CODEWITHSUNDEEP
node.jstypescript
Johan Lindberg
Johan Lindberg

Reputation: 168

Typescript : How do I use "declare module" in node

How do i get declare module to work in Node, I get the typescript to compile without errors and the Intellisense in VS.Code works. But i get "Cannot find module 'messages'" in runtime.

Clarification : I´m trying to get both the api.ts and mq.ts classes under the same "namespace" messages.

I have the following node project setup.

api.ts

declare module "messages" {
export class Put {

    }
}

mq.ts

declare module "messages"{
export class GetWork {

    }
}

main.ts

import * as messages from "messages";
let x = new messages.GetWork();

tsconfig.json

{
   "compilerOptions": {
      "target": "es6",
      "module": "commonjs"
   },
   "exclude": [  ]
}

jsconfig.json

{
   "compilerOptions": {
       "target": "ES6"
   }
}

Upvotes: 2

Views: 14947

Answers (2)

Norgerman
Norgerman

Reputation: 79

In node you don't need to use declare module, every file is just a module, declare module is for d.ts and other usage.

In your case just add an index.ts under /messages directory like this and remove declare module.

import * as M1 from "./M1";
import * as M2 from "./M2";

export {M1, M2};

Upvotes: 3

thitemple
thitemple

Reputation: 6059

A few things here, because you're trying to import messages without a relative path, with just the names, what TypeScript tries to do is to find a module in a node_modules folder. That's why it can't find any.

So, if you want to import one of your own modules you should use a relative path.

Now, every file is a module. So if you have a file called mq.ts you should import it as follows: 

import { Put } from './mq';

The syntax:

declare module "messages" {
  // ....
}

is used only when creating Typings for existing node_modules and usually one would create a .d.ts file to do so.

Here's the documentation on module resolution for TypeScript, it is a good one.

Upvotes: 1

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