Add private function back and forward to assert_private with deprecation warning

lib/puppet/parser/functions/private.rb

@@ -0,0 +1,17 @@
+#
+# private.rb
+#
+
+module Puppet::Parser::Functions
+  newfunction(:private, :doc => <<-'EOS'
+    DEPRECATED: Sets the current class or definition as private.
+    Calling the class or definition from outside the current module will fail.
+  EOS
+  ) do |args|
+    warning("private() DEPRECATED: This function will cease to function on Puppet 4; please use assert_private() before upgrading to puppet 4 for backwards-compatibility, or migrate to the new parser's typing system.")
+    if !Puppet::Parser::Functions.autoloader.loaded?(:assert_private)
+      Puppet::Parser::Functions.autoloader.load(:assert_private)
+    end
+    function_assert_private([(args[0] unless args.size < 1)])
+  end
+end

spec/functions/private_spec.rb

@@ -0,0 +1,60 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper'
+
+describe Puppet::Parser::Functions.function(:private) do
+  let(:scope) { PuppetlabsSpec::PuppetInternals.scope }
+
+  subject do
+    function_name = Puppet::Parser::Functions.function(:private)
+    scope.method(function_name)
+  end
+
+  it 'should issue a warning' do
+    scope.expects(:warning).with("private() DEPRECATED: This function will cease to function on Puppet 4; please use assert_private() before upgrading to puppet 4 for backwards-compatibility, or migrate to the new parser's typing system.")
+    subject.call []
+  end
+
+  context "when called from inside module" do
+    it "should not fail" do
+      scope.expects(:lookupvar).with('module_name').returns('foo')
+      scope.expects(:lookupvar).with('caller_module_name').returns('foo')
+      expect {
+        subject.call []
+      }.not_to raise_error
+    end
+  end
+
+  context "with an explicit failure message" do
+    it "prints the failure message on error" do
+      scope.expects(:lookupvar).with('module_name').returns('foo')
+      scope.expects(:lookupvar).with('caller_module_name').returns('bar')
+      expect {
+        subject.call ['failure message!']
+      }.to raise_error Puppet::ParseError, /failure message!/
+    end
+  end
+
+  context "when called from private class" do
+    it "should fail with a class error message" do
+      scope.expects(:lookupvar).with('module_name').returns('foo')
+      scope.expects(:lookupvar).with('caller_module_name').returns('bar')
+      scope.source.expects(:name).returns('foo::baz')
+      scope.source.expects(:type).returns('hostclass')
+      expect {
+        subject.call []
+      }.to raise_error Puppet::ParseError, /Class foo::baz is private/
+    end
+  end
+
+  context "when called from private definition" do
+    it "should fail with a class error message" do
+      scope.expects(:lookupvar).with('module_name').returns('foo')
+      scope.expects(:lookupvar).with('caller_module_name').returns('bar')
+      scope.source.expects(:name).returns('foo::baz')
+      scope.source.expects(:type).returns('definition')
+      expect {
+        subject.call []
+      }.to raise_error Puppet::ParseError, /Definition foo::baz is private/
+    end
+  end
+end