Live output option for rspec command

lib/overcommit/hook/pre_push/r_spec.rb

@@ -6,7 +6,7 @@ module Overcommit::Hook::PrePush
   # @see http://rspec.info/
   class RSpec < Base
     def run
-      result = execute(command)
+      result = execute(command, live_output: config['live_output'])
       return :pass if result.success?
 
       output = result.stdout + result.stderr

lib/overcommit/subprocess.rb

@@ -31,7 +31,7 @@ def spawn(args, options = {})
 
         process = ChildProcess.build(*args)
 
-        out, err = assign_output_streams(process)
+        out, err = assign_output_streams(process, options)
 
         process.duplex = true if options[:input] # Make stdin available if needed
         process.start
@@ -48,10 +48,7 @@ def spawn(args, options = {})
         end
         process.wait
 
-        err.rewind
-        out.rewind
-
-        Result.new(process.exit_code, out.read, err.read)
+        build_result(process, out, err, options)
       end
 
       # Spawns a new process in the background using the given array of
@@ -85,14 +82,28 @@ def win32_prepare_args(args)
 
       # @param process [ChildProcess]
       # @return [Array<IO>]
-      def assign_output_streams(process)
+      def assign_output_streams(process, options = {})
+        if options[:live_output]
+          process.io.inherit!
+          return []
+        end
+
         %w[out err].map do |stream_name|
           ::Tempfile.new(stream_name).tap do |stream|
             stream.sync = true
             process.io.send("std#{stream_name}=", stream)
           end
         end
       end
+
+      def build_result(process, out, err, options = {})
+        return Result.new(process.exit_code, '', '') if options[:live_output]
+
+        err.rewind
+        out.rewind
+
+        Result.new(process.exit_code, out.read, err.read)
+      end
     end
   end
 end

spec/overcommit/hook/pre_push/r_spec_spec.rb

@@ -77,4 +77,47 @@
       it { should fail_hook }
     end
   end
+
+  context 'when live_output option is true' do
+    let(:config) do
+      Overcommit::ConfigurationLoader.default_configuration.merge(
+        Overcommit::Configuration.new(
+          'PrePush' => {
+            'RSpec' => {
+              'live_output' => true
+            }
+          }
+        )
+      )
+    end
+    let(:result) { double('result') }
+
+    before do
+      result.stub(:success?).and_return(true)
+    end
+
+    it 'calls execute with the live_output flag set' do
+      expect(subject).to receive(:execute).with(['rspec'], live_output: true).and_return(result)
+      expect(subject).to pass
+    end
+
+    context do
+      let(:child_process) { double('child process') }
+      let(:io) { double('io') }
+
+      it 'the child process inherits the io' do
+        io.stub(:inherit!)
+        child_process.stub(io: io, start: nil, wait: nil, exit_code: 0)
+        expect(ChildProcess).to receive(:build).with('rspec').and_return(child_process)
+        expect(subject).to pass
+      end
+
+      it 'the child process inherits the io' do
+        io.stub(:inherit!)
+        child_process.stub(io: io, start: nil, wait: nil, exit_code: 1)
+        expect(ChildProcess).to receive(:build).with('rspec').and_return(child_process)
+        expect(subject).to fail_hook
+      end
+    end
+  end
 end