Pass SingleLineSubject hook when commit message is empty

Author: jawshooah

lib/overcommit/hook/commit_msg/single_line_subject.rb

@@ -2,6 +2,8 @@ module Overcommit::Hook::CommitMsg
   # Ensures commit message subject lines are followed by a blank line.
   class SingleLineSubject < Base
     def run
+      return :pass if empty_message?
+
       unless commit_message_lines[1].to_s.strip.empty?
         return :warn, 'Subject should be one line and followed by a blank line'
       end

spec/overcommit/hook/commit_msg/single_line_subject_spec.rb

@@ -7,6 +7,13 @@
 
   before do
     subject.stub(:commit_message_lines).and_return(commit_msg.split("\n"))
+    subject.stub(:empty_message?).and_return(commit_msg.empty?)
+  end
+
+  context 'when commit message is empty' do
+    let(:commit_msg) { '' }
+
+    it { should pass }
   end
 
   context 'when subject is separated from body by a blank line' do