Add tests to validate CSS module handling in pack generator (#1775)

Author: AbanoubGhadban

spec/dummy/spec/packs_generator_spec.rb

@@ -438,6 +438,7 @@ def create_new_component(name)
     context "when component with CSS module" do
       let(:component_name) { "ComponentWithCSSModule" }
       let(:component_pack) { "#{generated_directory}/#{component_name}.js" }
+      let(:css_module_pack_glob_pattern) { "#{generated_directory}/#{component_name}.module*" }
 
       before do
         stub_packer_source_path(component_name: component_name,
@@ -469,6 +470,15 @@ def create_new_component(name)
         expect { eval(sanitized_content) }.not_to raise_error
         # rubocop:enable Security/Eval
       end
+
+      it "does not generate a pack for a CSS module file" do
+        expect(Dir.glob(css_module_pack_glob_pattern)).to be_empty
+      end
+
+      it "only generates the js pack" do
+        generated_files = Dir.entries(generated_directory).reject { |f| f.start_with?(".") }
+        expect(generated_files).to eq([File.basename(component_pack)])
+      end
     end
 
     def generated_server_bundle_file_path