Does npm/yarn install devDependencies by default?

Question

I'm working on private library of react components. I've already setup the whole workflow etc. but I'm not sure about one thing.

In my library I have some packages listed as peerDependencies which have to be peer ones (for example react , cuz only one instance of react can be installed at once, otherwise everything breaks). But if I'd like to setup some tests in my library I need react installed there as devDependency .

So I have to install react as peer and dev in library. And what happens when I publish this package to npm register? devDependencies are excluded here?

Thanks!

Answer 1

If you create a node package, and you have some dev dependencies, npm wont count them for the publish. That's why it's called devDependencies . It's not under the production code.

Answer 2

I know you have to specify when installing an npm package --save-dev so it saves dependencies onto your json file.

Answer 3

If you need it in production, add it to peerDependencies . Otherwise, leave it in devDependencies . When someone installs your library, dev dependencies won't be installed, and peer dependencies should already be installed.