Visual testing is needed to quickly confirm that a page looks like it should by comparing screenshots taken automatically on that page with reference screenshots previously marked as valid.
- Visual testing software would start (normally as a daily Github Action here) and access this google spreadsheet, which contains URLs and behaviors we would like to test.
- Visual testing software would then visit the URLs and perform the behaviors as specified in the spreadsheet and take screenshots for each test.
- Visual testing software would upload these screenshots to the cloud (normally to Percy.io here but also possible to google drive here) where a human can review them and judge if the change was intended or not.
- Percy.io would report to slack channels if it detects visual changes.