shallow-equals.js

// original sourc
// https://github.com/rackt/react-redux/blob/master/src/utils/shallowEqual.js
// MIT license
export default function shallowEqual(objA, objB) {
  if (objA === objB) {
    return true;
  }

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

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

  if (keysA.length !== keysB.length) {
    return false;
  }

  // Test for A's keys different from B.
  var bHasOwnProperty = Object.prototype.hasOwnProperty.bind(objB);
  for (var i = 0; i < keysA.length; i++) {
    if (
      !bHasOwnProperty(keysA[i]) ||
      objA[keysA[i]] !== objB[keysA[i]]
    ) {
      return false;
    }
  }

  return true;
}