githubmirror/immutable-js

src/predicates/isCollection.ts

27 строк909 B

Julien Deniau

import comments into TS files

23 фев 2025, 22:59

23 фев 2025, 22:59c16cbcf

import type { Collection } from '../../type-definitions/immutable';

// Note: value is unchanged to not break immutable-devtools.
export const IS_COLLECTION_SYMBOL = '@@__IMMUTABLE_ITERABLE__@@';

/**
 * True if `maybeCollection` is a Collection, or any of its subclasses.
 *
 * ```js
 * import { isCollection, Map, List, Stack } from 'immutable';
 *
 * isCollection([]); // false
 * isCollection({}); // false
 * isCollection(Map()); // true
 * isCollection(List()); // true
 * isCollection(Stack()); // true
 * ```
 */
export function isCollection(
  maybeCollection: unknown
): maybeCollection is Collection<unknown, unknown> {
  return Boolean(
    maybeCollection &&
      // @ts-expect-error: maybeCollection is typed as `{}`, need to change in 6.0 to `maybeCollection && typeof maybeCollection === 'object' && IS_COLLECTION_SYMBOL in maybeCollection`
      maybeCollection[IS_COLLECTION_SYMBOL]
  );
}