40 ms·

Firefox Replay

1596 points by nachtigall 7y ago

strombofulous 7y ago
Ooooh wow. This might be enough to get me to use Firefox to develop with. This could be huge for its market share, a big part of the reason chrome was able to become so popular was because of how good its devtools were (compared to the competition at the time). Firefox definitely managed to catch up but not before lots of devs switched to chrome and stopped checking for compatibility with Firefox.
- aspaviento 7y ago
  There are still a lot of QoL features that Firefox DevTools misses. For example autocomplete for CSS classes, a tab for handling Service Workers, commands to perform actions (like disabling JavaScript), etc. I find myself switching between browsers just to take advantage of the different features each one provides which is slighly annoying. I would sincerely love some kind of unified DevTools.
  - Vinnl 7y ago
    Yeah, and vice versa as well, of course - for example, I don't think the Chrome DevTools tell you why certain CSS declarations do not apply. That said, the Firefox DevTools have been progressing really fast since the rewrite to React was completed, so I'm hopeful that it'll practically be the unified DevTools soon.
    - ivanovb 7y ago
      One reason that I use Firefox DevTools mostly is because in the inspector it shows you what events are attached to a DOM element. It's really helpful for debugging legacy applications. Sure, Chrome has something similar but it's a bit more hidden.
  - chabad360 7y ago
    Firefox sure has CSS auto-complete (at least in the inspector).
- paulintrognon 7y ago
  Do you really think the web developpers that use advanced dev tools can make a real difference in their market share? (real question)
  - albertgoeswoof 7y ago
    It happens because applications will stop working on chrome if developers never test on it. The recommendation when a user hits a bug will be to check it in Firefox and slowly Firefox will become the reliable/advanced/working option. It’s happened with IE, Chrome before and will swing back away from Chrome eventually.
    - laumars 7y ago
      IE was stagnant and shit, Chrome isn't. I may not like the Chrome monoculture happening at the moment but that doesn't mean Chrome is the same dumpster fire that was IE. And Google are hardly going to let Chrome stagnate when Chrome is the perfect vehicle to local users into Google's non-free ecosystem (I say "non-free" because you pay with your privacy)
      - wizzwizz4 7y ago
        You don't just pay with your privacy. It's not a one-way street. Google's knowledge about you feeds back to you, as they attempt to manipulate you in the way that best increases the money they receive from their advertisers. But if we want people to stop being locked into Chrome, the best way is to cease to support it. If stuff works in Chrome, that'll be because Chrome supports web standards properly, and not because there's some proprietary random Google standard-they-just-came-up-with that it relies on. (I'm looking at you, <portal>.) Don't contribute code to Chromium; instead, contribute it to a popular fork (like ungoogled-chromium), or a different browser altogether. Until Chromium is a less-centralised project, you're pretty much just giving a competitive edge to Chrome, and hence Google's near-monopoly on the web, without Google having to put in the resources to do it themselves. You're working for Google for nothing.
  - realusername 7y ago
devit 7y ago
Why "Download Firefox Nightly for macOS"? Is it not supported on Linux and Windows? Why?
- phoe-krk 7y ago
  https://developer.mozilla.org/en-US/docs/Mozilla/Projects/WebReplay https://developer.mozilla.org/en-US/docs/Mozilla/Projects/We... > Currently only macOS is supported. As for why - no idea.
  - propelol 7y ago
    It's probably because its cheaper, and most web developers are using macOS anyway
    - la_fayette 7y ago
      Have been working in web development for years, also with many coworkers. I don't know anybody with macOS except design people...
      - hellofunk 7y ago
        That’s interesting, since nearly all of the developers I know working full stack are using a mac. Maybe it’s a regional thing.
      - coldtea 7y ago
        Seen any web conference where a crapload of people (including many/most of the speakers) didn't have a MacBook? So, while it might be far less in the general market share, and even web dev share, it's more in the "kind of developer that goes to conferences/presets/etc" share...
    - jeroenhd 7y ago
      Of all developers I know, only 2 prefer macOS (in general). Most people are either on Windows or their favourite flavour of Linux. These are not just web developers though, they're full stack developers; perhaps pure frontend developers are more prone to use Apple products?
Blaiz0r 7y ago
This looks great, it's good to see that Firefox is pushing new dev features, instead of playing catch-up to Chrome. Does Replay work on the Firefox Dev build?
- y4mi 7y ago
  Seems to be a MacOS only feature.
kevsim 7y ago
The biggest benefit for me (I think) would be if the product/design people I work with could find issues and send their recordings to me. Don't think I'll be able to convince them to switch to FF though.
- melling 7y ago
  I use Chrome, Safari, and the Firefox Nightly. Not sure why there’s so much dedication to one browser.
  - Phenix88be 7y ago
    Because they all eat a lots of RAM...
    - rutierut 7y ago
      This is a good comment, I use FF Dev and Chrome RN, the current project I'm working on is Chrome only. It's nice for context switching (docs, etc in FF, debugging & development in GC) but I was not able to do this (1y ago) on my 2013 MB Pro, it was simply to slow.
      - cm-t 7y ago
        you can right click on a tab in firefox, and switch that tab to this or that context ;)
      - melling 7y ago
        I have a 2013 Mac Book Pro with 16 GB of RAM. They all run fine at the same time. I also have Xcode and several other apps open. Don’t skimp on RAM. My next computer will have 32GB of RAM. It’ll extend the usefulness by years.
- lkschubert8 7y ago
  That is one benefit of going all in on one of the immutable state management libraries. You can maintain past states and on a bug report attach the whole history to be able to play through it.
bdibs 7y ago
Looks potentially really useful, but is it normal for them to create a whole site just for one new feature?
- mackrevinack 7y ago
  vivaldi put a ton of effort into presenting each update, fancy graphics etc, but yea creating a unique domain for a feature is pretty strange alright
- archielc 7y ago
  If it is a killer feature, and that's a marketing move - why not. Looks like that Firefox been working hard lately to change trends in browsers' market share.
saimiam 7y ago
This didn't work for me. 1. I installed the nightly build as told. 2. Open nightly build 3. Went to the "Save Recording" option 4. The first two times, I got a [javascript error] saying I could not record. 5. The remaining couple of times - after I open a "New Recording Tab", whatever that is - I didn't see the javascript error but the website whose clickthru I wanted to record using this tool didn't even load in that new recording tab. Just this morning I recorded a clickthru like caveman using Quicktime. Can't wait for FF to iron out the kinks in this feature.
- tinus_hn 7y ago
  If you’re on Windows, try the built-in Steps Recorder (formerly known as Problem Steps Recorder)
  - saimiam 7y ago
    Mac.
- jasonlaster11 7y ago
  Hmm, join us in http://devtools-html.slack.com/ http://devtools-html.slack.com/ and we'd be happy to help you debug it. If the tab crashed, you can get the report in about:crashes
  - nikivi 7y ago
    What do I do if I don't have mozilla or chromium email?
  - dependenttypes 7y ago
