Print commit message when commit_msg hooks fail

lib/overcommit/hook_context/base.rb

@@ -102,6 +102,13 @@ def input_lines
       @input_lines ||= input_string.split("\n")
     end
 
+    # Returns a message to display on failure.
+    #
+    # @return [String]
+    def post_fail_message
+      nil
+    end
+
     private
 
     def filter_modified_files(modified_files)

lib/overcommit/hook_context/commit_msg.rb

@@ -31,6 +31,10 @@ def commit_message_file
       @args[0]
     end
 
+    def post_fail_message
+      "Failed commit message:\n" + commit_message_lines.join
+    end
+
     private
 
     def raw_commit_message_lines

lib/overcommit/hook_runner.rb

@@ -74,7 +74,14 @@ def run_hooks
 
         print_results
 
-        !(@failed || @interrupted)
+        hook_failed = @failed || @interrupted
+
+        if hook_failed
+          message = @context.post_fail_message
+          @printer.after(message) unless message.nil?
+        end
+
+        !hook_failed
       else
         @printer.nothing_to_run
         true # Run was successful

lib/overcommit/printer.rb

@@ -77,6 +77,12 @@ def run_succeeded
       end
     end
 
+    def after(message)
+      log.newline
+      log.log message
+      log.newline
+    end
+
     private
 
     def print_header(hook)

spec/overcommit/hook_context/base_spec.rb

@@ -23,4 +23,10 @@
 
     it { should == ['line 1', 'line 2'] }
   end
+
+  describe '#post_fail_message' do
+    subject { context.post_fail_message }
+
+    it { should be_nil }
+  end
 end

spec/overcommit/hook_context/commit_msg_spec.rb

@@ -85,4 +85,12 @@
       it { should == false }
     end
   end
+
+  describe '#post_fail_message' do
+    subject { context.post_fail_message }
+
+    it 'returns printable log of commit message' do
+      subject.should == "Failed commit message:\nSome commit message\n"
+    end
+  end
 end