Template strings support in JS lexer

[everyonesdesign]

It seems that ECMAScript2015's Tempate strings breaks Babel's Javascript parsing.

That's sad, because it's supported quite well in latest browsers.

It would be great if Babel supported this feature.

[akx]

Entirely possible to implement!

There are PRs in the pipeline to improve JSX and dotted name parsing (#310 and #298 respectively).

However, a question:

Are you planning to use template strings in conjunction with translation, like

gettext(`Hi, ${name}!`)
// or to use the tag syntax,
i18n `Hi, ${name}!` 

or would you just like to see parser support for plain template strings?

[everyonesdesign]

Well, I planned to use this way:

new ScrollUp({
    text: `▲<br><span> ${ _("back to top") } </span>`
});

But, actually, it's not the best idea to put markup directly to strings.
After checking out your examples I see that the issue is not so easy to implement due to multiple usage ways.
Anyway, it would be great if there was a best practice or a recommendation on its usage and we could stick to it.

[akx]

Ah, that (parsing the ${ } expressions within templates) should also be possible to implement. I didn't think about that :)

(Mental note for implementation: Namely, before emitting a template string, find ${..} sections within it, "recursively" re-parse them as source and emit the tokens from within too.)

But sure, this definitely looks like something to implement along with the other JavaScript extraction improvements! :)

[akx]

@everyonesdesign If you're around, could you do code review on #332? :)