Cells VS contracts.ruby

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.

I had written a code contracts library for Ruby about 10 years ago [1]. I stopped working on it, mainly because it only provided runtime type checking, and I wanted static type checking. Nowadays my main language is typescript. I miss ruby, but can't give up the static typing that typescript provides. I really wish Ruby had a type system with the same level of support. VSCode has phenomenal TS support, and there's a community adding types to projects [2]. This is something I'd like for Ruby also.

> An integral part of this informality is relying on Matz’s taste and intuition for everything that affects the language’s core.

I think a more defined process would mean a better future for Ruby and Ruby developers.

- [1] https://github.com/egonschiele/contracts.ruby

- [2] https://github.com/DefinitelyTyped/DefinitelyTyped

Contracts gem can be a nice middle-ground. It has a fairly readably syntax and only checks method inputs and outputs at runtime. We use it to annotate important core methods, while leaving the rest type-free.

For example contracts gem needs to have a separate version/branch for ruby 3.x due to the breaking change above

This gives me access to input values as long as I defined them via attr_reader. Oh what's the Contract XXX above attr_reader? They are from contracts.ruby and completely optional and won't be explained in this post. You can safely ignore those and maybe study that gem later.