[FEATURE] Add field "preferDev" to package.json

[Ginden]

What / Why

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 without specyfing --production flag.

When

• On adding new package

Where

• npm/cli

How

Current Behavior

Packages are installed as dependencies by default.

Expected Behavior

To choose:

• Warn user about installing preferDev package as production one.
• Ask for confirmation if installing preferDev package as production one
• Require --production flag explicitly set to install preferDev package as production one

[ljharb]

Please file this as an RFC.

[Ginden]

@ljharb Where?

[ljharb]

https://github.com/npm/rfcs

[ruyadorno]

Thanks @Ginden I see you submitted an RFC. Let's follow up with the discussion over there and I'll close this issue 😊