Static console functions / binding

[terinjokes]

Right now assigning a console function to a local variable kind of sucks, since they're expected to be called within the context of console. This requires the developer to bind.

var log = console.log.bind(console);
log('＼(゜ロ＼)ココハドコ? (／ロ゜)／アタシハダアレ?');

Except this doesn't work in some versions of IE because the console functions aren't instances of Function!

var log = Function.prototype.bind.call(console.log, console);
log('(ノಠ益ಠ)ノ彡┻━┻');

Which is a lot to type for a pretty simple and common task.

var log = console.log;
log('＼(◎o◎)／！');

It makes sense to me that this is soemthing worth supporting.

[sindresorhus]

👍 This is very convenient when you want to log the output of a callback .catch(console.error) or create a shortcut const log = console.log. This is also how it works in Node.js.

[domenic]

I don't think any browsers currently support this, although Node.js does. I think it's sensible, but I think we'd have some work to do before getting it in browsers:

• Web IDL would need to be updated with some kind of [Bound] attribute. Hmm, I wonder if [Unforgeable] would work? It wasn't meant for that purpose, but seems worth checking...
• We'd need to get at least a couple browsers to implement that.

[alexkozy]

FYI.
Link to chromium discussion about this: https://crbug.com/167911
And older and more informative webkit issue: https://bugs.webkit.org/show_bug.cgi?id=20141#c40

[pwnall]

I'd be happy to try to revisit WebKit and Blink implementations for bound console.log and its siblings if the standard goes in that direction. I'm still a bit annoyed when I can't pass console.log as a callback when debugging or feeling my way around new browser features, so I'd be sufficiently motivated to get it implemented.

[paulirish]

Chrome DevTools team discussed this yesterday and it's doable though more work than it appears to be. These methods are implemented in native, rather than JS. We may fix this in the next few months, though we'd be happy for your help with it @pwnall

[domenic]

@paulirish one approach that the spec might consider is to change the IDL from

[NoInterfaceObject]
interface Console {
  void assert(boolean condition, optional any message);
  void clear();
  ...
};

partial interface Window {
  attribute Console console;
};

to

// [NoInterfaceObject is gone]
interface console { // note lowercase
  static void assert(boolean condition, optional any message);
  static void clear();
};

// no need for adding it to Window explicitly

This would change things slightly: typeof window.console === "function" would now be true, among the obvious prototype chain changes (i.e. there's no Console.prototype object). But maybe run that by your team and see what they think.

The alternative would be custom bindings of a sort.

[pwnall]

@paulirish @domenic Is this definitely going to happen in spec-land? I'm asking to make sure I don't waste effort trying to implement it. If so, I can probably find some time in the second half of February. Also, 🎆

[domenic]

@pwnall well, specs are driven by implementation willingness, so that question is kind of backward. If we can get at least two implementations to pledge to implement something then we can in good conscience put it in the spec.

[robertkowalski]

a typical chicken-egg situation. :)

@frewsxcv what do you think about it in regard to FF?

[frewsxcv]

For the record, I'm not in any way associated with Mozilla, other than occasional volunteer contributions for Servo. I'll link this thread to the Servo/Firefox people hoping someone more official will answer.

[jlongster]

Apparently we (Firefox) used to do this. I found this: https://bugzilla.mozilla.org/show_bug.cgi?id=989619

I can't speak for my team (devtools) but I bet most people would be fine with this. My coworker also filed this bug a while bug on a (seemingly defunct) different console repo: DeveloperToolsWG/console-object#27

[domenic]

OK, so as discussed in #1 (comment) and the related mailing list thread, this issue is kind of the biggest outstanding issue on this repo. And it's essentially blocked on implementer interest. Web developers really want this, as can be seen from previous discussions.

My sketch in #1 (comment) shows how this can be done without any custom IDL bindings, which should ease the burden on implementers. But we still need at the very least explicit signals from two implementers that they are willing to do the work.

It seems like from #3 (comment) there's some support from Chrome, on the timeline of a few months, and in https://lists.w3.org/Archives/Public/public-whatwg-archive/2016Feb/0007.html it seems like @bzbarsky voiced support if someone can volunteer to do the work in Firefox. I wouldn't say this is enough support to conclusively change the spec yet though... it would be different if someone from Firefox could commit to doing the work.

Any thoughts from Safari (@hober?) or Microsoft (@travisleithead?)?

[zcorpan]

If this is implementable with only copying webidl, it seems like it could be a "good first bug" for Firefox that @bzbarsky could mentor, maybe? Is there a bug filed?

Just changing the spec could also get the ball rolling...