Registered actions can be run. Builders can use other builders

lib/vagrant/action.rb

@@ -31,9 +31,12 @@ module Vagrant
     end
 
     # Runs the given callable object in the context of the environment.
+    # If a symbol is given as the `callable` parameter, then it is looked
+    # up in the registered actions list which are registered with {register}.
     #
     # @param [Object] callable An object which responds to `call`.
     def run(callable)
+      callable = self.class.actions[callable] if callable.kind_of?(Symbol)
       callable.call(Action::Environment.new(env))
     end
   end

lib/vagrant/action/builder.rb

@@ -37,7 +37,12 @@ module Vagrant
       #
       # @param [Class] middleware The middleware class
       def use(middleware, *args, &block)
-        stack << [middleware, args, block]
+        if middleware.kind_of?(Builder)
+          # Merge in the other builder's stack into our own
+          self.stack.concat(middleware.stack)
+        else
+          self.stack << [middleware, args, block]
+        end
       end
 
       # Converts the builder stack to a runnable action sequence.

test/vagrant/action/builder_test.rb

@@ -33,6 +33,17 @@ class ActionBuilderTest < Test::Unit::TestCase
         @instance.use 2
         assert_equal [2, [], nil], @instance.stack.last
       end
+
+      should "merge in other builder's stack" do
+        other = @klass.new do
+          use 2
+          use 3
+        end
+
+        @instance.use 1
+        @instance.use other
+        assert_equal 3, @instance.stack.length
+      end
     end
 
     context "converting to an app" do

test/vagrant/action_test.rb

@@ -10,6 +10,10 @@ class ActionTest < Test::Unit::TestCase
       @instance = @klass.new(mock_environment)
     end
 
+    teardown do
+      @klass.actions.clear
+    end
+
     should "run the callable item with the proper context" do
       callable = mock("callable")
       callable.expects(:call).with() do |env|
@@ -20,5 +24,13 @@ class ActionTest < Test::Unit::TestCase
 
       @instance.run(callable)
     end
+
+    should "run the registered callable if a symbol is given" do
+      callable = mock("callable")
+      callable.expects(:call).once
+
+      @klass.register(:call, callable)
+      @instance.run(:call)
+    end
   end
 end