Assessing stability of new JavaScript features

Jared Wein jwein at
Thu Jun 20 22:08:31 UTC 2013

----- Original Message -----
> From: "Mike Ratcliffe" <mratcliffe at>
> To: "Gregory Szorc" <gps at>
> Cc: "Firefox Dev" <firefox-dev at>
> Sent: Thursday, June 20, 2013 6:02:02 PM
> Subject: Re: Assessing stability of new JavaScript features
> Sometimes a new feature gives you exactly what you need to get the
> job
> done. Having to check the features we are using against an ever
> changing list would be frustrating.
> My point of view is that using these methods in chrome code quickly
> reveals bugs and, ultimately, results in a more stable experience.

I agree with Mike. As front-end developers, we can help the JS team understand the pros and cons of their work quicker than most web devs.

That doesn't mean that it hasn't bit us before. The simplest example was when String.contains got backed out of beta because of issues with MooTools.

Functionally the feature was complete and working extremely stable, it just so happened that there were some JS libraries that weren't expecting the method to exist. There was no way we could predict this, unless we would have waited for the new feature to stick on Release builds.

So in conclusion, I think that we should be willing to use the new features ASAP. Most of the features, if not all, can be implemented another way if the feature disappeared, but it might not be such an elegant replacement.

Hope that helps,

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