immutableUtils.ts

/**
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 */

// SENTINEL constants are from https://github.com/immutable-js/immutable-js/tree/main/src/predicates
const IS_KEYED_SENTINEL = '@@__IMMUTABLE_KEYED__@@';
const IS_SET_SENTINEL = '@@__IMMUTABLE_SET__@@';
const IS_LIST_SENTINEL = '@@__IMMUTABLE_LIST__@@';
const IS_ORDERED_SENTINEL = '@@__IMMUTABLE_ORDERED__@@';
const IS_RECORD_SYMBOL = '@@__IMMUTABLE_RECORD__@@';

function isObjectLiteral(source: unknown): source is Record<string, unknown> {
  return source != null && typeof source === 'object' && !Array.isArray(source);
}

export function isImmutableUnorderedKeyed(source: unknown): boolean {
  return Boolean(
    source &&
      isObjectLiteral(source) &&
      source[IS_KEYED_SENTINEL] &&
      !source[IS_ORDERED_SENTINEL],
  );
}

export function isImmutableUnorderedSet(source: unknown): boolean {
  return Boolean(
    source &&
      isObjectLiteral(source) &&
      source[IS_SET_SENTINEL] &&
      !source[IS_ORDERED_SENTINEL],
  );
}

export function isImmutableList(source: unknown): boolean {
  return Boolean(source && isObjectLiteral(source) && source[IS_LIST_SENTINEL]);
}

export function isImmutableOrderedKeyed(source: unknown): boolean {
  return Boolean(
    source &&
      isObjectLiteral(source) &&
      source[IS_KEYED_SENTINEL] &&
      source[IS_ORDERED_SENTINEL],
  );
}

export function isImmutableOrderedSet(source: unknown): boolean {
  return Boolean(
    source &&
      isObjectLiteral(source) &&
      source[IS_SET_SENTINEL] &&
      source[IS_ORDERED_SENTINEL],
  );
}

export function isImmutableRecord(source: unknown): boolean {
  return Boolean(source && isObjectLiteral(source) && source[IS_RECORD_SYMBOL]);
}