Add PhpUnit Hook for PrePush

Add `PhpUnit` test runner hook for `PrePush` context.

Author: taufek

config/default.yml

@@ -1129,6 +1129,13 @@ PrePush:
     command: ['ruby', '-Ilib:test', '-rminitest', "-e 'exit! Minitest.run'"]
     include: 'test/**/*_test.rb'
 
+  PhpUnit:
+    enabled: false
+    description: 'Run PhpUnit test suite'
+    command: 'vendor/bin/phpunit'
+    flags: ['--bootstrap', 'vendor/autoload.php', 'tests']
+    install_command: 'composer require --dev phpunit/phpunit'
+
   ProtectedBranches:
     enabled: false
     description: 'Check for illegal pushes to protected branches'

lib/overcommit/hook/pre_push/php_unit.rb

@@ -0,0 +1,14 @@
+module Overcommit::Hook::PrePush
+  # Runs `phpunit` test suite before push
+  #
+  # @see https://phpunit.de/
+  class PhpUnit < Base
+    def run
+      result = execute(command)
+      return :pass if result.success?
+
+      output = result.stdout + result.stderr
+      [:fail, output]
+    end
+  end
+end

spec/overcommit/hook/pre_push/php_unit_spec.rb

@@ -0,0 +1,29 @@
+require 'spec_helper'
+
+describe Overcommit::Hook::PrePush::PhpUnit do
+  let(:config)  { Overcommit::ConfigurationLoader.default_configuration }
+  let(:context) { double('context') }
+  subject       { described_class.new(config, context) }
+
+  context 'when phpunit exits successfully' do
+    before do
+      result = double('result')
+      result.stub(:success?).and_return(true)
+      subject.stub(:execute).and_return(result)
+    end
+
+    it { should pass }
+  end
+
+  context 'when phpunit exits unsucessfully' do
+    before do
+      result = double('result')
+      result.stub(:success?).and_return(false)
+      result.stub(:stdout).and_return('Some error message')
+      result.stub(:stderr).and_return('')
+      subject.stub(:execute).and_return(result)
+    end
+
+    it { should fail_hook 'Some error message' }
+  end
+end