paths.ts
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| /** | |
| * Example usage: | |
| * | |
| * // default depth of 3: (fastest) | |
| * type keys = Paths<SomeNestedObject> // returns "property" | "nested.property" | "nested.nested.property" | |
| * | |
| * // depth of 10: (can be slow) | |
| * type keys = Paths<SomeNestedObject, 10> | |
| * | |
| * // depth of 10 with keys of type string and number: (slowest) | |
| * type keys = Paths<SomeNestedObject, 10, string | number> | |
| */ | |
| type Join< | |
| Key, | |
| Previous, | |
| TKey extends number | string = string | |
| > = Key extends TKey | |
| ? Previous extends TKey | |
| ? `${Key}${'' extends Previous ? '' : '.'}${Previous}` | |
| : never | |
| : never; | |
| type Previous = [never, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ...0[]]; | |
| export type Paths< | |
| TEntity, | |
| TDepth extends number = 3, | |
| TKey extends number | string = string | |
| > = [TDepth] extends [never] | |
| ? never | |
| : TEntity extends object | |
| ? { | |
| [Key in keyof TEntity]-?: Key extends TKey | |
| ? `${Key}` | Join<Key, Paths<TEntity[Key], Previous[TDepth]>> | |
| : never; | |
| }[keyof TEntity] | |
| : ''; |