    Is this an official thing from mozilla? If so it is extremely disappointing that they promote slack.
  - jensv 7y ago
    If you have an @mozilla.com or @chromium.org email address, you can create a Slack account. If not it seems like you might be out of luck.
mimischi 7y ago
So in its scope this somewhat similar to Cypress.io? https://www.cypress.io/ https://www.cypress.io/
- inglor 7y ago
  I don't use Cypress anymore as it didn't work for me but doesn't look like it. This is for debugging rather than testing. Also the timeline in Cypress didn't actually work too well for us.
inglor 7y ago
Is there any way to make this work in automation? This could really help with debugging failed e2e firefox tests.
inglor 7y ago
We actually have something similar for this for tests at Testim (https://testim.io https://testim.io) but only for tests with screenshots and state. Would people be interested in us open sourcing that part for regular debugging? I have considered it but I didn't think people would be interested in using this in a non-test case.
brna 7y ago
No Linux support :(
- kreetx 7y ago
  Not Linux support yet I hope :)
ga-vu 7y ago
For those interested into how this works, look into Time-Travel Debugging and the WebReplay API
inglor 7y ago
This is a pretty nice comment from the source that explains how it works: https://github.com/mozilla/gecko-dev/blob/11d9c7b7fa82fdfb8ac2a8f0864e9d8d5fe2b926/mfbt/RecordReplay.h#L32-L73 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: intra-thread and inter-thread. // Intra-thread non-deterministic behaviors are non-deterministic even in the // absence of actions by other threads, and inter-thread non-deterministic // behaviors are those affected by interleaving execution with other threads. ```
- cocochanel 7y ago
  What is non-determinism in the browser?
  - jstummbillig 7y ago
    Inputs that are either random or subject to change (api responses, user prompts i.e.)
  - correct_horse 7y ago
    Based on the grandparent, it sounds like race-conditions and random number generation fit the bill.
  - gitgud 7y ago
    My guess is that "optimisations" (shortcuts) in calculating the final layout, mean that the final layout is not entirely deterministic. It probably varies slightly, due to the entangled nest of dependencies that is responsive HTML rendering...
  - janpot 7y ago
    I don't know but if I had to guess: order of responses coming in from the server, interleaved with timer events and user events.
  - 7y ago
sandGorgon 7y ago
is this like Postman ?
- lovasoa 7y ago
  No it is not. It is a browser feature that allows rewinding to a previous state of a webpage. There is much more to that than recording and replaying HTTP requests.
Shaaaaaaare 7y ago
Looks interesting but too bad it only supports overpriced macs making it useless
aphroz 7y ago
While Microsoft is making great effort towards opening, it is sad to see Firefox develop a feature working on Mac OS only. This is terrible because you might argue that this is the same as a feature working on Windows only, but Windows can run on different hardware manufacturer. This is like a double closing. I am on Linux and I will uninstall Firefox as a repercussion hoping it will have an impact. Too bad for the last hope for a chrome alternative.
- Aeolun 7y ago
  Don’t you think that’s a bit of an overreaction? Maybe it cannot work on anything but OSX?
  - aphroz 7y ago
    Yes it is an overreaction. Whenever I see something working on Mac OS only I can't help myself but think that something went wrong in IT since 2000.
- senko 7y ago
  > Firefox develop a feature working on Mac OS only. Looks to me like this is an experimental feature in Nightly. If it's highly system-dependent I can't blame them for testing the feedback as early as possible, before other systems are supported. Question for Mozilla people here, if anyone sees it - is there a plan to bring this feature across all systems in time for regular Firefox release?
  - IainIreland 7y ago
    Last I heard, WebReplay was not on an official roadmap (in the sense that we do not yet have a target date for shipping it in release). That said, I'm pretty sure that the macOS-only restriction is just because that's what the primary developer is using, and it's a higher priority to get the system-independent parts working first. If/when WebReplay is ready to ship, I can't imagine a world where support isn't eventually added for Windows/Linux (although it could be a phased rollout, like WebRender).
- 7y ago
sdan 7y ago
How is this different from recording in Chrome Web Dev tools? To be clear, I use both Chrome and Firefox for development but just to the surface level, so I'm probably missing the point here.
- Vinnl 7y ago
  I'm not too familiar with "recording in the Chrome devtools", but this allows you to actually step back as well as forward in the debugger, e.g. for inspecting the value a variable had when code executed before.
ManlyBread 7y ago
This looks pretty good. Are there any other tools like this for different platforms? I'd be especially interested in something like this for the .NET ecosystem.
- Vinnl 7y ago
  I'm not familiar with .NET, but I think both the Elm devtools and Redux devtools can do something similar, although limited to their own features.
Roark66 7y ago
They should've put this note at the very top of the page: "Mac OS only for now!". What is the point of promoting this to everyone at this stage?
- asutekku 7y ago
  Why not? A huge portion of developers uses Macs and windows support is coming at some point. Better to get an actual feedback from the developers.
  - bflesch 7y ago
    How about linux users?
    - jackcodes 7y ago
      You’ve got to accept the fact they want to collect feedback from other users first and not you.
      - madeofpalk 7y ago
        From some users first, even if that doesn't include you
        hinkley 7y ago
        No, specifically him. I’ve heard talk. I dunno what he did but he should apologize already.
    - kibwen 7y ago
      Extremely featureful debuggers such as this one tend to require a great deal of code that is hardware-specific, in addition to being OS-specific. I assume MacOS was targeted first because it's the platform with the greatest degree of hardware uniformity. I fully expect Linux support to materialize someday, but with the caveat that I expect it will only (officially) work with the most popular hardware.
aedron 7y ago
I am not primarily a web developer, but I guess I don't really see it. I suppose 'rewind' would mostly be useful for Javascript applications? But in Javascript you can already debug pretty well. It's been a while, but I suppose Javascript debuggers can drop frames, like debugging other languages, so you already have a kind of rewind? Does anyone have a good example use case for this?
- Vinnl 7y ago
  I'm not quite sure what "drop frames" means in this context, but a use case would be stepping through the debugger, realising that the problem might be in a piece of code that has already executed, and wanting to inspect the value of a variable at that point in time. Or even more mundane: accidentally hitting "Step over" twice in a row.
  - aedron 7y ago
    In most debuggers you can drop back up the stack to the code that called the function you are currently in, and thus debug through the function call again. Example: https://stackoverflow.com/questions/2367816/when-using-the-java-debugger-in-intellij-what-does-drop-frame-mean https://stackoverflow.com/questions/2367816/when-using-the-j... "Using the "Drop Frame" functionality you can "fall back" to a previous stack frame, in a sense going back in time."
    - nemetroid 7y ago
      That Stack Overflow answer is poorly worded though, looking at an outer stack frame is really nothing like going back in time. Going back in time in the Firefox Replay sense means reversing execution of the program, e.g. to find the values of variables that have been mutated or gone out of scope.
