1 files changed, 38 insertions, 0 deletions
diff --git a/spec/lib/kramdown/kramdown_spec.rb b/spec/lib/kramdown/kramdown_spec.rb
new file mode 100644
index 00000000000..986a8d9959e
--- /dev/null
+++ b/spec/lib/kramdown/kramdown_spec.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe 'Ensure kramdown detects invalid syntax highlighting formatters' do
+  subject { Kramdown::Document.new(options + "\n" + code).to_html }
+
+  let(:code) do
+    <<-RUBY
+~~~ ruby
+    def what?
+      42
+    end
+~~~
+    RUBY
+  end
+
+  context 'with invalid formatter' do
+    let(:options) { %({::options auto_ids="false" footnote_nr="5" syntax_highlighter="rouge" syntax_highlighter_opts="{formatter: CSV, line_numbers: true\\}" /}) }
+
+    it 'falls back to standard HTML and disallows CSV' do
+      expect(CSV).not_to receive(:new)
+      expect(::Rouge::Formatters::HTML).to receive(:new).and_call_original
+
+      expect(subject).to be_present
+    end
+  end
+
+  context 'with valid formatter' do
+    let(:options) { %({::options auto_ids="false" footnote_nr="5" syntax_highlighter="rouge" syntax_highlighter_opts="{formatter: HTMLLegacy\\}" /}) }
+
+    it 'allows formatter' do
+      expect(::Rouge::Formatters::HTMLLegacy).to receive(:new).and_call_original
+
+      expect(subject).to be_present
+    end
+  end
+end