feat: Simpler way to test Ruby components?

[harrisj]

Summary

It would be useful to be able to run Minitest against Ruby components directly (perhaps in the pre-render hook), especially if it could also still use Zeitwerk loading

Motivation

I am migrating some partials to Ruby components and I appreciate the ability to code logic in the class and methods. For instance I have a date display label that has a few formatting parameters.

It's not clear how I could write tests for this. There is a mini testing framework but it's for generated pages. I could write tests for the components but it's after site generation is over and requires a lot of deft require statements. Having a way to test them that feels more natural would be great

Guide-level explanation

Once you have written your component, you should also create tests for it! Some components may have multiple configuration options which alter behavior and be presented with different types of data.

Component tests can be written and placed in directory X. They can use Zeitwerk includes (in the same way components do) and these tests are run before site rendering to ensure they pass.

Reference-level explanation

I'm not sure of the best way to implement this.

Drawbacks

It might add complexity and not be used by many people. Maybe components should be tested through something like Storybook?

Unresolved Questions

None that I can think of. This can use data loaded into the system (or Sequel), but it may be necessary to mock or stub input arguments sometimes.

[jaredcwhite]

This all makes good sense, and I suspect it's possible to test a component already but we just don't have that documented anywhere. For example, using the new render class method of TemplateView:

Bridgetown::TemplateView.render(MyComponent.new(some_arg: 123)) # outputs a string you could test against

Zeitwerk should just work and you shouldn't need any require statements. Not sure if that's a documentation issue or an actual bug…maybe you could supply an example that's failing for you?

[harrisj]

Probably my mistake, but I have a component defined in _components/atoms/data_range.rb but it's not finding my component

# frozen_string_literal: true

require_relative '../minitest_helper'

class TestDateRange < Bridgetown::Test
  def test_default_rendering
    start_date = Date.new(2025, 10, 1)
    end_date = Date.new(2025, 10, 7)
    rendered = Bridgetown::TemplateView.render(::Atoms::DateRange.new(start_date: start_date, end_date: end_date))

    assert_equal '<span class="md:text-nowrap my-date"></span>', rendered
  end
end

If I require_relative the component, I get an issue in the render

NoMethodError: undefined method 'collections' for nil
    /Users/harrisj/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/bridgetown-core-2.1.2/lib/bridgetown-core/model/base.rb:45:in 'block in Bridgetown::Model::Base.build'
    /Users/harrisj/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/bridgetown-core-2.1.2/lib/bridgetown-core/model/builder_origin.rb:29:in 'Bridgetown::Model::BuilderOrigin#read'
    /Users/harrisj/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/bridgetown-core-2.1.2/lib/bridgetown-core/model/base.rb:44:in 'Bridgetown::Model::Base.build'
    /Users/harrisj/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/bridgetown-core-2.1.2/lib/bridgetown-core/template_view.rb:55:in 'Bridgetown::TemplateView.virtual_view'
    /Users/harrisj/.rbenv/versions/3.4.2/lib/ruby/gems/3.4.0/gems/bridgetown-core-2.1.2/lib/bridgetown-core/template_view.rb:81:in 'Bridgetown::TemplateView.render'
    test/components/test_date_range.rb:10:in 'TestDateRange#test_default_rendering'

Anyhow, I can dig around. It's probably my mistake somewhere.

[harrisj]

Okay, yes, I can require_relative to find the component (not getting pulled in by Zeitwerk), but then it fails on a call to site.collections. Here is my test code

# frozen_string_literal: true

require_relative '../minitest_helper'
require_relative '../../src/_components/atoms/date_range'

class TestDateRange < Bridgetown::Test
  describe "default date range rendering" do
    subject do
      start_date = Date.new(2025, 10, 1)
      end_date = Date.new(2025, 10, 7)
      component = ::Atoms::DateRange.new(start_date: start_date, end_date: end_date)
    end

    it "is not null" do
      expect(subject).wont_be_nil
    end
  
    it "uses the compact date/year format" do
      rendered = Bridgetown::TemplateView.render(subject).call
      expect(rendered).must_equal '<span class="md:text-nowrap my-date"></span>'
    end
  end
end

I do the call in there to get the rendered HTML out (it's a proc). Is that my mistake? It worked in the console to do that