      - aedron 7y ago
        But that's what drop frame does - it goes back to the state before your current function call, including resetting variables. It does not revert global state (like static variables) but it is essentially like reverting execution 95% of the times I use it.
wruza 7y ago
As a former gnu/linux user, I see no point to have it on a desktop. Gnu is happy to live under c:/MSYS2, and ‘linux’ part was never good at desktop-home hardware anyway. These 1.77% are barely justified as an option, imo.
- WanderPanda 7y ago
  After struggling with GPU drivers, again, the last couple of days, I could not agree more!
  - adam12 7y ago
    I'm assuming these were the closed source proprietary GPU drivers.
  - dharmab 7y ago
    I assume this was nvidia. AMD and Intel drivers are finally in a good state but nvidia is as bad as ever.
- teddyh 7y ago
  > As a former gnu/linux user, I see no point to have it on a desktop. Except, of course, software freedom.
  - jhasse 7y ago
    Which Mozilla doesn't care that much about.
- akvadrako 7y ago
  True, Linux on desktop sucks out of the box. But Windows and Mac suck and it’s not possible to make them good. Personally, I just switched back to Linux after 10 years on Mac. It’s a rough start but now it’s better than Mac and I can continue building the environment I want.
- davidy123 7y ago
  I don't know what you're talking about. I've used Debian, then Ubuntu for decades. I'm lucky I don't need the few commercial apps that hold people back, so I get the advantages of everything just working, with a good package system that whole time. These days so much is available in the browser or distributed systems, it's even easier. As for 1.77% (excluding ChromeOS and Android based desktop apps, of course), I'm going to guess those people are more significant in terms of software development and user advocacy, on their own and in networks, than the bulk of users. Certainly constantly compromising and taking the enclosed garden path has its drawbacks for the larger community.
tenryuu 7y ago
Regarding Mac OS: looks like, on Windows FF Developer Edition I can access it's UI from creating a boolean in about:config named devtools.recordreplay.enabled A new option in settings will be added to enable a Toolbox Button named "Enable WebReplay", but pressing that button will replace the entire tab content with an about:blank
softwarelimits 7y ago
Can I add a little bit of randomness to this?
Etheryte 7y ago
If this works well, it could eventually be a very big boon for Firefox in the business world. Q&A can now send reproducible bug demos to development. Technical clients can do the same. I wouldn't be surprised if someone built tooling to map these recordings into automated tests either: expect the given recorded workflow to not throw errors. I can't quite remember when I had a bug where a tool like this would've been useful, but I'm sure I would've been (and will be) very thankful for it.
- sequoia 7y ago
  Oh yeah, wow. Having bug reports come with a replayable & inspectable recording of the user's session would be an absolute game changer. We approximate this now with telemetry tools that allow you to see what the user was doing (sort of), but this would be 100x better.
  - tln 7y ago
    I wonder how often the bugs will be so deep that something like LogRocket won't be enough.
- jasonlaster11 7y ago
  Thanks for the feedback! Our #1 use-case at the moment is bug reports with a recording attached. We think that will really help when it comes to understanding the specifics of a bug when STRs are often not clear.
asaddhamani 7y ago
I would love to give Firefox a shot, but there's one thing I've had issues with, when working with projects using things like webpack, when there's an error, Chrome links me back to the original file and line, I never seem to be able to do this in Firefox. Makes it so much harder to debug things. Am I doing something wrong, or is there a way to fix this?
- Vinnl 7y ago
  Not sure how long ago you tried, but in one of the recent Firefox versions, they greatly improved the source map support - so it might just be that you should give it another try.
  - asaddhamani 7y ago
    I've tried it with the latest versions (as of now), but it doesn't seem to match up with how good Chrome is at it. I've tried both normal Firefox and the developer version. Why is this something Firefox seems to be struggling with? All the Blink based browsers seem to be much better in this regard.
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markdog12 7y ago
Really hope they can get this working with WebGL
Abishek_Muthian 7y ago
Must admit, I've used screen recording during web development for some edge cases; this might address those situations
danShumway 7y ago
My first thought is I'm mildly skeptical that this will end up being granular enough or detailed enough to actually be useful in practice, but if it does, it could be very useful. I'm pretty happy to see Firefox pushing its dev tools in this direction. They've done a really great job with layout and styling tools, but their JS dev tools have lagged behind Chrome's. So even if this particular effort doesn't pan out for some reason, it's still very encouraging. They're not just carbon-copying Chrome, and they're not just sitting back and ignoring the dev tools; they're trying to push them forward in some interesting ways.
_bxg1 7y ago
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.
- udfalkso 7y ago
  I recently switched back to FF after many years on chrome and find the dev tools to be as good of not better this time around. Curious which tools in particular you find worse? When was the last time you tried?
  - _bxg1 7y ago
    You know, as I'm going back and trying to come up with specific points, I'm having a hard time. Partly it's little usability things: - There was one time when an HTTP request was failing and I couldn't figure out why, and in the Network tab Firefox wouldn't show any information about it, even the request that went out (other than the URL), whereas Chrome not only showed the headers, it surfaced that it was a 404. - There's no way to view all source files. You have to go to "Style Editor" for stylesheets and "Debugger" for JS files. I'm not sure how to view the other files that were loaded, outside of the Network tab. - I do enjoy how Chrome's inspector puts the box layout directly above the computed styles, instead of in a separate tab. Those all feel like nitpicks, though. It could just have more to do with me not being used to it. Maybe I haven't given it enough of a chance and should give it another try.
    - bogwog 7y ago
      FF's tools used to be pretty bad compared to Chrome's, and while my main browser has always been FF I always keep Chrome around for development purposes. Lately though I haven't found myself needing to switch over to Chrome for anything devtools related. This new replay feature makes FF even more compelling (once it comes to Linux that is). So if you haven't used FF for development recently, you should definitely give it a try.
smnrchrds 7y ago
Is there a replaying debugger for reverse-engineering dotNet programs?
jrm2k6 7y ago
It might just be me but enabling the option and clicking and the recording button just attempt to reload the page and I get a blank page. Not sure what is supposed to happen.
- plorntus 7y ago
  Yeah happens to me too, guess either I'm missing an obvious button or it's slightly broken on some machines (which is to be expected).
bogwog 7y ago
Maybe once they figure out how to monetize the data
- purple_ducks 7y ago
  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 7y ago
    [deleted]
  - chinhodado 7y ago
