Screenshot Tests about playground-elements

[e111077]

This came into my twitter feed yesterday

https://www.npmjs.com/package/@web/test-runner-visual-regression

[justinfagnani]

The Workbox team pointed me to this for an example: https://github.com/GoogleChromeLabs/sw-appcache-behavior/blob/master/tests/test-suite.js

[43081j]

Keep in mind they use pixelmatch internally, which can have trouble with font smoothing differences across different OSes. Most libraries will have the same problem, looks-same tries to handle this by some clever algorithms but still trips up on it sometimes.

Just something to take into account I guess. The one true solution is to always generate them in CI so they are consistent i think, knowing that people who clone the repo are likely to get slightly different screenshots.