Extract test helper for image blob fixtures

test/controllers/variants_controller.rb

@@ -6,12 +6,10 @@
 
 class ActiveStorage::VariantsControllerTest < ActionController::TestCase
   setup do
-    @blob = ActiveStorage::Blob.create_after_upload! \
-      filename: "racecar.jpg", content_type: "image/jpeg",
-      io: File.open(File.expand_path("../../fixtures/files/racecar.jpg", __FILE__))
-
     @routes = Routes
     @controller = ActiveStorage::VariantsController.new
+
+    @blob = create_image_blob filename: "racecar.jpg"
   end
 
   test "showing variant inline" do

test/test_helper.rb

@@ -33,6 +33,12 @@ class ActiveSupport::TestCase
     def create_blob(data: "Hello world!", filename: "hello.txt", content_type: "text/plain")
       ActiveStorage::Blob.create_after_upload! io: StringIO.new(data), filename: filename, content_type: content_type
     end
+
+    def create_image_blob(filename: "racecar.jpg", content_type: "image/jpeg")
+      ActiveStorage::Blob.create_after_upload! \
+        io: File.open(File.expand_path("../fixtures/files/#{filename}", __FILE__)),
+        filename: filename, content_type: content_type
+    end
 end
 
 require "action_controller"

test/variant_test.rb

@@ -4,9 +4,7 @@
 
 class ActiveStorage::VariantTest < ActiveSupport::TestCase
   setup do
-    @blob = ActiveStorage::Blob.create_after_upload! \
-      filename: "racecar.jpg", content_type: "image/jpeg",
-      io: File.open(File.expand_path("../fixtures/files/racecar.jpg", __FILE__))
+    @blob = create_image_blob filename: "racecar.jpg"
   end
 
   test "resized variation" do