| import {ArrayEntry, MapEntry, ObjectEntry, SetEntry} from './entry'; |
| |
| type ArrayEntries<BaseType extends readonly unknown[]> = Array<ArrayEntry<BaseType>>; |
| type MapEntries<BaseType> = Array<MapEntry<BaseType>>; |
| type ObjectEntries<BaseType> = Array<ObjectEntry<BaseType>>; |
| type SetEntries<BaseType extends Set<unknown>> = Array<SetEntry<BaseType>>; |
| |
| /** |
| Many collections have an `entries` method which returns an array of a given object's own enumerable string-keyed property [key, value] pairs. The `Entries` type will return the type of that collection's entries. |
| |
| For example the {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/entries|`Object`}, {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map/entries|`Map`}, {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/entries|`Array`}, and {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Set/entries|`Set`} collections all have this method. Note that `WeakMap` and `WeakSet` do not have this method since their entries are not enumerable. |
| |
| @see `Entry` if you want to just access the type of a single entry. |
| |
| @example |
| ``` |
| import {Entries} from 'type-fest'; |
| |
| interface Example { |
| someKey: number; |
| } |
| |
| const manipulatesEntries = (examples: Entries<Example>) => examples.map(example => [ |
| // Does some arbitrary processing on the key (with type information available) |
| example[0].toUpperCase(), |
| |
| // Does some arbitrary processing on the value (with type information available) |
| example[1].toFixed() |
| ]); |
| |
| const example: Example = {someKey: 1}; |
| const entries = Object.entries(example) as Entries<Example>; |
| const output = manipulatesEntries(entries); |
| |
| // Objects |
| const objectExample = {a: 1}; |
| const objectEntries: Entries<typeof objectExample> = [['a', 1]]; |
| |
| // Arrays |
| const arrayExample = ['a', 1]; |
| const arrayEntries: Entries<typeof arrayExample> = [[0, 'a'], [1, 1]]; |
| |
| // Maps |
| const mapExample = new Map([['a', 1]]); |
| const mapEntries: Entries<typeof map> = [['a', 1]]; |
| |
| // Sets |
| const setExample = new Set(['a', 1]); |
| const setEntries: Entries<typeof setExample> = [['a', 'a'], [1, 1]]; |
| ``` |
| */ |
| export type Entries<BaseType> = |
| BaseType extends Map<unknown, unknown> ? MapEntries<BaseType> |
| : BaseType extends Set<unknown> ? SetEntries<BaseType> |
| : BaseType extends unknown[] ? ArrayEntries<BaseType> |
| : BaseType extends object ? ObjectEntries<BaseType> |
| : never; |