将 typescript 转换为 java 脚本时的奇怪行为

Question

I am trying to move my NodeJs app from Java Script to TypeScript to take advantage of some of the avail benefits. But while doing so i fail at the most simple taks..

I have this simple code below in my index.ts file. I want to import express and then start a basic listener on the port from the config file.

import {express} from 'express';
import {config} from './config/config';
    
const app = express();
const http = require('http');

const secure = http.createServer(app).listen(config.port ,()=>{
    console.log(`listening on Port ${config.port}`)
})

when i run "npm run-script build" i get the below output

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const express_1 = require("express");
const config_1 = require("./config/config");
const app = express_1.express();
const http = require('http');
var secure = http.createServer(app).listen(config_1.config.port, () => {
    console.log(`listening on Port ${config_1.config.port}`);
});

why does it prefix express and config with _1? The express_1.express seems to brake it. Hope someone can tell my why and how to avoid in future.

Answer 1

I think express module is not a named export it's a default export. for that you've to import like below to make it work.

import express from 'express';