[HN Gopher] Show HN: Lost Pixel - open-source visual regression ...
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       Show HN: Lost Pixel - open-source visual regression testing for
       your frontend
        
       Author : divdev_
       Score  : 77 points
       Date   : 2022-09-19 13:18 UTC (9 hours ago)
        
 (HTM) web link (github.com)
 (TXT) w3m dump (github.com)
        
       | fishtoaster wrote:
       | This is very cool! I've found visual regression testing in CI to
       | be one of the highest-value things I can throw into new, long-
       | lived frontend codebase. I've been relying on Chromatic so far,
       | but I'd definitely try out Lost Pixel next time I'm setting up
       | such a project!
        
         | divdev_ wrote:
         | Visual regression tests rock! Be sure to ping me (@divdev_ on
         | twitter) when you will be doing that - would be very eager to
         | pair with you on this and help you set everything up!
        
       | divdev_ wrote:
       | Hey! My name is Dima, I am from Ukraine and I am the co-founder
       | of Lost Pixel! We built this tool to solve our problems at work
       | and decided to open-source it so more people can build their
       | custom visual regression testing pipelines! If you want to chat
       | about the tool or visual regression testing in general I am super
       | excited to meet like-minded people! Thanks a lot for checking out
       | the product and I hope it will serve you well if you decide to
       | try it out :D
        
         | mattlondon wrote:
         | How do you handle "meaningless" visual changes? E.g. chrome
         | version change introduces super-subtle blending changes to
         | drop-shadows, and suddenly there are huge diffs because the
         | least significant bit of a drop-shadow's grey colour changed.
         | What is your approach to that?
         | 
         | So far all tools I have used like this suffer from "false
         | positives" like this (it's a true positive technically of
         | course, but likely false from an engineering perspective).
        
           | divdev_ wrote:
           | We don't at the moment differentiate, but it is definitely a
           | feature on the roadmap. There are multiple ways to solve this
           | and we are considering quite some of them:
           | 
           | 1. Grayscaling browser before screenshot 2. Using custom
           | diffing engines that enable for ignoring regions like odiff
           | 3. Trying to be smart and analyzing images with machine
           | learning to identify how meaningful the difference is
           | (moonshot but worth exploring)
           | 
           | Our approach to this in general is that if false positive
           | like this happens we can just batch approve all the
           | differences and be ok with that as it was a subtle rendering
           | change not dependent on us or our direct third party
           | dependencies.
        
       | acketon wrote:
       | Hi Dima, this looks really good! I see examples for Storybook and
       | Next.js. Would this work with other technologies and
       | configurations? For instance is there a way to point it at an
       | external dev sandbox to capture full page screenshots of an
       | existing site... say a WordPress site or other CMS? I have a use
       | case where I want to test full page screenshots but need the
       | environment that is hosting a copy of the content/database to
       | test against, not just the components used in the pages.
        
         | divdev_ wrote:
         | hey! Absolutely, Lost Pixel is designed to be able to test
         | anything which can be opened in a browser window. So any
         | technology and configuration should be quite flexible to be
         | tested as long as the host is publicly accessible from your
         | runner of lost-pixel engine. So in your case if you can run
         | your environment somewhere and point lost-pixel there it should
         | work as expected! Feel free to reach out if you need help - we
         | are happy to chat and assist you! Github discussions or
         | @divdev_ or @chriskalmar on twitter are both good ways to reach
         | us!
        
       | kasperg wrote:
       | The open-source angle aside: How does Lost Pixel compare to
       | Chromatic?
       | 
       | It might be nice to add a comparison to your otherwise excellent
       | documentation.
        
         | divdev_ wrote:
         | We are not backed by any VC - just indie hacking that's the
         | greatest prerequisite to comparing ourselves to Chromatic. At
         | the SaaS level we want to bring value to the community by:
         | 
         | 1. allowing visual regression testing integration in any part
         | of your flow(locally for free, paid on the platform) with any
         | need for visual testing(stories, pages, components, cypress,
         | playwright). Chromatic is focused on building upon their
         | fundament - storybook. 2. making it affordable. Everybody
         | agrees to one thing - the prices to visual tests are bonkers
         | when it comes to SaaS. We embraced the fact that people want
         | flexible and cheap as much as they want fast and expensive. We
         | will allow to run actual engine on your premises making our
         | pricing significantly cheaper, we will allow storing images on
         | your side which will again make it ridiculously cheap for you
         | as you won't be paying markup that we otherwise could induce on
         | those things. 3. not being protective of our codebase for core
         | part of the offer. We want community to build the top-notch
         | visual regression testing engine _with_ us to serve _the
         | community_!
         | 
         | Hope it sheds some light into bigger picture, otherwise Chris &
         | I will definitely add the table for comparison with Chromatic &
         | Percy. this is very legit point, thank you!
        
       | kilian wrote:
       | I've set up visreg tests in the past and they were always slow
       | and brittle. This looks really modern and well documented system,
       | congrats to the team! Always running them on GitHub actions will
       | keep the sub pixel issues at a minimum, but do you also have
       | configurable thresholds?
        
         | divdev_ wrote:
         | Hey! Thanks for the nice words, yes we do - thresholds is
         | indispensable part of Lost Pixel, after all we don't want to
         | battle the tests which are 2-3 pixels different, those should
         | pass by default.
        
       | Akcium wrote:
       | I think I have already seen your project on Twitter, remember the
       | nice gif.
       | 
       | Wish you luck with the project.
        
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       (page generated 2022-09-19 23:01 UTC)