Happo.io is a straight up life-saver. It is the only screenshot testing tool I’ve ever used, so I would not be sophisticated enough to compare it to alternatives, if there are any, but the essential idea is that you push code, and it goes off and renders all the components in your PR, comparing it with the version on master.

This means if you edit a component like <Input /> it will show you the impact on components that use Input, including the Search Bar you accidentally modified. It. Is. Fabulous.

How many times did you think your change was contained only to discover that ten other teams started using what you built, and your change breaks three of the ten? Without Happo, you might not know.

Until lately, the only downside with Happo was that our React Storybook variations (the input to the screenshot testing process) did not always reflect reliable data adequately. Now that Storybook is leveraging API data, we can feel much more confident. Plus, as our demo explores, it is automatic. If you add a field to the query and then the component, Happo will automatically post the diff to your PR, letting the engineers, designers, and product managers sitting next to you see the visual consequences of the change you have made.