support cgi style options, such as erb?parent=json

lib/gitlab/highlight.rb

@@ -40,11 +40,11 @@ def highlight(text, continue: true, plain: false)
     private
 
     def custom_language
-      return nil if @repository.nil?
+      language_name = @repository && @repository.gitattribute(@blob_name, 'gitlab-language')
 
-      language_name = @repository.gitattribute(@blob_name, 'gitlab-language')
+      return nil unless language_name
 
-      Rouge::Lexer.find(language_name)
+      Rouge::Lexer.find_fancy(language_name)
     end
 
     def rouge_formatter(options = {})

spec/lib/gitlab/highlight_spec.rb

@@ -21,7 +21,6 @@
 
   describe 'custom highlighting from .gitattributes' do
     let(:branch) { 'gitattributes' }
-    let(:path) { 'custom-highlighting/test.gitlab-custom' }
     let(:blob) { repository.blob_at_branch(branch, path) }
 
     let(:highlighter) do
@@ -30,8 +29,20 @@
 
     before { project.change_head('gitattributes') }
 
-    it 'highlights as ruby' do
-      expect(highlighter.lexer.tag).to eq 'ruby'
+    describe 'basic language selection' do
+      let(:path) { 'custom-highlighting/test.gitlab-custom' }
+      it 'highlights as ruby' do
+        expect(highlighter.lexer.tag).to eq 'ruby'
+      end
+    end
+
+    describe 'cgi options' do
+      let(:path) { 'custom-highlighting/test.gitlab-cgi' }
+
+      it 'highlights as json with erb' do
+        expect(highlighter.lexer.tag).to eq 'erb'
+        expect(highlighter.lexer.parent.tag).to eq 'json'
+      end
     end
   end
 end

spec/support/test_env.rb

@@ -17,7 +17,7 @@ module TestEnv
     "'test'"           => 'e56497b',
     'orphaned-branch'  => '45127a9',
     'binary-encoding'  => '7b1cf43',
-    'gitattributes'    => '281d3a76'
+    'gitattributes'    => '5a62481',
   }
 
   # gitlab-test-fork is a fork of gitlab-fork, but we don't necessarily