Check variant image properties directly

test/controllers/variants_controller_test.rb

@@ -18,6 +18,9 @@ class ActiveStorage::VariantsControllerTest < ActionController::TestCase
       variation_key: ActiveStorage::Variation.encode(resize: "100x100") }
 
     assert_redirected_to /racecar.jpg\?disposition=inline/
-    assert_equal_image_dimensions "racecar-100x100.jpg", @blob.variant(resize: "100x100")
+
+    image = read_image_variant(@blob.variant(resize: "100x100"))
+    assert_equal 100, image.width
+    assert_equal 67, image.height
   end
 end

test/models/variant_test.rb

@@ -8,16 +8,20 @@ class ActiveStorage::VariantTest < ActiveSupport::TestCase
 
   test "resized variation" do
     variant = @blob.variant(resize: "100x100").processed
-
     assert_match /racecar.jpg/, variant.service_url
-    assert_equal_image_dimensions "racecar-100x100.jpg", variant
+
+    image = read_image_variant(variant)
+    assert_equal 100, image.width
+    assert_equal 67, image.height
   end
 
   test "resized and monochrome variation" do
     variant = @blob.variant(resize: "100x100", monochrome: true).processed
-
     assert_match /racecar.jpg/, variant.service_url
-    assert_equal_image_dimensions "racecar-100x100-monochrome.jpg", variant
-    assert_equal_image_colorspace "racecar-100x100-monochrome.jpg", variant
+
+    image = read_image_variant(variant)
+    assert_equal 100, image.width
+    assert_equal 67, image.height
+    assert_equal "Grayscale", image.colorspace
   end
 end

test/test_helper.rb

@@ -44,28 +44,10 @@ class ActiveSupport::TestCase
         io: file_fixture(filename).open,
         filename: filename, content_type: content_type
     end
-  
+
     def create_blob_before_direct_upload(filename: "hello.txt", byte_size:, checksum:, content_type: "text/plain")
       ActiveStorage::Blob.create_before_direct_upload! filename: filename, byte_size: byte_size, checksum: checksum, content_type: content_type
     end
-  
-
-    def assert_equal_image_dimensions(fixture_filename, variant)
-      expected_image, actual_image = read_image_fixture(fixture_filename), read_image_variant(variant)
-      
-      assert_equal expected_image.width, actual_image.width
-      assert_equal expected_image.height, actual_image.height
-    end
-
-    def assert_equal_image_colorspace(fixture_filename, variant)
-      expected_image, actual_image = read_image_fixture(fixture_filename), read_image_variant(variant)
-      
-      assert_equal expected_image.colorspace, actual_image.colorspace
-    end
-
-    def read_image_fixture(fixture_filename)
-      MiniMagick::Image.open file_fixture(fixture_filename)
-    end
 
     def read_image_variant(variant)
       MiniMagick::Image.open variant.service.send(:path_for, variant.key)