deprecate empty()

Author: pmcmaw

README.md

@@ -1163,6 +1163,8 @@ Converts the case of a string or of all strings in an array to lowercase.
 
 #### `empty`
 
+**Deprecated. Puppet 5.5.0 has introduced an inbuilt `empty` function, that will take precedence over the stdlib function. See [Puppet 5.5.0 Release Notes](https://puppet.com/docs/puppet/5.5/release_notes.html#new-features).**
+
 Returns `true` if the argument is an array or hash that contains no elements, or an empty string. Returns `false` when the argument is a numerical value.
 
 *Type*: rvalue.

lib/puppet/parser/functions/empty.rb

@@ -7,6 +7,9 @@ module Puppet::Parser::Functions
   DOC
              ) do |arguments|
 
+    function_deprecation([:empty, 'This method is deprecated, this function is now shipped in puppet in versions 5.5.0 and later.
+                           For more information please see [puppet 5.5.0 release notes|https://puppet.com/docs/puppet/5.5/release_notes.html#new-features].'])
+
     raise(Puppet::ParseError, "empty(): Wrong number of arguments given (#{arguments.size} for 1)") if arguments.empty?
     value = arguments[0]
 

spec/functions/empty_spec.rb

@@ -2,7 +2,7 @@
 
 describe 'empty' do
   it { is_expected.not_to eq(nil) }
-  it { is_expected.to run.with_params.and_raise_error(Puppet::ParseError) }
+  it { is_expected.to run.with_params.and_raise_error(Puppet::ParseError) } if Puppet.version < '5.5.0'
   it {
     pending('Current implementation ignores parameters after the first.')
     is_expected.to run.with_params('one', 'two').and_raise_error(Puppet::ParseError)