[v4] Troubleshooting issue with Slim

lib/view_component/compiler.rb

@@ -28,6 +28,10 @@ def compile(raise_errors: false, force: false)
         # early exit
         return if compiled? && !force
 
+        # TODO: Needs to reset the template errors in case of Slim "lazy-loaded" (?)
+        reset_template_errors
+        # TODO: Needs to reset the templates in case of Slim "lazy-loaded"
+        reset_templates
         gather_templates
 
         if self.class.__vc_development_mode && @templates.any?(&:requires_compiled_superclass?)
@@ -165,6 +169,14 @@ def template_errors
       end
     end
 
+    def reset_template_errors
+      @_template_errors = nil
+    end
+
+    def reset_templates
+      @templates = nil
+    end
+
     def gather_templates
       @templates ||=
         if @component.__vc_inline_template.present?

lib/view_component/engine.rb

@@ -77,7 +77,12 @@ class Engine < Rails::Engine # :nodoc:
 
     initializer "view_component.eager_load_actions" do
       ActiveSupport.on_load(:after_initialize) do
-        ViewComponent::Base.descendants.each(&:__vc_compile) if Rails.application.config.eager_load
+        # ViewComponent::Base.descendants.each(&:__vc_compile) if Rails.application.config.eager_load
+
+        ViewComponent::Base.descendants.each do |c|
+          # FIXME: trying to not precompile SlimComponent to validate the specs
+          c.__vc_compile if c != SlimComponent
+        end
       end
     end
 

spec/components/slim_component_spec.rb

@@ -0,0 +1,37 @@
+describe SlimComponent do
+
+  before do
+    ViewComponent::CompileCache.invalidate!
+
+    # FIXME: found a better way to "simulate" Slim delay initialization
+    ActionView::Template.unregister_template_handler(:slim)
+    Slim.send(:remove_const, :RailsTemplate) if defined?(Slim::RailsTemplate)
+  end
+
+  context "when slim has not been loaded yet" do
+    it "raise error" do
+      expect { render_preview(:default) }.to raise_error(/Couldn't find a template file or inline render method for SlimComponent/)
+    end
+  end
+
+  context "when slim has been lazy loaded" do
+    before do
+      require "slim"
+
+      # Same stuff as to simulate lazy load: https://github.com/slim-template/slim/blob/main/lib/slim/railtie.rb#L7
+      Slim::RailsTemplate = Temple::Templates::Rails(
+        Slim::Engine,
+        register_as: :slim,
+        generator: Temple::Generators::RailsOutputBuffer,
+        disable_capture: true,
+        streaming: true
+      )
+    end
+
+    it "renders the component" do
+      render_preview(:default)
+
+      expect(page).to have_css "div.slim-div", text: "Hello"
+    end
+  end
+end

test/sandbox/test/components/previews/slim_component_preview.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class SlimComponentPreview < ViewComponent::Preview
+  def default
+    render(SlimComponent.new(message: "Hello"))
+  end
+end