When creating Angular 2 library npm package, should I use peerDependencies or dependencies for Angular 2 dependencies?

Question

Currently, when I create npm package for Angular 2, mainly as Angular 2 services, I use peerDependencies as follow:

  "peerDependencies": {
    "@angular/core": "^2.0.0",
    "rxjs": "5.0.0-beta.12",
    "zone.js": "^0.6.6"
  }

I don't use dependencies because I don't want my package to pull them during npm install. As I expect the target application is Angular 2.

And put all dependencies needed to compile my package in devDependencies:

  "devDependencies": {
    "@angular/core": "^2.0.0",
    "rxjs": "5.0.0-beta.12",
    "zone.js": "^0.6.6",
    "typescript": "*",
    "typings": "*"
  }

However, should I use dependencies or peerDependencies?

My main concern is for application using the package. Do they affect the build process of the consuming application?

Or am I doing it plain wrong and should switch back to dependencies?

Answer 1

From https://nodejs.org/en/blog/npm/peer-dependencies/

Peer Dependencies

What we need is a way of expressing these "dependencies" between plugins and their host package. Some way of saying, "I only work when plugged in to version 1.2.x of my host package, so if you install me, be sure that it's alongside a compatible host." We call this relationship a peer dependency.

As I interpret it, peer dependencies are simply to tell the one who's using your package that it won't work if they do not install the peer dependencies.