若川说"可能是历史上最简单的一期omit.js"源码共读,但我学到了这些

1、准备源代码
2、了解package.json依赖
3、omit方法解析
4、将原来的单元测试修改为jest
5、让项目支持typescript
6、npm publish实践
7、总结

// 浏览器打开源码地址
https://github.com/benjycui/omit.js
//点击`fork`，复制一份代码到自己的仓库
git clone git@github.com:aehyok/omit.js.git
//通过vscode打开项目后，安装依赖
npm i
// 安装完依赖后，执行测试用例
npm run test

"compile": "father build",
"prepublishOnly": "npm run compile && np --yolo --no-publish",

function omit(obj, fields) {
  // eslint-disable-next-line prefer-object-spread
  const shallowCopy = Object.assign({}, obj);
  for (let i = 0; i < fields.length; i += 1) {
    const key = fields[i];
    delete shallowCopy[key];
  }
  return shallowCopy;
}
export default omit;

npm i jest -D

npx jest --init

"test": "jest",
// 之前是
father test

npm i babel-jest @babel/core @babel/preset-env -D

// babel.config.js
 module.exports = {
  presets: [
    [
      '@babel/preset-env',
      {
        targets: {
          node: 'current',  //针对当前node版本进行编译，删除该行可能导致`npm start`报错
        },
      },
    ],
  ],
};

// import assert from 'assert';
import omit from '../src';
describe('omit', () => {
  it('should create a shallow copy', () => {
    const benjy = { name: 'Benjy' };
    const copy = omit(benjy, []);
    expect(copy).toEqual(benjy)
  });
  it('should drop fields which are passed in', () => {
    const benjy = { name: 'Benjy', age: 18 };
    const target1 = omit(benjy, ['age'])
    const target2 = omit(benjy, ['age', 'name'])
    expect(target1).toEqual({ name: "Benjy"})
    expect(target2).toEqual({})
  });
});

export const sum = (x, y) => {
  return x + y;
}

import omit, { sum } from '../src';
describe('sum', () => {
  it('两数字之和', () => {
    expect(sum(3,4)).toEqual(7)
  })
})

collectCoverage: true,
  coverageDirectory: "coverage",

npm i -D typescript

npx tsc --init

npm i -D ts-jest

module.exports = {
  preset: 'ts-jest',
  // ...
};

function omit(obj: Object, fields: string[]) {
  // eslint-disable-next-line prefer-object-spread
  const shallowCopy: any = Object.assign({}, obj);
  for (let i = 0; i < fields.length; i += 1) {
    const key = fields[i];
    delete shallowCopy[key];
  }
  return shallowCopy;
}
export const sum = (x: number, y: number) => {
  return x + y;
};
export default omit;

npm i -D @types/jest

"name": "aehyok.omit.js",