From 80a7c8a0cba3d9f44f69f7a716166f101f0bef33 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Wed, 6 Feb 2013 14:21:31 -0800
Subject: [PATCH] Hook class

---
 lib/vagrant/action/hook.rb            | 53 +++++++++++++++++++++++++++
 lib/vagrant/action/warden.rb          |  6 +--
 test/unit/vagrant/action/hook_test.rb | 52 ++++++++++++++++++++++++++
 3 files changed, 108 insertions(+), 3 deletions(-)
 create mode 100644 lib/vagrant/action/hook.rb
 create mode 100644 test/unit/vagrant/action/hook_test.rb

diff --git a/lib/vagrant/action/hook.rb b/lib/vagrant/action/hook.rb
new file mode 100644
index 000000000..ef8f2992d
--- /dev/null
+++ b/lib/vagrant/action/hook.rb
@@ -0,0 +1,53 @@
+module Vagrant
+  module Action
+    # This class manages hooks into existing {Builder} stacks, and lets you
+    # add and remove middleware classes. This is the primary method by which
+    # plugins can hook into built-in middleware stacks.
+    class Hook
+      # This is a hash of the middleware to prepend to a certain
+      # other middleware.
+      #
+      # @return [Hash<Class, Array<Class>>]
+      attr_reader :before_hooks
+
+      # This is a hash of the middleware to append to a certain other
+      # middleware.
+      #
+      # @return [Hash<Class, Array<Class>>]
+      attr_reader :after_hooks
+
+      # This is a list of the hooks to just prepend to the beginning
+      #
+      # @return [Array<Class>]
+      attr_reader :prepend_hooks
+
+      # This is a list of the hooks to just append to the end
+      #
+      # @return [Array<Class>]
+      attr_reader :append_hooks
+
+      def initialize
+        @before_hooks  = Hash.new { |h, k| h[k] = [] }
+        @after_hooks   = Hash.new { |h, k| h[k] = [] }
+        @prepend_hooks = []
+        @append_hooks  = []
+      end
+
+      def before(existing, new)
+        @before_hooks[existing] << new
+      end
+
+      def after(existing, new)
+        @after_hooks[existing] << new
+      end
+
+      def append(new)
+        @append_hooks << new
+      end
+
+      def prepend(new)
+        @prepend_hooks << new
+      end
+    end
+  end
+end
diff --git a/lib/vagrant/action/warden.rb b/lib/vagrant/action/warden.rb
index 5629a13f2..d01b88caf 100644
--- a/lib/vagrant/action/warden.rb
+++ b/lib/vagrant/action/warden.rb
@@ -16,9 +16,9 @@ module Vagrant
       attr_accessor :actions, :stack
 
       def initialize(actions, env)
-        @stack = []
-        @actions = actions.map { |m| finalize_action(m, env) }
-        @logger  = Log4r::Logger.new("vagrant::action::warden")
+        @stack      = []
+        @actions    = actions.map { |m| finalize_action(m, env) }
+        @logger     = Log4r::Logger.new("vagrant::action::warden")
         @last_error = nil
       end
 
diff --git a/test/unit/vagrant/action/hook_test.rb b/test/unit/vagrant/action/hook_test.rb
new file mode 100644
index 000000000..f944c3a54
--- /dev/null
+++ b/test/unit/vagrant/action/hook_test.rb
@@ -0,0 +1,52 @@
+require File.expand_path("../../../base", __FILE__)
+
+require "vagrant/action/hook"
+
+describe Vagrant::Action::Hook do
+  describe "defaults" do
+    its("after_hooks")   { should be_empty }
+    its("before_hooks")  { should be_empty }
+    its("append_hooks")  { should be_empty }
+    its("prepend_hooks") { should be_empty }
+  end
+
+  describe "before hooks" do
+    let(:existing) { "foo" }
+
+    it "should append them" do
+      subject.before(existing, 1)
+      subject.before(existing, 2)
+
+      subject.before_hooks[existing].should == [1, 2]
+    end
+  end
+
+  describe "after hooks" do
+    let(:existing) { "foo" }
+
+    it "should append them" do
+      subject.after(existing, 1)
+      subject.after(existing, 2)
+
+      subject.after_hooks[existing].should == [1, 2]
+    end
+  end
+
+  describe "append" do
+    it "should make a list" do
+      subject.append(1)
+      subject.append(2)
+
+      subject.append_hooks.should == [1, 2]
+    end
+  end
+
+  describe "prepend" do
+    it "should make a list" do
+      subject.prepend(1)
+      subject.prepend(2)
+
+      subject.prepend_hooks.should == [1, 2]
+    end
+  end
+end