Add Hermann::Timeout abstraction for 1.8/1.9 compatible timeout support

Gemfile

@@ -7,4 +7,5 @@ gem 'pry'
 group :test do
   gem 'rspec', '~> 3.0.0'
   gem 'rspec-its'
+  gem 'system_timer', :platform => :mri_18
 end

Gemfile.lock

@@ -27,6 +27,7 @@ GEM
       rspec-support (~> 3.0.0)
     rspec-support (3.0.4)
     slop (3.5.0)
+    system_timer (1.2.4)
 
 PLATFORMS
   ruby
@@ -37,3 +38,4 @@ DEPENDENCIES
   rake-compiler
   rspec (~> 3.0.0)
   rspec-its
+  system_timer

lib/hermann/timeout.rb

@@ -0,0 +1,37 @@
+begin
+  require 'system_timer'
+  module Hermann
+    class Timeout
+      USE_SYSTEM_TIMER = true
+    end
+  end
+rescue LoadError
+  require 'timeout'
+
+  if RUBY_VERSION == '1.8.7'
+    puts ">>> You are running on 1.8.7 without SystemTimer"
+    puts ">>> which means Hermann::Timeout will not work as expected"
+  end
+  module Hermann
+    class Timeout
+      USE_SYSTEM_TIMER = false
+    end
+  end
+end
+
+module Hermann
+  class Timeout
+    def self.system_timer?
+      Hermann::Timeout::USE_SYSTEM_TIMER
+    end
+
+    def self.timeout(seconds, klass=nil, &block)
+      if system_timer?
+        SystemTimer.timeout_after(seconds, klass, &block)
+      else
+        ::Timeout.timeout(seconds, klass, &block)
+      end
+    end
+  end
+end
+

spec/timeout_spec.rb

@@ -0,0 +1,31 @@
+require 'spec_helper'
+require 'hermann/timeout'
+
+# Forward declare the module so this will work even without SystemTimer
+# installed (e.g. non-1.8.7)
+module SystemTimer; end
+
+describe Hermann::Timeout do
+  describe '#timeout' do
+    let(:seconds) { 5 }
+    let(:result) { 'rspec' }
+    subject(:timeout!) { described_class.timeout(seconds) { result } }
+
+    context 'with system_timer' do
+      before :each do
+        expect(described_class).to receive(:system_timer?).and_return(true)
+        expect(SystemTimer).to receive(:timeout_after).and_return(result)
+      end
+
+      it { should eql(result) }
+    end
+
+    context 'without system_timer' do
+      before :each do
+        expect(described_class).to receive(:system_timer?).and_return(false)
+      end
+
+      it { should eql(result) }
+    end
+  end
+end