1 files changed, 34 insertions, 0 deletions
diff --git a/spec/controllers/application_controller_spec.rb b/spec/controllers/application_controller_spec.rb
index fbf116e533b..7202cee04ea 100644
--- a/spec/controllers/application_controller_spec.rb
+++ b/spec/controllers/application_controller_spec.rb
@@ -694,4 +694,38 @@ describe ApplicationController do
       expect(response).to have_gitlab_http_status(403)
     end
   end
+
+  context 'when invalid UTF-8 parameters are received' do
+    controller(described_class) do
+      def index
+        params[:text].split(' ')
+
+        render json: :ok
+      end
+    end
+
+    before do
+      sign_in user
+    end
+
+    context 'html' do
+      it 'renders 412' do
+        get :index, text: "hi \255"
+
+        expect(response).to have_gitlab_http_status(412)
+        expect(response).to render_template :precondition_failed
+      end
+    end
+
+    context 'js' do
+      it 'renders 412' do
+        get :index, text: "hi \255", format: :js
+
+        json_response = JSON.parse(response.body)
+
+        expect(response).to have_gitlab_http_status(412)
+        expect(json_response['error']).to eq('Invalid UTF-8')
+      end
+    end
+  end
 end