TypeScript: How to define custom typings for installed npm package?

33
votes

I like to use rx-node within TypeScript

import RxNode from 'rx-node';

I installed rx-node using npm

$ npm install rx-node --save

I searched for type definitions, but without any result

$ typings search rx-node
No results found for search

How can I define custom type definitions for the installed npm module rx-node? Where should I store the type definition file? How to configure TypeScript (tsconfig.json and typings.json)?

Edit: Thanks to Aleksey L. and David Bohunek I achieved to define a rx-node.d.ts that looks like this

declare module "rx-node" {
  import {Observable} from '@reactivex/rxjs';
  import {ReadLine} from "readline";

  function fromReadLineStream(stream: ReadLine): Observable<string>
}

I installed @reactivex/rxjs

npm install --save @reactivex/rxjs

Since I got an error

node_modules\@reactivex\rxjs\dist\cjs\Observable.d.ts (10,66): Cannot find name 'Promise'. (2304)

I changed the target in tsconfig.json to es6.

3
node.jstypescripttypescript1.8

3 Answers

32
votes

Beware, this is old question (2016) regarding managing definitions using typings which is deprecated in favor of installing them straight via npm

You can add custom definitions to typings.json. For example having following folder structure:

/typings
    /custom
        rx-node.d.ts
    /global
        ...

where rx-node.d.ts is your custom typings file. For example:

declare module RxNode {
    export interface ...
}

Then install with a command

typings install file:typings/custom/rx-node.d.ts --save --global

Or manually: in typings.json add reference to this typings file:

{
    "name": "TestName",
    "version": false,
    "globalDependencies": {
        "rx-node": "file:typings/custom/rx-node.d.ts"
    }
}

And run typings install

1
votes

Create a new file, called it rx-node.d.ts and make sure it's referenced in your tsconfig.json either directly or from another file, for example typings/index.d.ts. Then you can start with something like this:

///<reference path="rx.d.ts" />

declare namespace RxNode  {

    export interface Emitter<T>{

    }

    export function toEventEmitter<T>(observable: Rx.Observable<T>, eventName: string): Emitter<T>;
}

This question/answer might be helpuful: How to write d.ts file from existing .js file?

If you create a nice, high quality typings definition file, contribute to https://github.com/DefinitelyTyped/DefinitelyTyped

0
votes

For ReactJS projects using create-react-app (react-scripts), you can add a module declaration in src/react-app-env.d.ts for your untyped package.

declare module "not-typed";

Note: in future the location of this file may change, see this issue.