Lint with eslint

[etpinard]

@alexcjohnson @mdtusz @cldougl @bpostlethwaite

I wanted to try eslint, and I ended up spending the whole afternoon going through its extensive set of rules and options (see http://eslint.org/docs/rules/)

It has the potential to be our one-and-only auto style guide. Consistent, non-arbitrary style rules coming the plotly.js 🎉 !

eslint is noticeably slower than jshint, so it might not be ready for live linting inside a text editor, but it is certainly ready and very useful for some pre-commit checks using npm run lint.

[etpinard]

The best part about eslint for me:

We can lint the whole project with no config repetition. eslint is smart enough to extend local and root config options.

[mdtusz]

Let's get some style in plotly.js! 💃

[etpinard]

bye bye

var someVar        = 10;
var someOtherVar   = 12;

[cldougl]

do we want the space between function and (plotname)
(sorry I think I'm a little confused with the controversial spacing rule)

[mdtusz]

Nope! Parentheses for a function should always be butted up against a name, or function.

[etpinard]

The major part of the plotly.js code has:

Object.keys(plots).forEach(function(plotname) {
    // ...
});

eslint checks it using the space-before-function-paren rule: https://github.com/plotly/plotly.js/blob/eslint/.eslintrc#L25

which isn't considered an error (yet).

[etpinard]

I'm ok adding 1 commit fixing all function () instances? That should take me ~ 20 mins.

[cldougl]

👍 @mdtusz

[cldougl]

@etpinard (for me) just wanted to make sure I was understanding that rule. I'm okay with or without the commit for all function () instances

[mdtusz]

@cldougl if you're using sublime text, you can edit your snippets to match that style using the Package Resource Viewer package - I had to change it for mine.

[cldougl]

ahh cool, I'll try that

[cldougl]

Looks good to me 💃