Testing ViewComponents with Devise

[jordanbrock]

Howdy all,

TL;DR:
Unable to test a view component that relies on a devise helper method

Just starting out on converting an existing site to use ViewComponents, and I've run into a little snag. The site has a news feed, that is essentially an array of a number of different objects (new products, new customers, comments etc).

I have a ViewComponent that uses :with_collection_parameter that iterates the items, and determines which partial to render, based on the object type.

The component view file then renders that partial

= render(partial: @partial_path, locals: { item: @item })

It's working fine in development, but when I try and write a test to make sure the correct partials are being rendered I'm getting an error. The partial makes a call to "current_user" which is a method provided by Devise. Normally in Controller tests, you can include Devise::TestHelpers and it will inject appropriate code into the @request.env to help the test run.

However, when I put the following in my test_helper.rb

class ViewComponent::TestCase
  include Devise::TestHelpers
  # or include Devise::Test::ControllerHelpers
end

I get the following error:

NoMethodError: undefined method `env' for nil:NilClass

which is devise attempting to do the following:

def setup_controller_for_warden #:nodoc:
  @request.env['action_controller.instance'] = @controller
end

Does anyone have any suggestion on how to get the tests to run?

[joelhawksley]

@jordanbrock thanks for taking the time to file this issue! Compatibility with common frameworks like Devise is important.

I see a couple possible paths to take here:

1) Pass in the user!

If you were to pass current_user into the component explicitly, you wouldn't need to rely on the global Devise accessor at all.

2) Create your own test helper

This is what we do in the GitHub codebase:

module GitHub
  module ComponentTestHelpers
    include ViewComponent::TestHelpers

    def as(user)
      controller.send(:current_user=, user)
    end
  end
end

Which allows us to write tests like:

as(@user)
render_inline(Dashboard::BannerComponent.new)

3) Update ViewComponent to be compatible with Devise!

It'd be pretty cool to see us support the use case you describe out of the box. We already have some test helpers included with the library: https://github.com/github/view_component/blob/master/lib/view_component/test_helpers.rb, perhaps we could make changes that would support Devise?

[jordanbrock]

Thanks for the reply @joelhawksley. I had already refactored the partial that was calling current_user so point 1) solved the immediate problem.

I'll have a look at point 3) and see if it's something I can have a crack at.

[equivalent]

22024-08 I'm using this to access Devise current_user in ViewComponent RSpec component tests/specs

module MyappViewComponentTestHelper
  include ViewComponent::TestHelpers

  def sign_in(user)
    allow(vc_test_controller).to receive(:current_user).and_return(user)
  end
end

# spec/rails_helper
RSpec.configure do |config|
  # ..
  config.include MyappViewComponentTestHelper, type: :component
  # ..
end

# spec/components/whatever_component.rb
describe WhateverComponent, type: :component do
#...
it do 
  sign_in(user)
  render_inline(WhateverComponent.new)
end
end

reference https://github.com/ViewComponent/view_component/blob/main/lib/view_component/test_helpers.rb

note controller mentioned in prev post above is nowvc_test_controller

---

bonus you are able to modify controller params like this:

module MyappViewComponentTestHelper
  # ...
  def switch_client_context(client)
     vc_test_controller.params[:current_client] = client.id
  end
end

[Floppy]

Thank you, this worked for me!