Capybara VS Cells

Cuba takes help from a lot of other technologies to bring the best of everything. For example, the responses in Cuba are the optimized version of the Rack responses. The templates are integrated via Tilt and testing via Cutest and Capybara.

I am going to use a browser based testing tool called Playwright (But you could use Capybara, or Selenium WebDriver etc.).

Even as a much smaller team, building Heii On-Call [0] as a lightweight alerting/monitoring/on-call rotations SaaS based on Ruby on Rails has basically been a pleasure!

And as the article highlights, perhaps the key reason for smooth deployments and upgrades is that the CI testing story is so, so good: RSpec [1] plus Capybara [2] for us. That means we have decently extensive tests of just about all behavior. The few small Rails and Ruby upgrades we've done have gone quite smoothly and confidently, with usually just a few non-Rails gem dependencies needing to be manually updated as well.

The "microservices" story is where we've pulled in the Crystal programming language [3] to great effect. After dabbling with Go and Rust, we've found that Crystal is truly a breath of fresh air. Crystal powers the parts of Heii On-Call that need to be fast and low-RAM, specifically the inbound API https://api.heiioncall.com/ and the outbound HTTP(S) prober background processes. I've ported some shared utility classes from Ruby to Crystal almost completely by just copy-and-pasting ___.rb to ___.cr; porting the tests for those classes was far more onerous than porting the class code itself. (Perhaps another point of evidence toward the superiority of RoR's testing story...)

The front-end story is nice but just a bit weaker. Using Hotwire / Turbo successfully, but I have an open PR to fix a fairly obvious stale cache bug in Turbo [4] that has been sitting unloved for nearly a month, despite other users reporting the same issue. I'm hopeful that it will get merged in the next release, but definitely less active than the backend side.

For me, the key conclusion is that the excellent Ruby on Rails testing story is what enables everything to go a lot more smoothly and have such a strong foundation. I'd be curious if any GitHubbers can talk more about whether they too are using Rspec+Capybara or something else? Are there internal guidelines for test coverage?

[0] https://heiioncall.com/

[1] https://rspec.info/

[2] https://github.com/teamcapybara/capybara

[3] https://crystal-lang.org/

[4] https://github.com/hotwired/turbo/pull/895

Engineering at Aha! focuses on using and improving the Capybara test framework. We have added many helpers and additional functionality to make working with Capybara easy. Testing at mobile widths is another chance to improve our testing tooling. Here is the incremental approach that we used to add mobile testing helpers.

Since the Capybara library drives the underlying tests, Minitest also has the same syntax.

We can write component tests with any language or framework, but the most popular ones are probably Cucumber and Capybara.

The nice thing about partial templates is that templates are unit-testable with View specs (or similarly in Minitest) and the rendered output can even be verified using Capybara matchers.

To piggyback: This would be a type of browser test, so you would want to use something like Cypress (https://github.com/testdouble/cypress-rails) or Capybara (https://github.com/teamcapybara/capybara). RSpec has a good integration with Capybara. Cypress is JS-based so it will require some additional config.

When you write a system test (or, as we prefer, a system spec) with Ruby on Rails, you're exercising the whole stack from the point of view of the user. So, naturally, you have to do things like make sure that certain elements are on the page and work as you expect when you click on then, type in them, and drag them around. Capybara works exceedingly well for this, giving you a lovely API for querying HTML.

It can be used with Ruby on Rails or other frameworks because I implemented with trailblazer/cells.

I agree, though cells does still have a larger following.

Better official documentation for cells: https://trailblazer.to/2.1/docs/cells.html

So what about the world outside Rails defaults? There are quite a few independent projects trying to help build components in the Rails view layer, among the more famous being Draper (utilizing the decorators pattern) or Cells (full-featured components in views). In the end, we decided to take a deeper look into a relatively new one – the ViewComponent framework.

GitHub has recently posted an article about view_component: https://github.blog/2020-12-15-encapsulating-ruby-on-rails-views/ Before it gets too popular I think I should share my experience with cells So that developers can have another chance to re-think and pick what to use for "encapsulated view components".

This, combined with the fact that we are using cells gem for some view components, resulted in another couple of hours of hunting for the problem (it takes some time to debug what exactly and how exactly changed in Rails internals) and then fixing this problem. At this moment, I already spent over 8 hours debugging Rails internals, different gem internals, fixing application, fixing tests, screaming internally.