29 lines
797 B
Plaintext
29 lines
797 B
Plaintext
/**
|
|
Matches any non-empty string.
|
|
|
|
This is useful when you need a string that is not empty, for example, as a function parameter.
|
|
|
|
NOTE:
|
|
- This returns `never` not just when instantiated with an empty string, but also when an empty string is a subtype of the instantiated type, like `string` or `Uppercase<string>`.
|
|
|
|
@example
|
|
```
|
|
import type {NonEmptyString} from 'type-fest';
|
|
|
|
declare function foo<T extends string>(string: NonEmptyString<T>): void;
|
|
|
|
foo('a');
|
|
//=> OK
|
|
|
|
foo('');
|
|
//=> Error: Argument of type '""' is not assignable to parameter of type 'never'.
|
|
|
|
declare const someString: string
|
|
foo(someString);
|
|
//=> Error: Argument of type 'string' is not assignable to parameter of type 'never'.
|
|
```
|
|
|
|
@category String
|
|
*/
|
|
export type NonEmptyString<T extends string> = '' extends T ? never : T;
|