Support optionalDependencies in the no-extraneous-dependencies rule

[sindresorhus]

I ran it on AVA and got:

  test/cli.js:19
  ✖   19:2  'chokidar' is not listed in the project's dependencies. Run 'npm i -S chokidar' to add it  import/no-extraneous-dependencies

It is defined, but as an optionalDependency: https://github.com/sindresorhus/ava/blob/c4e58e3e7eeb6b966a32a964445ac5ced813793a/package.json#L171-L173

Using master (055201e).

[benmosher]

Yeah, I suspect the peerDependencies version of this is inevitable as well (though those are often reflected in devDependencies, so maybe not).

Feels like the existing devDependencies strategy makes sense. Default to allowed, add as a flag to enforce as is if desired.

[sindresorhus]

Feels like the existing devDependencies strategy makes sense. Default to allowed, add as a flag to enforce as is if desired.

Default to allowed yes. I don't see why you would want to disallow it though? optionalDependencies are more like dependencies than devDependencies.

[benmosher]

I can imagine turning it off for tests or "critical" regions or something. Easy enough to support (maybe even easier than not).

If whoever implements this wants to leave the option off, though, I won't argue. 😎

[sindresorhus]

👍 Alright. Was just curious.

[rexxars]

What happened to the peerDependency version of this? If you don't have tests that require it, they won't necessarily be in devDependencies..?

[benmosher]

@rexxars don't think anyone is looking at it. PR welcome. 😁

[ianstormtaylor]

+1 to peerDependencies

[benmosher]

@rexxars @ianstormtaylor created #423 to track, accepting PRs 😎