使用typescript在Node js中导入类

Question

I would import class in nodejs and use it in app.ts

var nano = require("nano");
import { EnvConfig } from './envConfig.service';
let config = new EnvConfig();
const dbCredentials: any = config.appEnv.getServiceCreds('dataservices');
export const nanodb = nano({
  url: dbCredentials.url,
});
export const nanodbCockpitLight = nanodb.use('data');
console.log(dbCredentials);

When I try to compile I get this error.

import { EnvConfig } from './envConfig.service';
       ^
SyntaxError: Unexpected token {

I have created the tsconfig file :

{
  "compilerOptions": {
    "module": "commonjs",
    "declaration": false,
    "noImplicitAny": false,
    "removeComments": true,
    "noLib": false,
    "allowSyntheticDefaultImports": true,
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es6",
    "sourceMap": true,
    "allowJs": true,
    "outDir": "./dist",
    //"baseUrl": "src" // Attention !! nécessite l'utilisation d'un loader de module node pour fonctionner sur node
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "**/*.spec.ts"]
}

I get this warning

No inputs were found in config file 'c:/Users/EHHD05911.COMMUN/Documents/cockpitLight/DB mananger/tsconfig.json'. Specified 'include' paths were '["src/ / "]' and 'exclude' paths were '["node_modules"," / .spec.ts"]'

Answer 1

您无法直接运行无法正常运行的节点app.ts文件。您需要像babel js或typescript编译器tsc这样的编译器，因此请先转换为js文件，然后再运行节点app.js

Answer 2

You're using .js extension, you need .ts extension, eg: app.ts instead of app.js .

Make sure you have typescript either in npm global or in dev dependencies.

Answer 3

I suspect whatever you're importing has typescript syntax (strong typing and such), and so running node directly won't work. You need to run tsc first, which will transpile everything to javascript in a dist folder, and then run node dist/app.js .

This is a bit cumbersome though, which is why there is ts-node . It's exactly what it sounds like, a node REPL for typescript. You should be able to run ts-node src/app.ts .

Answer 4

import { something } is a typescript syntax, it won't work in a .js file. That is a separate language. Try using require instead.

Answer 5

Use babel js which is a toolchain that is mainly used to convert ECMAScript 2015+ code into a backwards compatible version of JavaScript in current and older browsers or environments.

package.json

"dependencies": {
"@babel/polyfill": "^7.0.0",
}

"babel": {
"presets": [
  "@babel/preset-env"
]

},

"scripts": {
    "start": "server.js --exec babel-node",
}

https://babeljs.io/docs

This will enable/resolve your import statements.