added pp2r method to Scope

CHANGELOG

@@ -1,3 +1,5 @@
+2014-01-28 Pawel Tomulik <ptomulik@meil.pw.edu.pl>
+  * added pp2r method to Scope
 2014-01-27 Pawel Tomulik <ptomulik@meil.pw.edu.pl>
   * release 0.0.15
   * added call_macro to scope and fixed lambda binding issues

lib/puppet/parser/macros.rb

@@ -4,12 +4,29 @@
 # Monkey patches to Scope, so we have convenient access to some methods from
 # macros.
 class Puppet::Parser::Scope
-  # FIXME: I believe I should use environment that is bound to scope, not the
-  # Macros.default_environment, but at the moment I have no idea where to find
-  # it
+  # Call macro registered with {Puppet::Parser::Macros.newmacro}
+  #
+  # @param name [String] macro name, e.g. `'foo::bar'`,
+  # @param args [Array] arguments to be provided to the macro,
+  # @param options [Hash] additional options, see {Puppet::Parser::Macros.call_macro}
+  # @param env [Puppet::Node::Environment] puppet environment,
+  # @return the result of macro evaluation
   def call_macro(name, args = [], options = {}, env = Puppet::Parser::Macros.default_environment)
+    # FIXME: I believe I should use environment that is bound to scope, not the
+    # Macros.default_environment, but at the moment I have no idea where to
+    # find it
     Puppet::Parser::Macros.call_macro(self,name,args,options,env)
   end
+
+  # Convert puppet value to ruby.
+  #
+  # This converts empty strings and :undefs to nil.
+  #
+  # @param v [String|Symbol] value to be converted
+  # @return converted value
+  def pp2r(v)
+    (v.equal?(:undef) or v == '') ? nil : v
+  end
 end
 
 module Puppet::Parser::Macros; end

spec/unit/puppet/parser/macros_spec.rb

@@ -628,6 +628,7 @@
 
 describe Puppet::Parser::Scope do
   it { should respond_to :call_macro }
+  it { should respond_to :pp2r }
   let(:subject) { PuppetlabsSpec::PuppetInternals.scope }
   describe 'call_macro' do
     context 'call_macro("foo")' do
@@ -651,5 +652,22 @@
         subject.call_macro("foo",[],:opts,:env1)
       end
     end
+    describe 'pp2r' do
+      context 'pp2r(:foo)' do
+        it { subject.pp2r(:foo).should be :foo }
+      end
+      context 'pp2r("foo")' do
+        it { subject.pp2r("foo").should == "foo" }
+      end
+      context 'pp2r(nil)' do
+        it { subject.pp2r(nil).should be_nil }
+      end
+      context 'pp2r("")' do
+        it { subject.pp2r("").should be_nil }
+      end
+      context 'pp2r(:undef)' do
+        it { subject.pp2r(:undef).should be_nil }
+      end
+    end
   end
 end