    Don't know why you're downvoted but you're totally right. FF's dev tool is still very far behind Chrome's. IIRC things like websocket inspection aren't even in mainline FF yet. If people want to see many examples of what Chrome's webtool can do and FF can't, just take a look at this page "What's New In DevTools" for each Chrome release. https://developers.google.com/web/updates/2019/10/devtools https://developers.google.com/web/updates/2019/10/devtools
    - dblohm7 7y ago
      > things like websocket inspection aren't even in mainline FF yet Releasing with Firefox 71. https://hacks.mozilla.org/2019/10/firefoxs-new-websocket-inspector/ https://hacks.mozilla.org/2019/10/firefoxs-new-websocket-ins...
      - chinhodado 7y ago
        People have been asking for it for years though. IIRC Chrome has had it since at least 2012.
  - 7y ago
deedree 7y ago
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.
- saagarjha 7y ago
  It’s not going to happen; even if you could run your own browser engine on iOS this requires deep hooks into system calls and Mach messages which isn’t really something that I would see Apple letting you do.
shepardrtc 7y ago
Is it not appearing for anyone else? I downloaded it (for MacOS), and that option does not exist.
- shepardrtc 7y ago
  Wait, no, its fine. You have to go to the Web Developer tools, then settings, and then turn it on via the check box.
hyt7u 7y ago
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?
mattfrommars 7y ago
This is quiet cool! They did far better job then I would have imagined in doing myself! Ha! [Link to the editor](https://github.com/abdusamed91/realtime-codeeditor https://github.com/abdusamed91/realtime-codeeditor) I implemented it in my real time code editor coursework project where I made use of [Ace Editor](https://ace.c9.io/)'s https://ace.c9.io/)'s CRDT. The time machine slider does the job and looked remarkable when it ran.
8bitsrule 7y ago
Firefox is (mostly) a wonderful, free application. Linux is a wonderful, stable, free desktop. Strange days indeed. Just giving some thanks where it's due.
kyriakos 7y ago
Macos only for now
foobaw 7y ago
I wonder how this is positioned compared to Bird Eats Bug and LogRocket/FullStory
- makarov 7y ago
  Co-founder of Bird here. Firefox Replay seems to be focusing purely on developers, while we see usage also from PMs, QA and even customer support. So in the end developers can get more data from essentially anyone in the company. Over time we will be adding more tools for developers. It will be interesting to see how Firefox will approach this compared to us.
jasonlaster11 7y ago
Thanks for the feedback! Replay is in the user-research and validation phase and still quite experimental. firefox-replay.com is a work in progress. We're still sorting out the best way to communicate record and replay debugging and the new use cases. We'll share more on @firefoxDevTools when we have something to report.
- sfttty 7y ago
  Great work! Some insights from FANG. Two more things are necessary to make this a game changer: 1. JS level API to record RNR traces and upload them along with error reports (this will be a new W3C standard). This will be a compelling reason to include Firefox into the automation toolchain and at that point compatibility with Firefox will be mandatory. 2. JS level virtualization or sandboxing. Right now we have the iframe-level sandboxing but this granularity is too coarse because modern web apps have become really big (think of O365). We need a way to fragmentize the JS execution context into smaller docker-like sandboxes and record RNR traces for them. Rationale: big subcomponents should be isolated from each other and have separate traces. As a side effect, this new VM API will enable us to do one cool trick.
ihuman 7y ago
What's going on? I just see a block of text next to a static image. "Replay is an early experiment. We'll let you know on @FirefoxDevTools when it's ready for input."
- Kaveren 7y ago
  I think they saw that it got a lot of attention on HN and weren't in a stage with the product where they were ready for the corresponding feedback. For anyone who missed what it was, it allows you to derterministically record and replay your browsing for debugging purposes, and you can export these recordings to others.
  - ihuman 7y ago
    I just looked it up on the internet archive and saw the old website. I think they should have kept the old one, since the new website has almost no information at all. https://web.archive.org/web/20191128111509/https://firefox-replay.com/ https://web.archive.org/web/20191128111509/https://firefox-r...
    - Narushia 7y ago
      That gives me “The Wayback Machine has not archived that URL.” I also get the same for all the other snapshots, maybe Mozilla applied for a takedown? Edit: I found it on archive.is: http://archive.is/0ei35 http://archive.is/0ei35 Though it seems a bit broken.
meerita 7y ago
I can't see it. > An error occurred when connecting to firefox-replay.com. PR_CONNECT_RESET_ERROR
Karupan 7y ago
This will be an absolute game changer for web development. I am currently working on a really simplified version of this, but as a chrome extension. We deal with a lot of real time data and have been facing some timing issues (network and user input) which is really hard to reproduce. I’m going to give this a shot today!
darshan 7y ago
Mods: the link should perhaps be changed to: https://developer.mozilla.org/en-US/docs/Mozilla/Projects/WebReplay https://developer.mozilla.org/en-US/docs/Mozilla/Projects/We... This currently has 1215 points, and the link is no longer valid. It now just shows an image of Firefox's devtools and the sentence "Replay is an early experiment. We'll let you know on @FirefoxDevTools when it's ready for input." That's not useful, interesting, or informative. The MDN docs seem like an appropriate replacement.
- dessant 7y ago
  The initial version of the site gave a good overview of Firefox Replay: https://web.archive.org/web/20191128111509/https://firefox-replay.com/ https://web.archive.org/web/20191128111509/https://firefox-r...
  - varenc 7y ago
    Note: You can try out Firefox Reply on a macOS in Firefox nightly: https://www.mozilla.org/en-US/firefox/channel/desktop/ https://www.mozilla.org/en-US/firefox/channel/desktop/ Firefox removed the content that tells you this. It's odd that they did that... My guess is that all this attention was a premature launch, and they were hoping to make news with Firefox Replay later. (US Thanksgiving day isn't exactly ideal...)
    - digitarald 7y ago
      Correct on premature launch! Handling all the excitement was fun though while preparing food. There is a lot more work and research needed before rolling this out further.
      - varenc 7y ago
        Awesome job with it! The tech is fascinating. I got it working, somewhat, myself. And thanks for confirming my suspicion! It sure looked like one =)
  - 7y ago
swsieber 7y ago
Oh, oh, oh! This is so exciting! I had built a poor mans version of this where I worked with puppeteer for automated tests. It'd basically record the full dim any time it changed, along with console logs, network request metadata, images and css and output it as a test recording. You could then view that and walk through it in an Electron app. This'll blow it out of the water. I hope for e2e testing's sake that linux support comes soon.
empressplay 7y ago
Tangentially, our Apple II emulator [1] has a recording reverse-debugger, should you want to do similar to debug 6502 code... ;) Developers of recent Apple II games have been using it to resolve pesky bugs. [1] https://paleotronic.com/software/microm8/help/web-debugger/ https://paleotronic.com/software/microm8/help/web-debugger/
jv22222 7y ago
I've been working on a slightly related idea - https://speakhq.co https://speakhq.co - I did submit as a Show HN, but didn't get too much traction.
OrgNet 7y ago
Is this a rebranded Firefox Focus?

