RFC: add preferDev field to package.json

[Ginden]

Certain packages are used almost exclusively for development. Eg. typescript, tslint etc. It's usually a mistake to add them as normal dependencies.

I suggest to add field "preferDev": boolean (with default false) to package.json. User can't install preferDev package as production package without specifying --save-prod flag.

References

npm/cli#1337

[ljharb]

eslint presumably would preferDev, but it’s a runtime dep in standard, for example. I’m not sure package authors have sufficient context to know whether their package needs to be dev or prod.

[wesleytodd]

If this goes the direction of a warning, I would think you only show it on explicit package installs:

npm i eslint --save-prod

and not:

npm i

[isaacs]

My comments on this are essentially the same as my comments on preferPeer, for all the same reasons.

[RilDev]

Also making sure that is appears as the default install suggestion on NPM would be convenient!

Using the format npm i [package-name] -D for example.

Reddit: How To Change The Default Install Suggestion On NPM