Firefox Replay • Hacker News Board

Re: Firefox Replay

#181

Post by deedree » Thu, Nov 28, 2019, 4:56 PM UTC

What would apple have to do to let us have this on iOs? I would love to have a choice of browser on my phone.

Re: Firefox Replay

#182

Post by request_id » Thu, Nov 28, 2019, 4:58 PM UTC

XaspR8d wrote: post #161

barkingcat wrote: post #154

Earlier quoted context omitted.

People on HN don't like anything.

Speaking of which, I'm a little shocked to see a Mozilla thread that doesn't yet mention Pocket or the rebranding or DoH. That must mean we are in a good mood?

We're busy prepping to argue about UBI at Thanksgiving dinner.

Re: Firefox Replay

#183

Post by purple_ducks » Thu, Nov 28, 2019, 5:02 PM UTC

bogwog wrote: post #171

Maybe once they figure out how to monetize the data

Chrome's dev tools are so far beyond the competitions that this joke is a non-starter.

When Chrome does add this capability(strange they haven't added it to date given the prior art from years ago), I can see it being used by actual devs inside Google and thus being actually useful.

Contrast that with Firefox dev tools which seem to fall behind the priority list compared to new shiny flashy tech projects they concoct.

Re: Firefox Replay

#184

Post by shepardrtc » Thu, Nov 28, 2019, 5:03 PM UTC

Is it not appearing for anyone else? I downloaded it (for MacOS), and that option does not exist.

Re: Firefox Replay

#185

Post by somebodythere » Thu, Nov 28, 2019, 5:03 PM UTC

leevlad wrote: post #159

_bxg1 wrote: post #157

Very cool, but I'd much prefer they spend their time bringing Firefox's dev tools up to par with Chrome's first. I've tried several times to switch to FF completely, but every time I end up switching back on my work computer because of the dev tools.

Curious to hear what's missing. I do some light front-end work (css/react) and have been fully on Firefox for about a year. Haven't looked back.

For some reason I can't figure out how to place breakpoints at all in react/webpack code. I still switch to Chrome to do that.

Re: Firefox Replay

#186

Post by implicit » Thu, Nov 28, 2019, 5:05 PM UTC

cocochanel wrote: post #57

inglor wrote: post #35

This is a pretty nice comment from the source that explains how it works: https://github.com/mozilla/gecko-dev/blob/11d9c7b7fa82fdfb8a... ``` // Recording and replaying works by controlling non-determinism in the browser: // non-deterministic behaviors are initially recorded, then later replayed // exactly to force the browser to behave deterministically. Two types of // non-deterministic behaviors are captured: intr…

What is non-determinism in the browser?

Nondeterminism is every place where information can enter your program from the outside world.

It's random numbers, the system clock, data off the internet, and input events from the user.

What it sounds like is that Mozilla has come up with a debugging environment that bottles all that nondeterminism up into a neat little package so that it can replay a specific run of your program any time you want.

Re: Firefox Replay

#187

Post by hyt7u » Thu, Nov 28, 2019, 5:09 PM UTC

Just tried it out, and performance seems really bad at the moment, to the point where I couldn't tell if it was working properly. Does anyone have any suggestions of sites to try this on?

Re: Firefox Replay

#188

Post by sigspec » Thu, Nov 28, 2019, 5:18 PM UTC

request_id wrote: post #182

XaspR8d wrote: post #161

Earlier quoted context omitted.

Speaking of which, I'm a little shocked to see a Mozilla thread that doesn't yet mention Pocket or the rebranding or DoH. That must mean we are in a good mood?

We're busy prepping to argue about UBI at Thanksgiving dinner.

Oh man. Now I really want to tell the wife to turn the car around.

Re: Firefox Replay

#189

Post by jasonlaster11 » Thu, Nov 28, 2019, 5:24 PM UTC

BoppreH wrote: post #90

inglor wrote: post #35

This is a pretty nice comment from the source that explains how it works: https://github.com/mozilla/gecko-dev/blob/11d9c7b7fa82fdfb8a... ``` // Recording and replaying works by controlling non-determinism in the browser: // non-deterministic behaviors are initially recorded, then later replayed // exactly to force the browser to behave deterministically. Two types of // non-deterministic behaviors are captured: intr…

Sounds like Mozilla is applying the concepts they developed for their C/C++ debugger, rr ( https://rr-project.org ).

That's exactly right

Brian Hackett collaborated early on with ROC. Here are the basic principles of Replay (https://developer.mozilla.org/en-US/docs/Mozilla/Projects/We...).

In a nutshell, replay records Firefox's OS system calls, so that that Firefox can read from the recording when replaying.

Re: Firefox Replay

#190

Post by [deleted] » Thu, Nov 28, 2019, 5:27 PM UTC

purple_ducks wrote: post #183

bogwog wrote: post #171

Maybe once they figure out how to monetize the data

Chrome's dev tools are so far beyond the competitions that this joke is a non-starter. When Chrome does add this capability(strange they haven't added it to date given the prior art from years ago), I can see it being used by actual devs inside Google and thus being actually useful. Contrast that with Firefox dev tools which seem to fall behind the priority list compared to new shiny flashy tech projects they concoct…

[deleted]