RSpec::ViewComponent

RSpec::ViewComponent provides contexts that help you write clean one-line specs for your components. This enables you to test that they respond as expected and specify their function without the cruft of boilerplate.

Installation

Add this line to your application's Gemfile, ideally in the test group:

gem 'rspec-viewcomponent'

And then execute:

$ bundle install

Or install it yourself as:

$ gem install rspec-viewcomponent

Usage

Require the gem in your spec_helper.rb:

require 'rspec-viewcomponent'

Then, make the shared context available to component examples:

RSpec.configure do |config|
  config.include RSpec::ViewComponent::Context, type: :component
end

It's suggested that you follow the patterns laid out in spec/viewcomponent/rspec/context_spec.rb when testing your component. Generally, you'll only need to test the rendered component unless you're reliant on methods you call upon it. RSpec::ViewComponent::Context makes this available as the subject of any tests by default, allowing you to write one-line tests with matchers like have_css and be_empty:

describe ExampleComponent do
  let(:args) { ['red'] }
  let(:content) { ->(_view_context = nil) { 'Hello World' } }

  describe 'rendered component' do
    it { is_expected.to have_css('p.red', text: 'Hello World') }

    context 'with nil content' do
      let(:content) { ->(view_context = nil) {} }

      it { is_expected.to be_empty }
    end
  end
end

As you can see there, the context also makes use of two variables defined with let:

  • args, passed to the component upon initialize, e.g. 'red' in the case of ExampleComponent.new('red'). kwargs is also available for keyword arguments.
  • content, passed to the component in a block when it's rendered, e.g. ExampleComponent.new.with_content('Hello World') or
  <%= render ExampleComponent do %>
    Hello World
  <% end %>

component_instance is also available, should you wish to test against the component instance itself.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake spec to run the tests.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/viewcomponent/rspec-viewcomponent. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the code of conduct.

License

The gem is available as open source under the terms of the MIT License.

Code of Conduct

Everyone interacting in the RSpec::ViewComponent project's codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.