Add test for multiple template variants

Author: fsateler

lib/view_component/compiler.rb

@@ -129,14 +129,14 @@ def template_errors
 
           invalid_templates =
             templates
-              .group_by { |template| template[:variant] }
-              .map { |variant, grouped| variant if grouped.length > 1 }
+              .group_by { |template| template[:variant].present? ? "#{template[:base_name]}+#{template[:variant]}" : template[:base_name] }
+              .map { |template, grouped| template if grouped.length > 1 }
               .compact
               .sort
 
           unless invalid_templates.empty?
             errors <<
-              "More than one template found for #{"variant".pluralize(invalid_templates.count)} " \
+              "More than one template+variant found for #{"template".pluralize(invalid_templates.count)} " \
               "#{invalid_templates.map { |v| "'#{v}'" }.to_sentence} in #{component_class}. " \
               "There can only be one template file per variant."
           end

test/sandbox/app/components/sub_templates_component/list.html+ordered.erb

@@ -0,0 +1,6 @@
+<%# locals: (number:) %>
+<ol data-number="<%= number %>">
+  <% @items.each do |item| %>
+    <li><%= item %></li>
+  <% end %>
+</ol>

test/sandbox/app/components/sub_templates_component/sub_templates_component.html+ordered.erb

@@ -0,0 +1,4 @@
+<div class="container">
+  <%= render_summary_template string: string %>
+  <%= render_ordered_list_template number: number %>
+</div>

test/sandbox/test/rendering_test.rb

@@ -544,7 +544,10 @@ def test_raises_error_when_more_than_one_sidecar_template_is_present
         render_inline(TooManySidecarFilesComponent.new)
       end
 
-    assert_includes error.message, "More than one template found for TooManySidecarFilesComponent."
+    assert_includes(
+      error.message,
+      "More than one template+variant found for template 'too_many_sidecar_files_component' in TooManySidecarFilesComponent."
+    )
   end
 
   def test_raises_error_when_more_than_one_sidecar_template_for_a_variant_is_present
@@ -555,7 +558,9 @@ def test_raises_error_when_more_than_one_sidecar_template_for_a_variant_is_prese
 
     assert_includes(
       error.message,
-      "More than one template found for variants 'test' and 'testing' in TooManySidecarFilesForVariantComponent"
+      "More than one template+variant found for templates " \
+      "'too_many_sidecar_files_for_variant_component+test' and 'too_many_sidecar_files_for_variant_component+testing' " \
+      "in TooManySidecarFilesForVariantComponent"
     )
   end
 
@@ -594,7 +599,7 @@ def test_raise_error_when_template_file_and_sidecar_directory_template_exist
 
     assert_includes(
       error.message,
-      "More than one template found for TemplateAndSidecarDirectoryTemplateComponent."
+      "More than one template+variant found for template 'template_and_sidecar_directory_template_component' in TemplateAndSidecarDirectoryTemplateComponent."
     )
   end