1596 points by nachtigall 7y ago

Ooooh wow. This might be enough to get me to use Firefox to develop with. This could be huge for its market share, a big part of the reason chrome was able to become so popular was because of how good its devtools were (compared to the competition at the time). Firefox definitely managed to catch up but not before lots of devs switched to chrome and stopped checking for compatibility with Firefox.

aspaviento 7y ago
There are still a lot of QoL features that Firefox DevTools misses. For example autocomplete for CSS classes, a tab for handling Service Workers, commands to perform actions (like disabling JavaScript), etc. I find myself switching between browsers just to take advantage of the different features each one provides which is slighly annoying. I would sincerely love some kind of unified DevTools.
- Vinnl 7y ago
  Yeah, and vice versa as well, of course - for example, I don't think the Chrome DevTools tell you why certain CSS declarations do not apply. That said, the Firefox DevTools have been progressing really fast since the rewrite to React was completed, so I'm hopeful that it'll practically be the unified DevTools soon.
  - ivanovb 7y ago
    One reason that I use Firefox DevTools mostly is because in the inspector it shows you what events are attached to a DOM element. It's really helpful for debugging legacy applications. Sure, Chrome has something similar but it's a bit more hidden.
- chabad360 7y ago
  Firefox sure has CSS auto-complete (at least in the inspector).
paulintrognon 7y ago
Do you really think the web developpers that use advanced dev tools can make a real difference in their market share? (real question)
- albertgoeswoof 7y ago
  It happens because applications will stop working on chrome if developers never test on it. The recommendation when a user hits a bug will be to check it in Firefox and slowly Firefox will become the reliable/advanced/working option. It’s happened with IE, Chrome before and will swing back away from Chrome eventually.
  - laumars 7y ago
    IE was stagnant and shit, Chrome isn't. I may not like the Chrome monoculture happening at the moment but that doesn't mean Chrome is the same dumpster fire that was IE. And Google are hardly going to let Chrome stagnate when Chrome is the perfect vehicle to local users into Google's non-free ecosystem (I say "non-free" because you pay with your privacy)
    - wizzwizz4 7y ago
      You don't just pay with your privacy. It's not a one-way street. Google's knowledge about you feeds back to you, as they attempt to manipulate you in the way that best increases the money they receive from their advertisers. But if we want people to stop being locked into Chrome, the best way is to cease to support it. If stuff works in Chrome, that'll be because Chrome supports web standards properly, and not because there's some proprietary random Google standard-they-just-came-up-with that it relies on. (I'm looking at you, <portal>.) Don't contribute code to Chromium; instead, contribute it to a popular fork (like ungoogled-chromium), or a different browser altogether. Until Chromium is a less-centralised project, you're pretty much just giving a competitive edge to Chrome, and hence Google's near-monopoly on the web, without Google having to put in the resources to do it themselves. You're working for Google for nothing.
- realusername 7y ago

devit 7y ago

Why "Download Firefox Nightly for macOS"? Is it not supported on Linux and Windows? Why?

phoe-krk 7y ago
https://developer.mozilla.org/en-US/docs/Mozilla/Projects/WebReplay https://developer.mozilla.org/en-US/docs/Mozilla/Projects/We... > Currently only macOS is supported. As for why - no idea.
- propelol 7y ago
  It's probably because its cheaper, and most web developers are using macOS anyway
  - la_fayette 7y ago
    Have been working in web development for years, also with many coworkers. I don't know anybody with macOS except design people...
    - hellofunk 7y ago
      That’s interesting, since nearly all of the developers I know working full stack are using a mac. Maybe it’s a regional thing.
    - coldtea 7y ago
      Seen any web conference where a crapload of people (including many/most of the speakers) didn't have a MacBook? So, while it might be far less in the general market share, and even web dev share, it's more in the "kind of developer that goes to conferences/presets/etc" share...
  - jeroenhd 7y ago
    Of all developers I know, only 2 prefer macOS (in general). Most people are either on Windows or their favourite flavour of Linux. These are not just web developers though, they're full stack developers; perhaps pure frontend developers are more prone to use Apple products?

Blaiz0r 7y ago

This looks great, it's good to see that Firefox is pushing new dev features, instead of playing catch-up to Chrome. Does Replay work on the Firefox Dev build?

y4mi 7y ago
Seems to be a MacOS only feature.

kevsim 7y ago

The biggest benefit for me (I think) would be if the product/design people I work with could find issues and send their recordings to me. Don't think I'll be able to convince them to switch to FF though.

melling 7y ago
I use Chrome, Safari, and the Firefox Nightly. Not sure why there’s so much dedication to one browser.
- Phenix88be 7y ago
  Because they all eat a lots of RAM...
  - rutierut 7y ago
    This is a good comment, I use FF Dev and Chrome RN, the current project I'm working on is Chrome only. It's nice for context switching (docs, etc in FF, debugging & development in GC) but I was not able to do this (1y ago) on my 2013 MB Pro, it was simply to slow.
    - cm-t 7y ago
      you can right click on a tab in firefox, and switch that tab to this or that context ;)
    - melling 7y ago
      I have a 2013 Mac Book Pro with 16 GB of RAM. They all run fine at the same time. I also have Xcode and several other apps open. Don’t skimp on RAM. My next computer will have 32GB of RAM. It’ll extend the usefulness by years.
lkschubert8 7y ago
That is one benefit of going all in on one of the immutable state management libraries. You can maintain past states and on a bug report attach the whole history to be able to play through it.

bdibs 7y ago

Looks potentially really useful, but is it normal for them to create a whole site just for one new feature?

mackrevinack 7y ago
vivaldi put a ton of effort into presenting each update, fancy graphics etc, but yea creating a unique domain for a feature is pretty strange alright
archielc 7y ago
If it is a killer feature, and that's a marketing move - why not. Looks like that Firefox been working hard lately to change trends in browsers' market share.

saimiam 7y ago

This didn't work for me. 1. I installed the nightly build as told. 2. Open nightly build 3. Went to the "Save Recording" option 4. The first two times, I got a [javascript error] saying I could not record. 5. The remaining couple of times - after I open a "New Recording Tab", whatever that is - I didn't see the javascript error but the website whose clickthru I wanted to record using this tool didn't even load in that new recording tab. Just this morning I recorded a clickthru like caveman using Quicktime. Can't wait for FF to iron out the kinks in this feature.

