Ask HN: What do you recommend for Visual Regression Testing in 2021?

I have a legacy ecommerce codebase that is primarily wordpress / php that has many plugins that want to be updated regularly.

While I'm triaging bugs and working toward a sane deployment I need to be able to more safely test that plugin updates are not breaking the site.

Ideally, I'd like to avoid anchoring the company to a paid service, and instead invest in building infrastructure if feasible.

I have the flexibility of running any testing tools I want, (I can set up a VPS and run anything against staging and production.)

I prefer / am best at Python and prefer containerization where possible.

I'm very experienced with github actions and ultimately want visual regression to be a part of CI/CD.

There hasn't been a post about this in some time, the active FOSS options I'm seeing include:

- BackstopJS

- Cypress

Active commercial solutions include:

- Applitude

- Diffy

- Screenster

Any feedback on picking a headless browser or really the entire technology stack for visual testing would be appreciated.