Support file extensions in uppercase

lib/active_storage_validations/content_type_validator.rb

@@ -67,7 +67,7 @@ def extension_matches_content_type?(record, attribute, attachable)
 
       extension = @attachable_filename.split('.').last
       possible_extensions = Marcel::TYPE_EXTS[@attachable_content_type]
-      return true if possible_extensions && extension.in?(possible_extensions)
+      return true if possible_extensions && extension.downcase.in?(possible_extensions)
 
       errors_options = initialize_and_populate_error_options(options, attachable)
       add_error(record, attribute, ERROR_TYPES.first, **errors_options)

test/dummy/app/models/content_type/validator/check.rb

@@ -27,6 +27,10 @@ def self.example_for(type, several: false)
   validates :extension_two_extensions_docx, content_type: 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'
   has_one_attached :extension_two_extensions_pdf
   validates :extension_two_extensions_pdf, content_type: 'application/pdf'
+  has_one_attached :extension_upcase_extension
+  validates :extension_upcase_extension, content_type: 'application/pdf'
+  has_one_attached :extension_missing_extension
+  validates :extension_missing_extension, content_type: 'application/pdf'
 
   %w(symbol string regex).each do |type|
     has_one_attached :"with_#{type}"

test/validators/content_type_validator_test.rb

@@ -126,6 +126,41 @@
           it { is_expected_to_be_valid }
         end
       end
+
+      describe "when the extension is in uppercase" do
+        subject { model.public_send(attribute).attach(pdf_file_with_extension_in_uppercase) and model }
+
+        let(:attribute) { :extension_upcase_extension }
+        let(:pdf_file_with_extension_in_uppercase) do
+          pdf_file.tap do |file|
+            file[:filename][".pdf"] = ".PDF"
+          end
+        end
+
+        it { is_expected_to_be_valid }
+      end
+
+      describe "when the extension is missing" do
+        subject { model.public_send(attribute).attach(pdf_file_without_extension) and model }
+
+        let(:attribute) { :extension_missing_extension }
+        let(:pdf_file_without_extension) do
+          pdf_file.tap do |file|
+            file[:filename][".pdf"] = ""
+          end
+        end
+        let(:error_options) do
+          {
+            authorized_types: "PDF",
+            content_type: pdf_file_without_extension[:content_type],
+            filename: pdf_file_without_extension[:filename]
+          }
+        end
+
+        it { is_expected_not_to_be_valid }
+        it { is_expected_to_have_error_message("content_type_invalid", error_options: error_options) }
+        it { is_expected_to_have_error_options(error_options) }
+      end
     end
 
     describe ":with" do