core: expand IsState to support inversions

lib/vagrant/action/builtin/is_state.rb

@@ -14,6 +14,7 @@ module Vagrant
           @app    = app
           @logger = Log4r::Logger.new("vagrant::action::builtin::is_state")
           @check  = check
+          @invert = !!opts[:invert]
         end
 
         def call(env)
@@ -22,6 +23,7 @@ module Vagrant
           @logger.debug("-- Machine state: #{state}")
 
           env[:result] = @check == state
+          env[:result] = !env[:result] if @invert
           @app.call(env)
         end
       end

test/unit/vagrant/action/builtin/is_state_test.rb

@@ -15,6 +15,17 @@ describe Vagrant::Action::Builtin::IsState do
   let(:state) { double("state") }
 
   describe "#call" do
+    it "sets result to false if is proper state" do
+      state.stub(id: :foo)
+
+      subject = described_class.new(app, env, :bar)
+
+      app.should_receive(:call).with(env)
+
+      subject.call(env)
+      expect(env[:result]).to be_false
+    end
+
     it "sets result to true if is proper state" do
       state.stub(id: :foo)
 
@@ -25,5 +36,16 @@ describe Vagrant::Action::Builtin::IsState do
       subject.call(env)
       expect(env[:result]).to be_true
     end
+
+    it "inverts the result if specified" do
+      state.stub(id: :foo)
+
+      subject = described_class.new(app, env, :foo, invert: true)
+
+      app.should_receive(:call).with(env)
+
+      subject.call(env)
+      expect(env[:result]).to be_false
+    end
   end
 end