Rails 7 autoloading issue

[woller]

When using both minitest-spec-rails and view_component in the same project, tests would blow up with the following stack trace:

Traceback (most recent call last):
        58: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/rake-13.0.6/lib/rake/rake_test_loader.rb:6:in `<main>'
        57: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/rake-13.0.6/lib/rake/rake_test_loader.rb:6:in `select'
        56: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/rake-13.0.6/lib/rake/rake_test_loader.rb:21:in `block in <main>'
        55: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/rake-13.0.6/lib/rake/rake_test_loader.rb:21:in `require'
        54: from /Users/woller/code/traels/open_source/minitest-spec-rails/test/cases/action_controller_test.rb:1:in `<top (required)>'
        53: from /Users/woller/code/traels/open_source/minitest-spec-rails/test/cases/action_controller_test.rb:1:in `require'
        52: from /Users/woller/code/traels/open_source/minitest-spec-rails/test/test_helper.rb:1:in `<top (required)>'
        51: from /Users/woller/code/traels/open_source/minitest-spec-rails/test/test_helper.rb:1:in `require'
        50: from /Users/woller/code/traels/open_source/minitest-spec-rails/test/dummy_app/init.rb:42:in `<top (required)>'
        49: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/railtie.rb:207:in `method_missing'
        48: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/railtie.rb:207:in `public_send'
        47: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/application.rb:369:in `initialize!'
        46: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/initializable.rb:60:in `run_initializers'
        45: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:205:in `tsort_each'
        44: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:226:in `tsort_each'
        43: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:347:in `each_strongly_connected_component'
        42: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:347:in `call'
        41: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:347:in `each'
        40: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:349:in `block in each_strongly_connected_component'
        39: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:431:in `each_strongly_connected_component_from'
        38: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:350:in `block (2 levels) in each_strongly_connected_component'
        37: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/2.7.0/tsort.rb:228:in `block in tsort_each'
        36: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/initializable.rb:61:in `block in run_initializers'
        35: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/initializable.rb:32:in `run'
        34: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/railties-7.0.0.alpha2/lib/rails/initializable.rb:32:in `instance_exec'
        33: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/view_component-2.42.0/lib/view_component/engine.rb:21:in `block in <class:Engine>'
        32: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        31: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        30: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/view_component-2.42.0/lib/view_component/base.rb:14:in `<top (required)>'
        29: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/view_component-2.42.0/lib/view_component/base.rb:15:in `<module:ViewComponent>'
        28: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        27: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        26: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionview-7.0.0.alpha2/lib/action_view/base.rb:12:in `<top (required)>'
        25: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionview-7.0.0.alpha2/lib/action_view/base.rb:141:in `<module:ActionView>'
        24: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionview-7.0.0.alpha2/lib/action_view/base.rb:279:in `<class:Base>'
        23: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:51:in `run_load_hooks'
        22: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:51:in `each'
        21: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:52:in `block in run_load_hooks'
        20: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:66:in `execute_hook'
        19: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:61:in `with_execution_control'
        18: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:71:in `block in execute_hook'
        17: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/lazy_load_hooks.rb:71:in `class_eval'
        16: from /Users/woller/code/traels/open_source/minitest-spec-rails/lib/minitest-spec-rails/railtie.rb:25:in `block (2 levels) in <class:Railtie>'
        15: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        14: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        13: from /Users/woller/code/traels/open_source/minitest-spec-rails/lib/minitest-spec-rails/init/action_view.rb:22:in `<top (required)>'
        12: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        11: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/zeitwerk-2.5.1/lib/zeitwerk/kernel.rb:35:in `require'
        10: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionview-7.0.0.alpha2/lib/action_view/test_case.rb:10:in `<top (required)>'
         9: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionview-7.0.0.alpha2/lib/action_view/test_case.rb:12:in `<module:ActionView>'
         8: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionview-7.0.0.alpha2/lib/action_view/test_case.rb:13:in `<class:TestCase>'
         7: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionpack-7.0.0.alpha2/lib/action_controller/railties/helpers.rb:19:in `inherited'
         6: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionpack-7.0.0.alpha2/lib/abstract_controller/helpers.rb:148:in `helper'
         5: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionpack-7.0.0.alpha2/lib/action_controller/metal/helpers.rb:104:in `modules_for_helpers'
         4: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionpack-7.0.0.alpha2/lib/abstract_controller/helpers.rb:170:in `modules_for_helpers'
         3: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionpack-7.0.0.alpha2/lib/abstract_controller/helpers.rb:170:in `map!'
         2: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/actionpack-7.0.0.alpha2/lib/abstract_controller/helpers.rb:177:in `block in modules_for_helpers'
         1: from /Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/core_ext/string/inflections.rb:74:in `constantize'
/Users/woller/.rbenv/versions/2.7.3/lib/ruby/gems/2.7.0/gems/activesupport-7.0.0.alpha2/lib/active_support/inflector/methods.rb:280:in `constantize': uninitialized constant ApplicationHelper (NameError)

After some investigation I traced the problem to the way MiniTestSpecRails::Init::ActionViewBehavior is included on line 22 of lib/minitest-spec-rails/init/action_view.rb. Rails 7 drops support for the classic autoloader and now only supports zeitwerk. Wrapping the include statement in a to prepare block, solves the issue:

module MiniTestSpecRails
  module Init
    module ActionViewBehavior
      extend ActiveSupport::Concern

      included do
        class_attribute :_helper_class
        register_spec_type(/(Helper|View)( ?Test)?\z/, self)
        register_spec_type(self) { |desc| desc.is_a?(Class) && desc < self }
        extend Descriptions
      end

      module Descriptions
        def described_class
          determine_default_helper_class(name)
        end
      end
    end
  end
end

Rails.application.reloader.to_prepare do
  ActionView::TestCase.send :include, MiniTestSpecRails::Init::ActionViewBehavior
end

For more details, see: https://edgeguides.rubyonrails.org/autoloading_and_reloading_constants.html#use-case-1-during-boot-load-reloadable-code

The same pattern for including code is used in all the other parts of the railtie and should probably be patched as well, but I have not experienced any other issues with this gem and Rails 7

This issue seems similar to #109 and I suspect, that this might solve that issue as well.

[metaskills]

Thanks! I just pushed v6.1.0 with this change.