diff --git a/spec/lib/gitlab/highlight_spec.rb b/spec/lib/gitlab/highlight_spec.rb
new file mode 100644
index 0000000000000000000000000000000000000000..1620eb6c60adb507920d56cd7cbf47b8828961a5
--- /dev/null
+++ b/spec/lib/gitlab/highlight_spec.rb
@@ -0,0 +1,21 @@
+require 'spec_helper'
+
+describe Gitlab::Highlight, lib: true do
+  include RepoHelpers
+
+  let(:project) { create(:project) }
+  let(:commit) { project.commit(sample_commit.id) }
+
+  describe '.highlight_lines' do
+    let(:lines) do
+      Gitlab::Highlight.highlight_lines(project.repository, commit.id, 'files/ruby/popen.rb')
+    end
+
+    it 'should properly highlight all the lines' do
+      expect(lines[4]).to eq(%Q{<span id="LC5" class="line">  <span class="kp">extend</span> <span class="nb">self</span></span>\n})
+      expect(lines[21]).to eq(%Q{<span id="LC22" class="line">    <span class="k">unless</span> <span class="no">File</span><span class="p">.</span><span class="nf">directory?</span><span class="p">(</span><span class="n">path</span><span class="p">)</span></span>\n})
+      expect(lines[26]).to eq(%Q{<span id="LC27" class="line">    <span class="vi">@cmd_status</span> <span class="o">=</span> <span class="mi">0</span></span>\n})
+    end
+  end
+
+end