tinus_hn 7y ago
If you’re on Windows, try the built-in Steps Recorder (formerly known as Problem Steps Recorder)
- saimiam 7y ago
  Mac.
jasonlaster11 7y ago
Hmm, join us in http://devtools-html.slack.com/ http://devtools-html.slack.com/ and we'd be happy to help you debug it. If the tab crashed, you can get the report in about:crashes
- nikivi 7y ago
  What do I do if I don't have mozilla or chromium email?
- dependenttypes 7y ago
  Is this an official thing from mozilla? If so it is extremely disappointing that they promote slack.
- jensv 7y ago
  If you have an @mozilla.com or @chromium.org email address, you can create a Slack account. If not it seems like you might be out of luck.

mimischi 7y ago

So in its scope this somewhat similar to Cypress.io? https://www.cypress.io/ https://www.cypress.io/

inglor 7y ago
I don't use Cypress anymore as it didn't work for me but doesn't look like it. This is for debugging rather than testing. Also the timeline in Cypress didn't actually work too well for us.

inglor 7y ago

Is there any way to make this work in automation? This could really help with debugging failed e2e firefox tests.

inglor 7y ago

We actually have something similar for this for tests at Testim (https://testim.io https://testim.io) but only for tests with screenshots and state. Would people be interested in us open sourcing that part for regular debugging? I have considered it but I didn't think people would be interested in using this in a non-test case.

brna 7y ago

No Linux support :(

kreetx 7y ago
Not Linux support yet I hope :)

ga-vu 7y ago

For those interested into how this works, look into Time-Travel Debugging and the WebReplay API

inglor 7y ago

This is a pretty nice comment from the source that explains how it works: https://github.com/mozilla/gecko-dev/blob/11d9c7b7fa82fdfb8ac2a8f0864e9d8d5fe2b926/mfbt/RecordReplay.h#L32-L73 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: intra-thread and inter-thread. // Intra-thread non-deterministic behaviors are non-deterministic even in the // absence of actions by other threads, and inter-thread non-deterministic // behaviors are those affected by interleaving execution with other threads. ```

cocochanel 7y ago
What is non-determinism in the browser?
- jstummbillig 7y ago
  Inputs that are either random or subject to change (api responses, user prompts i.e.)
- correct_horse 7y ago
  Based on the grandparent, it sounds like race-conditions and random number generation fit the bill.
- gitgud 7y ago
  My guess is that "optimisations" (shortcuts) in calculating the final layout, mean that the final layout is not entirely deterministic. It probably varies slightly, due to the entangled nest of dependencies that is responsive HTML rendering...
- janpot 7y ago
  I don't know but if I had to guess: order of responses coming in from the server, interleaved with timer events and user events.
- 7y ago

sandGorgon 7y ago

is this like Postman ?

lovasoa 7y ago
No it is not. It is a browser feature that allows rewinding to a previous state of a webpage. There is much more to that than recording and replaying HTTP requests.

Shaaaaaaare 7y ago

Looks interesting but too bad it only supports overpriced macs making it useless

aphroz 7y ago

While Microsoft is making great effort towards opening, it is sad to see Firefox develop a feature working on Mac OS only. This is terrible because you might argue that this is the same as a feature working on Windows only, but Windows can run on different hardware manufacturer. This is like a double closing. I am on Linux and I will uninstall Firefox as a repercussion hoping it will have an impact. Too bad for the last hope for a chrome alternative.

Aeolun 7y ago
Don’t you think that’s a bit of an overreaction? Maybe it cannot work on anything but OSX?
- aphroz 7y ago
  Yes it is an overreaction. Whenever I see something working on Mac OS only I can't help myself but think that something went wrong in IT since 2000.
senko 7y ago
> Firefox develop a feature working on Mac OS only. Looks to me like this is an experimental feature in Nightly. If it's highly system-dependent I can't blame them for testing the feedback as early as possible, before other systems are supported. Question for Mozilla people here, if anyone sees it - is there a plan to bring this feature across all systems in time for regular Firefox release?
- IainIreland 7y ago
  Last I heard, WebReplay was not on an official roadmap (in the sense that we do not yet have a target date for shipping it in release). That said, I'm pretty sure that the macOS-only restriction is just because that's what the primary developer is using, and it's a higher priority to get the system-independent parts working first. If/when WebReplay is ready to ship, I can't imagine a world where support isn't eventually added for Windows/Linux (although it could be a phased rollout, like WebRender).
7y ago

sdan 7y ago

How is this different from recording in Chrome Web Dev tools? To be clear, I use both Chrome and Firefox for development but just to the surface level, so I'm probably missing the point here.

Vinnl 7y ago
I'm not too familiar with "recording in the Chrome devtools", but this allows you to actually step back as well as forward in the debugger, e.g. for inspecting the value a variable had when code executed before.

ManlyBread 7y ago

This looks pretty good. Are there any other tools like this for different platforms? I'd be especially interested in something like this for the .NET ecosystem.

Vinnl 7y ago
I'm not familiar with .NET, but I think both the Elm devtools and Redux devtools can do something similar, although limited to their own features.

Roark66 7y ago

They should've put this note at the very top of the page: "Mac OS only for now!". What is the point of promoting this to everyone at this stage?

asutekku 7y ago
Why not? A huge portion of developers uses Macs and windows support is coming at some point. Better to get an actual feedback from the developers.
- bflesch 7y ago
  How about linux users?
  - jackcodes 7y ago
    You’ve got to accept the fact they want to collect feedback from other users first and not you.
    - madeofpalk 7y ago
      From some users first, even if that doesn't include you
      - hinkley 7y ago
        No, specifically him. I’ve heard talk. I dunno what he did but he should apologize already.
  - kibwen 7y ago
    Extremely featureful debuggers such as this one tend to require a great deal of code that is hardware-specific, in addition to being OS-specific. I assume MacOS was targeted first because it's the platform with the greatest degree of hardware uniformity. I fully expect Linux support to materialize someday, but with the caveat that I expect it will only (officially) work with the most popular hardware.

aedron 7y ago

I am not primarily a web developer, but I guess I don't really see it. I suppose 'rewind' would mostly be useful for Javascript applications? But in Javascript you can already debug pretty well. It's been a while, but I suppose Javascript debuggers can drop frames, like debugging other languages, so you already have a kind of rewind? Does anyone have a good example use case for this?

