react-esm/dist-src/shared/shallowEqual.js

React is a JavaScript library for building user interfaces.

/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * 
 */
import is from "./objectIs.js";
const hasOwnProperty = Object.prototype.hasOwnProperty;
/**
 * Performs equality by iterating through keys on an object and returning false
 * when any key has values which are not strictly equal between the arguments.
 * Returns true when the values of all keys are strictly equal.
 */

function shallowEqual(objA, objB) {
  if (is(objA, objB)) {
    return true;
  }

  if (typeof objA !== 'object' || objA === null || typeof objB !== 'object' || objB === null) {
    return false;
  }

  const keysA = Object.keys(objA);
  const keysB = Object.keys(objB);

  if (keysA.length !== keysB.length) {
    return false;
  } // Test for A's keys different from B.


  for (let i = 0; i < keysA.length; i++) {
    if (!hasOwnProperty.call(objB, keysA[i]) || !is(objA[keysA[i]], objB[keysA[i]])) {
      return false;
    }
  }

  return true;
}

export default shallowEqual;