1 files changed, 10 insertions, 0 deletions
diff --git a/spec/lib/banzai/filter/plantuml_filter_spec.rb b/spec/lib/banzai/filter/plantuml_filter_spec.rb
index dcfeb2ce3ba..4373af90cde 100644
--- a/spec/lib/banzai/filter/plantuml_filter_spec.rb
+++ b/spec/lib/banzai/filter/plantuml_filter_spec.rb
@@ -15,6 +15,16 @@ RSpec.describe Banzai::Filter::PlantumlFilter do
     expect(doc.to_s).to eq output
   end
 
+  it 'allows the lang attribute on the code tag to support RST files processed by gitlab-markup gem' do
+    stub_application_setting(plantuml_enabled: true, plantuml_url: "http://localhost:8080")
+
+    input = '<pre><code lang="plantuml">Bob -> Sara : Hello</code></pre>'
+    output = '<img class="plantuml" src="http://localhost:8080/png/U9npoazIqBLJ24uiIbImKl18pSd91m0rkGMq" data-diagram="plantuml" data-diagram-src="data:text/plain;base64,Qm9iIC0+IFNhcmEgOiBIZWxsbw==">'
+    doc = filter(input)
+
+    expect(doc.to_s).to eq output
+  end
+
   it 'does not replace plantuml pre tag with img tag if disabled' do
     stub_application_setting(plantuml_enabled: false)