feat(import): enforce no extensions for js files

[bobylito]

As reported by @samouss we lack consistency in projects for extensions when importing files. Some projects suffers more from it than others (eg. instantsearch.js).

This rules forces to remove the extensions when importing js files.

Those were valide before:

import lib from './lib.js';
import lib2 from './otherLib';

Now:

import lib from './lib.js'; // 🙅‍♂️
import lib2 from './otherLib'; //  ✅

Related to algolia/instantsearch#3022

[Haroenv]

I actually think we could go the other way (browsers require extensions)

[samouss]

I agree with your @Haroenv but it's a huge change to do in all our codebase. I doubt it's the right time to do it (it not fixable with --fix for now). At least with this rule we are consistent in all our lib. We can chose to switch this value later. WDYT?

[francoischalifour]

I agree with you, @samouss.

[bobylito]

Those rules are not set in stone and we can definitely review them after a while when the time is right.

In this case, I agree with @samouss that in-browser usage of modules is not at its prime-time and the impact is more containable.

[bobylito]

This is stuck. Can we move forward @Haroenv ?

[Haroenv]

thought upvote was clear enough, fine for me

[bobylito]

Thanks for the heads-up 😀