Move controllers to default engine location for auto loading

Rakefile

@@ -3,6 +3,7 @@ require "bundler/gem_tasks"
 require "rake/testtask"
 
 Rake::TestTask.new do |test|
+  test.libs << "app/controllers"
   test.libs << "test"
   test.test_files = FileList["test/**/*_test.rb"]
   test.warning = false

app/controllers/active_storage/variants_controller.rb

+class ActiveStorage::VariantsController < ActionController::Base
+  def show
+    if blob_key = decode_verified_blob_key
+      redirect_to processed_variant_for(blob_key).url(disposition: disposition_param)
+    else
+      head :not_found
+    end
+  end
+
+  private
+    def decode_verified_blob_key
+      ActiveStorage::VerifiedKeyWithExpiration.decode(params[:encoded_blob_key])
+    end
+
+    def processed_variant_for(blob_key)
+      ActiveStorage::Variant.find_or_process_by!(blob_key: blob_key, encoded_variant_key: params[:encoded_variant_key])
+    end
+
+    def disposition_param
+      params[:disposition].presence_in(%w( inline attachment )) || 'inline'
+    end
+end

lib/active_storage/direct_uploads_controller.rb

-require "action_controller"
-require "active_storage/blob"
-
-class ActiveStorage::DirectUploadsController < ActionController::Base
-  def create
-    blob = ActiveStorage::Blob.create_before_direct_upload!(blob_args)
-    render json: { url: blob.url_for_direct_upload, sgid: blob.to_sgid.to_param }
-  end
-
-  private
-    def blob_args
-      params.require(:blob).permit(:filename, :byte_size, :checksum, :content_type, :metadata).to_h.symbolize_keys
-    end
-end