieldsDeepOptions `Options`} to specify the behavior of the array. | ||
| Use-cases: | ||
| - You want a safe object type that each key is exist in the union object. | ||
| - You want focus on the common fields of the union type and don't want to care about the other fields. | ||
| @example | ||
| ``` | ||
| import type {SharedUnionFieldsDeep} from 'type-fest'; | ||
| type Cat = { | ||
| info: { | ||
| name: string; | ||
| type: 'cat'; | ||
| catType: string; | ||
| }; | ||
| }; | ||
| type Dog = { | ||
| info: { | ||
| name: string; | ||
| type: 'dog'; | ||
| dogType: string; | ||
| }; | ||
| }; | ||
| function displayPetInfo(petInfo: (Cat | Dog)['info']) { | ||
| // typeof petInfo => | ||
| // { | ||
| // name: string; | ||
| // type: 'cat'; | ||
| // catType: string; // Needn't care about this field, because it's not a common pet info field. | ||
| // } | { | ||
| // name: string; | ||
| // type: 'dog'; | ||
| // dogType: string; // Needn't care about this field, because it's not a common pet info field. | ||
| // } | ||
| // petInfo type is complex and have some needless fields | ||
| console.log('name: ', petInfo.name); | ||
| console.log('type: ', petInfo.type); | ||
| } | ||
| function displayPetInfo(petInfo: SharedUnionFieldsDeep<Cat | Dog>['info']) { | ||
| // typeof petInfo => | ||
| // { | ||
| // name: string; | ||
| // type: 'cat' | 'dog'; | ||
| // } | ||
| // petInfo type is simple and clear | ||
| console.log('name: ', petInfo.name); | ||
| console.log('type: ', petInfo.type); | ||
| } | ||
| ``` | ||
| @category Object | ||
| @category Union | ||
| */ | ||
| export type SharedUnionFieldsDeep<Union, Options extends SharedUnionFieldsDeepOptions = {recurseIntoArrays: false}> = | ||
| // `Union extends` will convert `Union` | ||
| // to a [distributive conditionaltype](https://www.typescriptlang.org/docs/handbook/release-notes/typescript-2-8.html#distributive-conditional-types). | ||
| // But this is not what we want, so we need to wrap `Union` with `[]` to prevent it. | ||
| [Union] extends [NonRecursiveType | ReadonlyMap<unknown, unknown> | ReadonlySet<unknown>] | ||
| ? Union | ||
| : [Union] extends [UnknownArray] | ||
| ? Options['recurseIntoArrays'] extends true | ||
| ? SetArrayAccess<SharedArrayUnionFieldsDeep<Union, Options>, ArrayIsReadonly<Union>> | ||
| : Union | ||
| : [Union] extends [object] | ||
| ? SharedObjectUnionFieldsDeep<Union, Options> | ||
| : Union; | ||
|
|
||
| /** | ||
| Same as `SharedUnionFieldsDeep`, but accepts only `object`s and as inputs. Internal helper for `SharedUnionFieldsDeep`. | ||
| */ | ||
| type SharedObjectUnionFieldsDeep<Union, Options extends SharedUnionFieldsDeepOptions> = | ||
| keyof Union extends infer Keys | ||
| ? IsNever<Keys> extends false | ||
| ? { | ||
| [Key in keyof Union]: | ||
| Union[Key] extends NonRecursiveType | ||
| ? Union[Key] | ||
| : SharedUnionFieldsDeep<Union[Key], Options> | ||
| } | ||
| : {} | ||
| : Union; | ||
|
|
||
| /** | ||
| Same as `SharedUnionFieldsDeep`, but accepts only `UnknownArray`s and as inputs. Internal helper for `SharedUnionFieldsDeep`. | ||
| */ | ||
| type SharedArrayUnionFieldsDeep<Union extends UnknownArray, Options extends SharedUnionFieldsDeepOptions> = | ||
| // Restore the readonly modifier of the array. | ||
| SetArrayAccess< | ||
| InternalSharedArrayUnionFieldsDeep<Union, Options>, | ||
| ArrayIsReadonly<Union> | ||
| >; | ||
|
|
||
| /** | ||
| Internal helper for `SharedArrayUnionFieldsDeep`. Needn't care the `readonly` modifier of arrays. | ||
| */ | ||
| type InternalSharedArrayUnionFieldsDeep< | ||
| Union extends UnknownArray, | ||
| Options extends SharedUnionFieldsDeepOptions, | ||
| ResultTuple extends UnknownArray = [], | ||
| > = | ||
| // We should build a minimum possible length tuple that each element in the tuple is exist in the union tuple. | ||
| IsNever<TupleLength<Union>> extends true | ||
| // Rule 1: If all the arrays in the union have non-fixed lengths, | ||
| // like `Array<string> | [number, ...string[]]` | ||
| // we should build a tuple that is [the_fixed_parts_of_union, ...the_rest_of_union[]]. | ||
| // For example: `InternalSharedArrayUnionFieldsDeep<Array<string> | [number, ...string[]]>` | ||
| // => `[string | number, ...string[]]`. | ||
| ? ResultTuple['length'] extends MaxNumbers<FixedPartOfArray<Union>['length']> | ||
| ? [ | ||
| // The fixed-length part of the tuple. | ||
| ...ResultTuple, | ||
| // The rest of the union. | ||
| // Due to `ResultTuple` is the maximum possible fixed-length part of the tuple, | ||
| // so we can use `FixedPartOfArray` to get the rest of the union. | ||
| ...Array< | ||
| SharedUnionFieldsDeep<NonFixedPartOfArray<Union>[number], Options> | ||
| >, | ||
| ] | ||
| // Build the fixed-length tuple recursively. | ||
| : InternalSharedArrayUnionFieldsDeep< | ||
| Union, Options, | ||
| [...ResultTuple, SharedUnionFieldsDeep<Union[ResultTuple['length']], Options>] | ||
| > | ||
| // Rule 2: If at least one of the arrays in the union have fixed lengths, | ||
| // like `Array<string> | [number, string]`, | ||
| // we should build a tuple of the smallest possible length to ensure any | ||
| // item in the result tuple is exist in the union tuple. | ||
| // For example: `InternalSharedArrayUnionFieldsDeep<Array<string> | [number, string]>` | ||
| // => `[string | number, string]`. | ||
| : ResultTuple['length'] extends MinNumbers<TupleLength<Union>> | ||
| ? ResultTuple | ||
| // As above, build tuple recursively. | ||
| : InternalSharedArrayUnionFieldsDeep< | ||
| Union, Options, | ||
| [...ResultTuple, SharedUnionFieldsDeep<Union[ResultTuple['length']], Options>] | ||
| >; |
Oops, something went wrong.