Enforce import index style

[sindresorhus]

I want to enforce require('.'); and from '.';. Before Node.js 4 you had to do './'. In Node.js 4 you can do: '.'.

Should catch the following cases:

• './'
• './index'
• './index.js'

Should be easy to implement auto-fixing for this rule.

[sindresorhus]

I don't see the point in an option. 0.12 is already being phased out. It went into maintenance mode early this month. I'd rather have a simple rule without any options that we can add to esnext in XO for now.

[jamestalmage]

My thought is that most of what I work on still supports 0.12, and will need to for the next 12 months.

. vs ./ isn't that big of deal, but it would be nice to call out ./index and ./index.js.

Either way, the rule should also handle relative references to index.js:

• ../../index.js -> ../../

[sindresorhus]

Alright. So how about we fail on ./index and ./index.js and allow . and ./, but in a year we change it to only .?

[jfmengels]

If it gets in XO with esnext and not as the default, I don't see why it couldn't be . already. Or give it an option to prefer ./ or ., that way, we won't have to change it in a year and "migrate" the codebases that use esnext.

[sindresorhus]

Or give it an option to prefer ./ or ., that way, we won't have to change it in a year and "migrate" the codebases that use esnext.

I was hoping to not need an option, but I agree with @jfmengels. That sounds like the best solution. Should default to ., so we can just remove the option in a year.

[ayrton]

I wrote this earlier today for closed project, happy to open a PR:

module.exports = function(context) {
  return {
    'ImportDeclaration': function(node) {
      if (node.source.value.slice(-1) === '/') {
        context.report(node, 'Omit trailing slashes in your imports. Rename to `' + node.source.value.slice(0, -1) + '`');
      }

      if (node.source.value.match(/\/index\.js/)) {
        var index = node.source.value.indexOf('/index.js')
        context.report(node, 'Omit `/index.js` in your imports. Rename to `' + node.source.value.slice(0, index) + '`');
      }
    }
  }
}

[jfmengels]

@ayrton Great! And yes, please make a PR :)

A few remarks already though:

• We would like support for require too
• You don't handle the case of ./index

Thanks for doing this!

[sindresorhus]

That would be great! :)

Also needs to handle require().

[jfmengels]

@ayrton Are you still up for making a PR for this? No worries if you are not.

[ayrton]

@jfmengels I'm currently on holiday - so wouldn't mind if someone took over. Won't be able to work on it for another two weeks.

[jfmengels]

@ayrton Sure, no problem. Maybe I'll tackle this, maybe I won't, you'll see when you come back 😄 Enjoy the holidays!

Now that I think about it and that we've worked with eslint-plugin-import a bit, I think this would be a better fit there. What do you think @benmosher?

[benmosher]

Sounds like: import-js/eslint-plugin-import#394 which I'm up for.

I skimmed this thread, but is what you're looking for applicable only to . or also ./foo?

[jfmengels]

Hah. I actually 👍'd that one. Totally slipped my mind.

Originally, this issue is only for the index of the current folder.

Now that you mention it, the same will be applicable to the parent (or its parent, etc.) .. vs ../.

I'd make this more generic and also apply it to ./foo, to prevent ./foo/, ./foo/index or ./foo/index.js, but the index (also parent index?) is a bit special as . is not valid in 0.12.

[benmosher]

I'd be inclined not to support 0.12 since it's August, now. The majority of this thread is from before 0.12 phased into maintenance mode, IIRC. I could go either way, though. Would probably want the default to be 0.12-ignorant and put ./+../ exceptions behind a flag, if anything, just for consistency.

[sindresorhus]

No point in supporting nor having an option for 0.12 at this point. Really! Even ESLint has dropped support for it.

[jfmengels]

True. And if it does, they can disable this rule. 👍

@sindresorhus Does that mean you'll start writing packages in Node v4 ES6 code from now on? Or soon?

[sindresorhus]

@jfmengels I've been writing new modules with Node.js 4 as target for a while now.