Vinnl 7y ago
I'm not quite sure what "drop frames" means in this context, but a use case would be stepping through the debugger, realising that the problem might be in a piece of code that has already executed, and wanting to inspect the value of a variable at that point in time. Or even more mundane: accidentally hitting "Step over" twice in a row.
- aedron 7y ago
  In most debuggers you can drop back up the stack to the code that called the function you are currently in, and thus debug through the function call again. Example: https://stackoverflow.com/questions/2367816/when-using-the-java-debugger-in-intellij-what-does-drop-frame-mean https://stackoverflow.com/questions/2367816/when-using-the-j... "Using the "Drop Frame" functionality you can "fall back" to a previous stack frame, in a sense going back in time."
  - nemetroid 7y ago
    That Stack Overflow answer is poorly worded though, looking at an outer stack frame is really nothing like going back in time. Going back in time in the Firefox Replay sense means reversing execution of the program, e.g. to find the values of variables that have been mutated or gone out of scope.
    - aedron 7y ago
      But that's what drop frame does - it goes back to the state before your current function call, including resetting variables. It does not revert global state (like static variables) but it is essentially like reverting execution 95% of the times I use it.

wruza 7y ago

As a former gnu/linux user, I see no point to have it on a desktop. Gnu is happy to live under c:/MSYS2, and ‘linux’ part was never good at desktop-home hardware anyway. These 1.77% are barely justified as an option, imo.

WanderPanda 7y ago
After struggling with GPU drivers, again, the last couple of days, I could not agree more!
- adam12 7y ago
  I'm assuming these were the closed source proprietary GPU drivers.
- dharmab 7y ago
  I assume this was nvidia. AMD and Intel drivers are finally in a good state but nvidia is as bad as ever.
teddyh 7y ago
> As a former gnu/linux user, I see no point to have it on a desktop. Except, of course, software freedom.
- jhasse 7y ago
  Which Mozilla doesn't care that much about.
akvadrako 7y ago
True, Linux on desktop sucks out of the box. But Windows and Mac suck and it’s not possible to make them good. Personally, I just switched back to Linux after 10 years on Mac. It’s a rough start but now it’s better than Mac and I can continue building the environment I want.
davidy123 7y ago
I don't know what you're talking about. I've used Debian, then Ubuntu for decades. I'm lucky I don't need the few commercial apps that hold people back, so I get the advantages of everything just working, with a good package system that whole time. These days so much is available in the browser or distributed systems, it's even easier. As for 1.77% (excluding ChromeOS and Android based desktop apps, of course), I'm going to guess those people are more significant in terms of software development and user advocacy, on their own and in networks, than the bulk of users. Certainly constantly compromising and taking the enclosed garden path has its drawbacks for the larger community.

tenryuu 7y ago

Regarding Mac OS: looks like, on Windows FF Developer Edition I can access it's UI from creating a boolean in about:config named devtools.recordreplay.enabled A new option in settings will be added to enable a Toolbox Button named "Enable WebReplay", but pressing that button will replace the entire tab content with an about:blank

softwarelimits 7y ago

Can I add a little bit of randomness to this?

Etheryte 7y ago

If this works well, it could eventually be a very big boon for Firefox in the business world. Q&A can now send reproducible bug demos to development. Technical clients can do the same. I wouldn't be surprised if someone built tooling to map these recordings into automated tests either: expect the given recorded workflow to not throw errors. I can't quite remember when I had a bug where a tool like this would've been useful, but I'm sure I would've been (and will be) very thankful for it.

sequoia 7y ago
Oh yeah, wow. Having bug reports come with a replayable & inspectable recording of the user's session would be an absolute game changer. We approximate this now with telemetry tools that allow you to see what the user was doing (sort of), but this would be 100x better.
- tln 7y ago
  I wonder how often the bugs will be so deep that something like LogRocket won't be enough.
jasonlaster11 7y ago
Thanks for the feedback! Our #1 use-case at the moment is bug reports with a recording attached. We think that will really help when it comes to understanding the specifics of a bug when STRs are often not clear.

asaddhamani 7y ago

I would love to give Firefox a shot, but there's one thing I've had issues with, when working with projects using things like webpack, when there's an error, Chrome links me back to the original file and line, I never seem to be able to do this in Firefox. Makes it so much harder to debug things. Am I doing something wrong, or is there a way to fix this?

Vinnl 7y ago
Not sure how long ago you tried, but in one of the recent Firefox versions, they greatly improved the source map support - so it might just be that you should give it another try.
- asaddhamani 7y ago
  I've tried it with the latest versions (as of now), but it doesn't seem to match up with how good Chrome is at it. I've tried both normal Firefox and the developer version. Why is this something Firefox seems to be struggling with? All the Blink based browsers seem to be much better in this regard.

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markdog12 7y ago

Really hope they can get this working with WebGL

Abishek_Muthian 7y ago

Must admit, I've used screen recording during web development for some edge cases; this might address those situations

danShumway 7y ago

My first thought is I'm mildly skeptical that this will end up being granular enough or detailed enough to actually be useful in practice, but if it does, it could be very useful. I'm pretty happy to see Firefox pushing its dev tools in this direction. They've done a really great job with layout and styling tools, but their JS dev tools have lagged behind Chrome's. So even if this particular effort doesn't pan out for some reason, it's still very encouraging. They're not just carbon-copying Chrome, and they're not just sitting back and ignoring the dev tools; they're trying to push them forward in some interesting ways.

_bxg1 7y ago

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.

udfalkso 7y ago
I recently switched back to FF after many years on chrome and find the dev tools to be as good of not better this time around. Curious which tools in particular you find worse? When was the last time you tried?
- _bxg1 7y ago
  You know, as I'm going back and trying to come up with specific points, I'm having a hard time. Partly it's little usability things: - There was one time when an HTTP request was failing and I couldn't figure out why, and in the Network tab Firefox wouldn't show any information about it, even the request that went out (other than the URL), whereas Chrome not only showed the headers, it surfaced that it was a 404. - There's no way to view all source files. You have to go to "Style Editor" for stylesheets and "Debugger" for JS files. I'm not sure how to view the other files that were loaded, outside of the Network tab. - I do enjoy how Chrome's inspector puts the box layout directly above the computed styles, instead of in a separate tab. Those all feel like nitpicks, though. It could just have more to do with me not being used to it. Maybe I haven't given it enough of a chance and should give it another try.
  - bogwog 7y ago
    FF's tools used to be pretty bad compared to Chrome's, and while my main browser has always been FF I always keep Chrome around for development purposes. Lately though I haven't found myself needing to switch over to Chrome for anything devtools related. This new replay feature makes FF even more compelling (once it comes to Linux that is). So if you haven't used FF for development recently, you should definitely give it a try.

smnrchrds 7y ago

Is there a replaying debugger for reverse-engineering dotNet programs?

jrm2k6 7y ago

It might just be me but enabling the option and clicking and the recording button just attempt to reload the page and I get a blank page. Not sure what is supposed to happen.

plorntus 7y ago
Yeah happens to me too, guess either I'm missing an obvious button or it's slightly broken on some machines (which is to be expected).

