说明: 这篇文章并不是教大家如何用和如何写设计模式,而是给大家一个参考:如何搭建一个练习的ts版设计模式库
js 的设计模式是经常使用的,但是最近在转 ts,所以就打算用 ts 重写 js 的设计模式. 说是重写其实也是模仿.
主要技术点: webpack + typescrpt + jest + ts-jest
使用 jest 测试的原因是使用和配置相对简单,并且支持 ts 文件(不需要编译成 js 文件后测试),也是 react 的推荐测试框架(毕竟 facebook 自己产品).
好了开始我们的旅程.
npm init
如下:
{
"name": "ts-design-pattern",
"version": "1.0.0",
"description": "ts design pattern",
"main": "index.js",
"scripts": {},
"keywords": ["ts", "design", "pattern"],
"author": "wwmin",
"license": "ISC",
"devDependencies": {}
}更多配置请查看npm init
cnpm i typescript jest ts-jest @types/jest --save-dev
并设置 script 后 package.json 文件如下:
{
"name": "ts-design-pattern",
"version": "1.0.0",
"description": "ts design pattern",
"main": "index.js",
"scripts": {
"test": "jest"
},
"keywords": ["ts", "design", "pattern"],
"author": "wwmin",
"license": "ISC",
"devDependencies": {
"@types/jest": "^23.3.10",
"jest": "^23.6.0",
"ts-jest": "^23.10.5",
"typescript": "^3.2.1"
}
}tsc --init
后生成 tsconfig.json 文件内容如下
{
"compilerOptions": {
"target": "es2015",
"module": "commonjs",
"strict": true,
"noImplicitAny": true
}
}更多配置请查看tsconfig.json
npx ts-jest config:init
后生成 jest.test.js 文件内容如下
module.exports = {
preset: 'ts-jest',
testEnvironment: 'node',
};更多配置请查看ts-jest
| .gitignore
| jest.config.js
| package.json
| README.md
| tsconfig.json
|
+---src
| Adapter.ts
|
\---test
Adapter.test.ts
整体文件夹结构大致就是这样, 这里也把.gitignore 内容放上,方便大家参考
.DS_Store
node_modules/
/dist/
npm-debug.log*
yarn-debug.log*
yarn-error.log*
# Editor directories and files
.idea
.vscode
*.suo
*.ntvs*
*.njsproj
*.sln
*.mapsrc 下和 test 的文件是完成的代码
在 src 下新建 Adapter.ts
代码如下:
interface MediaPlayer {
play(type: string, fileName: string): void;
}
interface AdvanceMediaPlayer {
playVlc?(fileName: string): void;
playMp4?(fileName: string): void;
}
class VlcPlayer implements AdvanceMediaPlayer {
playVlc(fileName: string) {
console.log("playing vlc file......." + fileName);
}
}
class Mp4Player implements AdvanceMediaPlayer {
playMp4(fileName: string) {
console.log("playing mp4 file......." + fileName);
}
}
class MediaAdapter implements MediaPlayer {
player: AdvanceMediaPlayer;
constructor(type: string) {
// 根据type 生成哪一个播放类
if (type === "vlc") {
this.player = new VlcPlayer();
} else if (type === "mp4") {
this.player = new Mp4Player();
} else {
this.player = new Mp4Player(); // 默认使用mp4player
}
}
play(type: string, fileName: string) {
// 因为特定的播放类有特定的播放方法，所以还需要再根据type调用特定的播放类
if (type === "vlc") {
if (this.player.playVlc) this.player.playVlc(fileName);
} else if (type === "mp4") {
if (this.player.playMp4) this.player.playMp4(fileName);
} else {
return null;
}
}
}
export class AudioPlayer implements MediaPlayer {
play(type: "mp3" | "mp4" | "vlc", fileName: string): boolean {
if (type === "mp3") {
console.log("播放器内置支持mp3, " + fileName + "已开始播放.");
return true;
} else if (type === "vlc" || type === "mp4") {
let ma = new MediaAdapter(type);
ma.play(type, fileName);
return true;
} else {
console.log("不支持当前格式");
return false;
}
}
}然后创建测试文件 在 test 文件夹下新建 Adapter.test.ts 内容如下:
import { AudioPlayer } from "../src/Adapter";
test("playing to be true", () => {
let player = new AudioPlayer();
expect(player.play("mp3", "aa.mp3")).toBe(true);
expect(player.play("mp4", "bb.mp4")).toBe(true);
expect(player.play("vlc", "cc.vlc")).toBe(true);
});关于 jest 的使用请参考 jest
npm run test 或 npm test
内容如下
PASS test/Adapter.test.ts
√ playing to be true (18ms)
console.log src/Adapter.ts:49
播放器内置支持mp3, aa.mp3已开始播放.
console.log src/Adapter.ts:18
playing mp4 file.......bb.mp4
console.log src/Adapter.ts:12
playing vlc file.......cc.vlc
Test Suites: 1 passed, 1 total
Tests: 1 passed, 1 total
Snapshots: 0 total
Time: 1.002s, estimated 2s
Ran all test suites.
可以看到绿色的 passed 字样,如果测试没有通过则会有红色的错误提示.
好了,这就完成了 ts 版的设计模式库的搭建,后面我也会继续将设计模式慢慢补充完整,
代码可以参考我的github https://github.com/wwmin/ts-design-pattern