feat: object.is

README.md

@@ -56,6 +56,8 @@ We welcome all contributions. You can submit any ideas as [pull requests](https:
 
   - [ ] Object
 
+    - [x] is
+
 - [ ] ES6
 
   - [ ] Promise

src/Array/isArray/index.ts

@@ -2,7 +2,7 @@
  * @Author: Rainy
  * @Date: 2019-11-14 19:25:01
  * @LastEditors: Rainy
- * @LastEditTime: 2019-11-21 19:08:54
+ * @LastEditTime: 2019-12-02 20:16:48
  */
 
 import { isAbsType } from '../../utils/type';

src/Object/is/README.md

@@ -0,0 +1,22 @@
+### 原理
+
+Object.is() 判断两个值是否相同. 如果下列任何一项成立, 则两个值相同：
+
+- 两个值都是 undefined
+- 两个值都是 null
+- 两个值都是 true 或者都是 false
+- 两个值是由相同个数的字符按照相同的顺序组成的字符串
+- 两个值指向同一个对象
+- 两个值都是数字并且
+  - 都是正零 +0
+  - 都是负零 -0
+  - 都是 NaN
+  - 都是除零和 NaN 外的其它同一个数字
+
+这种相等性判断逻辑和传统的 `==` 运算不同, `==` 运算符会对它两边的操作数做隐式类型转换(如果它们类型不同), 然后才进行相等性比较, (所以才会有类似 `""` `==` `false` 等于 `true` 的现象), 但 `Object.is` 不会做这种类型转换. 
+
+这与 `===` 运算符的判定方式也不一样. `===` 运算符(和`==` 运算符)将数字值 `-0` 和 `+0` 视为相等, 并认为 `Number.NaN` 不等于 `NaN`. 
+
+### 参考资料
+
+[Object is](https://developer.mozilla.org/zh-CN/docs/Web/JavaScript/Reference/Global_Objects/Object/is)

src/Object/is/__tests__.ts

@@ -0,0 +1,44 @@
+/*
+ * @Author: Rainy
+ * @Date: 2019-11-14 19:25:01
+ * @LastEditors: Rainy
+ * @LastEditTime: 2019-12-02 20:28:56
+ */
+
+import { _is } from '.';
+
+test(`is('foo', 'foo') should true`, () => {
+  expect(_is('foo', 'foo')).toBe(true);
+});
+
+test(`is([], []) should false`, () => {
+  expect(_is([], [])).toBe(false);
+});
+
+const u1 = { name: 'Rain120' };
+const u2 = { name: 'Rain120' };
+
+test(`is(u1, u1) should true`, () => {
+  expect(_is(u1, u1)).toBe(true);
+});
+
+test(`is(u1, u2) should false`, () => {
+  expect(_is(u1, u2)).toBe(false);
+});
+
+test(`is(null, null) should true`, () => {
+  expect(_is(null, null)).toBe(true);
+});
+
+test(`is(0, -0) should false`, () => {
+  expect(_is(0, -0)).toBe(false);
+});
+
+test(`is(0, +0) should true`, () => {
+  expect(_is(0, +0)).toBe(true);
+});
+
+
+test(`is(NaN, 0 / 0) should true`, () => {
+  expect(_is(NaN, 0 / 0)).toBe(true);
+});

src/Object/is/index.ts

@@ -0,0 +1,13 @@
+/*
+ * @Author: Rainy
+ * @Date: 2019-11-14 19:25:01
+ * @LastEditors: Rainy
+ * @LastEditTime: 2019-12-02 20:32:37
+ */
+export function _is(source: any, target: any): boolean {
+  if (source === target) {
+    return source !== 0 || 1 / source === 1 / target;
+  } else {
+    return source !== source && target !== target;
+  }
+}

src/call/index.ts

@@ -2,10 +2,10 @@
  * @Author: Rainy
  * @Date: 2019-11-14 19:25:01
  * @LastEditors: Rainy
- * @LastEditTime: 2019-11-22 11:19:18
+ * @LastEditTime: 2019-12-02 20:02:34
  */
 
-import { ObjectMap } from '../types/index';
+import { ObjectMap } from 'types';
 
 // @ts-ignore
 Function.prototype._call = function(context: ObjectMap<any>, ...arg: any): any {

tsconfig.json

@@ -42,6 +42,7 @@
     "moduleResolution": "node",            /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
     "baseUrl": "src/",                       /* Base directory to resolve non-absolute module names. */
     "paths": {
+      "src/*": ["src/*"],
       "types/*": ["types/*"],
       "utils/*": ["utils/*"]
     },                           /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */

zh-CN.md

@@ -56,6 +56,8 @@
 
   - [ ] Object
 
+    - [x] is
+
 - [ ] ES6
 
   - [ ] Promise