bogwog 7y ago

Maybe once they figure out how to monetize the data

purple_ducks 7y ago
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 7y ago
  [deleted]
- chinhodado 7y ago
  Don't know why you're downvoted but you're totally right. FF's dev tool is still very far behind Chrome's. IIRC things like websocket inspection aren't even in mainline FF yet. If people want to see many examples of what Chrome's webtool can do and FF can't, just take a look at this page "What's New In DevTools" for each Chrome release. https://developers.google.com/web/updates/2019/10/devtools https://developers.google.com/web/updates/2019/10/devtools
  - dblohm7 7y ago
    > things like websocket inspection aren't even in mainline FF yet Releasing with Firefox 71. https://hacks.mozilla.org/2019/10/firefoxs-new-websocket-inspector/ https://hacks.mozilla.org/2019/10/firefoxs-new-websocket-ins...
    - chinhodado 7y ago
      People have been asking for it for years though. IIRC Chrome has had it since at least 2012.
- 7y ago

deedree 7y ago

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.

saagarjha 7y ago
It’s not going to happen; even if you could run your own browser engine on iOS this requires deep hooks into system calls and Mach messages which isn’t really something that I would see Apple letting you do.

shepardrtc 7y ago

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

shepardrtc 7y ago
Wait, no, its fine. You have to go to the Web Developer tools, then settings, and then turn it on via the check box.

hyt7u 7y ago

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?

mattfrommars 7y ago

This is quiet cool! They did far better job then I would have imagined in doing myself! Ha! [Link to the editor](https://github.com/abdusamed91/realtime-codeeditor https://github.com/abdusamed91/realtime-codeeditor) I implemented it in my real time code editor coursework project where I made use of [Ace Editor](https://ace.c9.io/)'s https://ace.c9.io/)'s CRDT. The time machine slider does the job and looked remarkable when it ran.

8bitsrule 7y ago

Firefox is (mostly) a wonderful, free application. Linux is a wonderful, stable, free desktop. Strange days indeed. Just giving some thanks where it's due.

kyriakos 7y ago

Macos only for now

foobaw 7y ago

I wonder how this is positioned compared to Bird Eats Bug and LogRocket/FullStory

makarov 7y ago
Co-founder of Bird here. Firefox Replay seems to be focusing purely on developers, while we see usage also from PMs, QA and even customer support. So in the end developers can get more data from essentially anyone in the company. Over time we will be adding more tools for developers. It will be interesting to see how Firefox will approach this compared to us.

jasonlaster11 7y ago

Thanks for the feedback! Replay is in the user-research and validation phase and still quite experimental. firefox-replay.com is a work in progress. We're still sorting out the best way to communicate record and replay debugging and the new use cases. We'll share more on @firefoxDevTools when we have something to report.

sfttty 7y ago
Great work! Some insights from FANG. Two more things are necessary to make this a game changer: 1. JS level API to record RNR traces and upload them along with error reports (this will be a new W3C standard). This will be a compelling reason to include Firefox into the automation toolchain and at that point compatibility with Firefox will be mandatory. 2. JS level virtualization or sandboxing. Right now we have the iframe-level sandboxing but this granularity is too coarse because modern web apps have become really big (think of O365). We need a way to fragmentize the JS execution context into smaller docker-like sandboxes and record RNR traces for them. Rationale: big subcomponents should be isolated from each other and have separate traces. As a side effect, this new VM API will enable us to do one cool trick.

ihuman 7y ago

What's going on? I just see a block of text next to a static image. "Replay is an early experiment. We'll let you know on @FirefoxDevTools when it's ready for input."

Kaveren 7y ago
I think they saw that it got a lot of attention on HN and weren't in a stage with the product where they were ready for the corresponding feedback. For anyone who missed what it was, it allows you to derterministically record and replay your browsing for debugging purposes, and you can export these recordings to others.
- ihuman 7y ago
  I just looked it up on the internet archive and saw the old website. I think they should have kept the old one, since the new website has almost no information at all. https://web.archive.org/web/20191128111509/https://firefox-replay.com/ https://web.archive.org/web/20191128111509/https://firefox-r...
  - Narushia 7y ago
    That gives me “The Wayback Machine has not archived that URL.” I also get the same for all the other snapshots, maybe Mozilla applied for a takedown? Edit: I found it on archive.is: http://archive.is/0ei35 http://archive.is/0ei35 Though it seems a bit broken.

meerita 7y ago

I can't see it. > An error occurred when connecting to firefox-replay.com. PR_CONNECT_RESET_ERROR

Karupan 7y ago

This will be an absolute game changer for web development. I am currently working on a really simplified version of this, but as a chrome extension. We deal with a lot of real time data and have been facing some timing issues (network and user input) which is really hard to reproduce. I’m going to give this a shot today!

darshan 7y ago

Mods: the link should perhaps be changed to: https://developer.mozilla.org/en-US/docs/Mozilla/Projects/WebReplay https://developer.mozilla.org/en-US/docs/Mozilla/Projects/We... This currently has 1215 points, and the link is no longer valid. It now just shows an image of Firefox's devtools and the sentence "Replay is an early experiment. We'll let you know on @FirefoxDevTools when it's ready for input." That's not useful, interesting, or informative. The MDN docs seem like an appropriate replacement.

dessant 7y ago
The initial version of the site gave a good overview of Firefox Replay: https://web.archive.org/web/20191128111509/https://firefox-replay.com/ https://web.archive.org/web/20191128111509/https://firefox-r...
- varenc 7y ago
  Note: You can try out Firefox Reply on a macOS in Firefox nightly: https://www.mozilla.org/en-US/firefox/channel/desktop/ https://www.mozilla.org/en-US/firefox/channel/desktop/ Firefox removed the content that tells you this. It's odd that they did that... My guess is that all this attention was a premature launch, and they were hoping to make news with Firefox Replay later. (US Thanksgiving day isn't exactly ideal...)
  - digitarald 7y ago
    Correct on premature launch! Handling all the excitement was fun though while preparing food. There is a lot more work and research needed before rolling this out further.
    - varenc 7y ago
      Awesome job with it! The tech is fascinating. I got it working, somewhat, myself. And thanks for confirming my suspicion! It sure looked like one =)
- 7y ago

swsieber 7y ago

Oh, oh, oh! This is so exciting! I had built a poor mans version of this where I worked with puppeteer for automated tests. It'd basically record the full dim any time it changed, along with console logs, network request metadata, images and css and output it as a test recording. You could then view that and walk through it in an Electron app. This'll blow it out of the water. I hope for e2e testing's sake that linux support comes soon.

empressplay 7y ago

Tangentially, our Apple II emulator [1] has a recording reverse-debugger, should you want to do similar to debug 6502 code... ;) Developers of recent Apple II games have been using it to resolve pesky bugs. [1] https://paleotronic.com/software/microm8/help/web-debugger/ https://paleotronic.com/software/microm8/help/web-debugger/

jv22222 7y ago

I've been working on a slightly related idea - https://speakhq.co https://speakhq.co - I did submit as a Show HN, but didn't get too much traction.

OrgNet 7y ago

Is this a rebranded Firefox Focus?