TypeScript安装配置

一、安装

npm install typescript

二、初始化

1. 初始化命令

tsc --init

2. 编辑配置文件

// tsconfig.json
{
  "compilerOptions": {
    /* Basic Options */
    "target": "es6",                          /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017','ES2018' or 'ESNEXT'. */
    "module": "commonjs",                     /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', or 'ESNext'. */
    "allowJs": true,                       /* Allow javascript files to be compiled. */
    "outDir": "./dist",                        /* Redirect output structure to the directory. */
    "rootDir": "./src",                       /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */

    /* Strict Type-Checking Options */
    "strict": true,                           /* Enable all strict type-checking options. */
    "strictPropertyInitialization": false,  /* Enable strict checking of property initialization in classes. */

    /* Module Resolution Options */
    "esModuleInterop": true,                   /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */

    /* Experimental Options */
    "experimentalDecorators": true,        /* Enables experimental support for ES7 decorators. */
    "emitDecoratorMetadata": true,         /* Enables experimental support for emitting type metadata for decorators. */
  },
  "include": [
    "src/*",
    "src/**/*"
  ],
  "exclude": [
    "node_modules"
  ]
}

// package.json
...
"scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "tsc": "tsc",
    "tsc:w": "tsc -w"
  },
...

三、运行

（一）先编译再运行

// 1. 编译“./src”下的*.ts文件
tsc            
// 2. 运行生成的“./dist”下的*.js文件
node app.js  

（二）免编译运行

// 1. 安装ts-node
npm install ts-node -g 
// 2. 直接运行*.ts文件（类似node 运行*.js文件）
ts-node app.ts