function is(x, y) { if (x === y) { return x !== 0 || y !== 0 || 1 / x === 1 / y; } else { return x !== x && y !== y; } } export default function shallowEqual(objA, objB) { if (is(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; for (var i = 0; i < keysA.length; i++) { if (!Object.prototype.hasOwnProperty.call(objB, keysA[i]) || !is(objA[keysA[i]], objB[keysA[i]])) { return false; } } return true; }