SiteEffect (http://siteeffect.io) is an attempt to build a full blown visual regression testing framework. It enables you to easily detect and understand layout, style and content changes caused by your latest implemented features or any code/contrib/config updates. One major component is an intuitive 'diff-like' UI which lets the user decide if a change is a bug or actually an intended change and therefore a feature. Marked features will be ignored in future test runs, which dramatically reduces the amount of tests that have to be reviewed manually. All of that comes without any project specific effort or costs, it will just work out of the box.

Background:

We all know this, you deploy a new feature, do core or contrib updates or change something in the config. If you are lucky, the project was big enough so you have some automated testing in place (e.g. behat). You will most likely end up doing the usual manual random clicking through pages here and there checking for odd things anyway. If it looks ok you deploy it with a bad feeling in your stomach as you know how wrong this can go. Blocks disappear, layouts break, images are missing, the CSS is off... all that without you noticing.
To fight this you could use one of the visual regression approaches, but all of them are not intuitive, need project specific tests or require a lot of time to manually evaluate the test results. SiteEffect tries to fill this gap.

Session:

In my session I'll present SiteEffect with an extensive demo, give some technical insights and show how it can help with core development to build more stable releases. SiteEffect is still under active development, but it has already been successfully used to test the beta blocker patch #1825952 - Turn on twig autoescape by default. More details on the discussion and the progress of automated testing of core patches with SiteEffect can be found at #2229187.

Resources:

For more information take a look at SiteEffect.io