froebel/nullish.d.ts

TypeScript utility library

/** Checks if `value` is nullish. Literal types are narrowed accordingly. */
export declare const nullish: <T>(value: T) => value is Nullish<T>;
declare type Nullish<T> = PickNullish<T> extends never ? Extract<T, undefined | null> : PickNullish<T>;
declare type PickNullish<T> = (null extends T ? null : never) | (undefined extends T ? undefined : never);
/**
 * Checks if `value` is not nullish. Literal types are narrowed accordingly.
 *
 * @example
 * ```
 * const nums = (...values: (number | undefined)[]): number[] => values.filter(notNullish)
 * ```
 */
export declare const notNullish: <T>(value: T | null | undefined) => value is T;
export {};