Missing partial in tests

[cpjmcquillan]

Thought I'd open a quick discussion in case this is a known issue, something obvious, or indeed intended behaviour.

I should get time to look into it in more detail in the next week or so, and I'll create a small repo that reproduces the issue.

I have a component that needs to render some partials (and these partials render some partials too). It's a whole journey of refactoring, but I wan't to make it as straightforward and pain free as possible, so these partials are staying unchanged.

For example:

# app/components/reports/test.rb

module Reports
  class Test < ViewComponent::Base
    def initialize(report_object:)
      @report_object = report_object
    end
  end
end

<% # app/components/reports/test.html.erb %>

<h1>Report title</h1>

<%= render "report_details" %>

<% # app/views/providers/_report_details.html.erb %>

<p>Some content here</p>

<%= render "other_details" %>

<% # app/views/providers/_other_details.html.erb %>

<p>Some more content</p>

The component renders perfectly fine in development, but in tests we get the below error when trying to render the component.

ActionView::Template::Error:
  Missing partial application/_other_details with ...

Updating the paths to be explicit (i.e <%= render "providers/other_details" %>) resolves the issue, but I don't want to change every partial reference right now (there are lots).

I figured this might be to do with autoloading, or where render looks for partials.

Is there a way to get tests to behave the same as development/production and find the partials?

[boardfish]

Just out of curiosity, does using helpers.render change anything here? To be totally honest I'm not 100% sure it's even possible, but my thinking is that perhaps helpers might lean on the view context in which the component is being rendered, rather than the component's own view context, and thus use the right inferred path.

[joelhawksley]

Hmm, that's an interesting solution. I feel like anything that works in app/views should work in your components, so that's not ideal. I'd prefer to fix this in the framework.

[gap777]

Agreed-- I just don't know your framework well enough to know where / how you want to approach it. The problem only manifested during test for us.

[joelhawksley]

Fair enough, that's why a failing test is a good starting point! Mind opening a PR with one?

[gap777]

Thanks for the encouragement to contribute.
I've thought about such a test... which gets to me thinking about how to make the failure in your repo and test setup. Our rails project is a modular monolith built on top of https://github.com/rubyatscale/packs-rails. We have many view directories, none of which live in the typical location of app/views/. This gem is modifying Rails autoloading to recognize things like packs/pack1/app/views as a view directory. packs/pack1/app/views/shared/_some_partial.html.erb is found when render 'some_partial' is encountered during the app execution. My suspicion is that the "issue" lies here.

If I'm correct, in order to setup a test environment, I'd have to modify your sandbox to use packs. And I don't think either one of us want to do that.

I think we may need to proceed on this with a thought experiment, driving some smaller manual explorations, which will reveal the correct (and small) test to write (and test env to setup).

What about the view_component preview environment deviates from normal Rails view loading logic?

[joelhawksley]

If I'm correct, in order to setup a test environment, I'd have to modify your sandbox to use packs. And I don't think either one of us want to do that.

I wouldn't mind that, actually. We use packs internally so if anything this would help bolster our usage of ViewComponent too.