如何在TypeScript使用模块化以及注意事项详解

myModule.ts
    export const name: number = 123
    export const getUser = (user: string): void => {
      console.log(user)
    }

index.ts
    import { name, getUser } from "./myModule";
    getUser(name)

// 导出
module.exports = {
    sum (a: number, b: numnber) {
        return a + b
    }
}

//引入
const mymodule = require('./xxx')

// 导出
exports = {
    sum (a: number, b: numnber) {
        return a + b
    }
}

//引入
import mymodule = require('./xxx')

    import fs from "fs";
    fs.readFileSync('./')

    // tsconfig.json中设置module: CommonJs, 结果如下

    exports.__esModule = true;
    var fs_1 = require("fs");
    fs_1["default"].readFileSync('./');

 import fs from "fs";

    import { readFileSync } from "fs";
    readFileSync('./')

    exports.__esModule = true;
    var fs_1 = require("fs");
    (0, fs_1.readFileSync)('./');

    import * as fs from "fs";
    fs.readFileSync('./')

    exports.__esModule = true;
    var fs = require("fs");
    fs.readFileSync('./');

tsconfig.json

{
  "compilerOptions": { 
    // 启用es模块化交互而非es模块导出
    "esModuleInterop": true
  }
}

    import fs from "fs";
    fs.readFileSync('./')

// 生成辅助函数__importDefault
// 此时如果不是属于esmodule形式导出, ts会默认添加default属性，值设置为本身
    var __importDefault = (this && this.__importDefault) || function (mod) {
        return (mod && mod.__esModule) ? mod : { "default": mod };
    };
    exports.__esModule = true;
    var fs_1 = __importDefault(require("fs"));
    fs_1["default"].readFileSync('./');