reactive-state
Version:
Redux-like state management using RxJS and TypeScript
58 lines • 2.01 kB
JavaScript
;
// shallowEqual taken from Facebooks fbjs util and converted to typescript from flow
// since this is used in react 16.x we trust FB that it works and disable code coverage here
Object.defineProperty(exports, "__esModule", { value: true });
exports.shallowEqual = void 0;
/**
* Copyright (c) 2013-present, Facebook, Inc.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
var hasOwnProperty = Object.prototype.hasOwnProperty;
/**
* inlined Object.is polyfill to avoid requiring consumers ship their own
* https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
*/
/* istanbul ignore next */
function is(x, y) {
// SameValue algorithm
if (x === y) {
// Steps 1-5, 7-10
// Steps 6.b-6.e: +0 != -0
// Added the nonzero y check to make Flow happy, but it is redundant
return x !== 0 || y !== 0 || 1 / x === 1 / y;
}
else {
// Step 6.a: NaN == NaN
return x !== x && y !== y;
}
}
/**
* 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.
*/
/* istanbul ignore next */
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;
}
// Test for A's keys different from B.
for (var i = 0; i < keysA.length; i++) {
if (!hasOwnProperty.call(objB, keysA[i]) || !is(objA[keysA[i]], objB[keysA[i]])) {
return false;
}
}
return true;
}
exports.shallowEqual = shallowEqual;
//# sourceMappingURL=shallowEqual.js.map