Nov 2019

Loki is a visual regression tool that works with Storybook, which we mentioned previously in the context of UI dev environments. With a few lines of configuration, Loki can be used to test all UI components. The preferred mode of operation is using Chrome in a Docker container as this avoids one-pixel differences when tests are run in nonidentical environments. Our experience has been that the tests are very stable, but updates to Storybook tend to cause tests to fail with minor differences. It also seems impossible to test components which use position: fixed but you can work around that by wrapping the component with a fixed.