Visual Regression Testing
Charlie Owen@sonniesedge
Visual Regression Testing
Testing things because things getting messy makes me twitchy and people don’t like it when I get twitchy.
Robert K. Merton, American sociologist
“The law of unintended consequences”
Web developer
“Oh fuck, I broke the build”
<p>Hello!</p>
p { font-size: 2em;}
Take initial screenshot
<p>Hello!</p>
p { font-size: 4em;}
Take second screenshot
Image diffing Image 1
Image diffing Image 2
Image diffing Differences in red
.btn-lg { padding-right: 20px;}
compare image1.png image2.png -compose src diff.png
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PhantomCSSWraithGrunt-photoboxNeedle
SLIDE REMOVED DUE TO VIDEO SIZE
image of previous diff
Stephen Hay
“We’re not designing pages, we’re designing systems of components.”
Component libraries