Merge branch 'main' into class-translate-missing-keys

Author: joelhawksley

docs/CHANGELOG.md

@@ -14,6 +14,10 @@ nav_order: 6
 
     *Andrii Furmanets*
 
+* Only recompile components when a template or a translation file changed, instead of before every request, when templates aren't cached. Pages render about twice as fast in development.
+
+    *Clément Joubert*
+
 ## 4.16.0
 
 * Fix subclasses defined after their parent renders a collection using the parent's default collection parameter name instead of their own. Fix recompiling a component not refreshing its collection parameter, counter, and iteration detection. Compute that detection when a component compiles, and store the results frozen so they're shareable across Ractors.

lib/view_component/compile_cache.rb

@@ -25,5 +25,14 @@ def invalidate_class!(klass)
     def invalidate!
       cache.clear
     end
+
+    # Invalidates the cache when a template or a translation file is added,
+    # changed, or removed. Changes to Ruby files reload the application instead.
+    def template_watcher(file_watcher)
+      extensions = ActionView::Template::Handlers.extensions.map(&:to_s) + %w[yml yaml]
+      directories = ActiveSupport::Dependencies.autoload_paths.index_with(extensions)
+
+      file_watcher.new([], directories) { invalidate! }
+    end
   end
 end

lib/view_component/engine.rb

@@ -132,9 +132,16 @@ class Engine < Rails::Engine # :nodoc:
         end
       end
 
+      template_watcher = nil
+
       app.executor.to_run :before do
-        CompileCache.invalidate! unless ActionView::Base.cache_template_loading
+        next if ActionView::Base.cache_template_loading
+
+        template_watcher ||= CompileCache.template_watcher(app.config.file_watcher)
+        template_watcher.execute_if_updated
       end
+
+      app.reloader.before_class_unload { CompileCache.invalidate! }
     end
   end
 end

test/sandbox/test/integration_test.rb

@@ -86,6 +86,33 @@ def test_template_changes_are_reflected_on_new_request_when_cache_template_loadi
     end
   end
 
+  def test_components_are_not_recompiled_on_new_request_when_no_template_changed
+    with_new_cache do
+      get "/controller_inline"
+      MyComponent.__vc_compile
+
+      get "/controller_inline"
+      assert_response :success
+      assert MyComponent.__vc_compiled?
+    end
+  end
+
+  def test_components_are_recompiled_on_new_request_when_a_template_is_added
+    new_template = Rails.root.join("app/components/added_template_component.html.erb")
+
+    with_new_cache do
+      get "/controller_inline"
+      MyComponent.__vc_compile
+
+      File.write(new_template, "<div>Added</div>")
+      get "/controller_inline"
+      assert_response :success
+      refute MyComponent.__vc_compiled?
+    end
+  ensure
+    FileUtils.rm_f(new_template)
+  end
+
   def test_inherited_template_changes_are_reflected_on_new_request_when_cache_template_loading_is_false
     with_new_cache do
       get "/inherited_sidecar"