使用JavaScript的Visual Studio代码以及TypeScript文件作为Intellisense的参考

Question

I am currently using VisualStudioCode to write a nodejs app and I'm using the doc comments to link the parameters of functions to classes so the IntelliSense can kick in, but I encountered some problems when I want to use classes/types of modules.

How I currently handle things:

class Foo{
    constructor(){
      this.bar = "value"
    }
}

/**
 * @param {Foo} parameter 
 */
function foobar(parameter){
  parameter.bar.charAt(0); //parameter.bar now with IntelliSense
}

In foobar I can now see all available attributes/functions I can call on bar .

Now, if somewhere in a node-module a TypeScript file:

declare module 'coollib' {
  namespace lib {
    type CoolLibType = {
      begin?: string | number | Date;
      liveBuffer?: number;
      requestOptions?: {};
      highWaterMark?: number;
      lang?: string;
    }
  }
  export = lib;
}

How can I reference this? I would like to do something like this in my JavaScript file:

const CoolLibType = require('coollib')
/**
 * @param {CoolLibType} obj 
 */
function foobar(obj){
  obj.lang.charAt(0); //with cool IntelliSense
}

But it obviously doesn't work like this.

Answer 1

Use what's called an import type .

/**
 * @param {typeof import('coollib')} obj
 */
function foobar(obj) {
  obj.lang.charAt(0); //with cool IntelliSense
}

Read more about import types in TypeScript 2.9 release notes .