(#8708) Add has_key function

It is difficult to use existance of keys in a hash
as a boolean condition in Puppet (see #8705)

This function provides a working solution until
the underlying issue in Puppet can be resolved.

Reviewed-by: Jeff McCune

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/has_key.rb b/lib/puppet/parser/functions/has_key.rb
new file mode 100644
index 0000000..9c1c4c3
--- /dev/null
+++ b/lib/puppet/parser/functions/has_key.rb
@@ -0,0 +1,27 @@
+module Puppet::Parser::Functions
+
+  newfunction(:has_key, :type => :rvalue, :doc => <<-'ENDHEREDOC') do |args|
+    determine if a hash has a certain key value.
+
+    Example:
+      $my_hash = {'key_one' => 'value_one'}
+      if has_key($my_hash, 'key_two') {
+        notice('we will not reach here')
+      }
+      if has_key($my_hash, 'key_one') {
+        notice('this will be printed')
+      }
+
+    ENDHEREDOC
+
+    unless args.length == 2
+      raise Puppet::ParseError, ("has_key(): wrong number of arguments (#{args.length}; must be 2)")
+    end
+    unless args[0].is_a?(Hash)
+      raise Puppet::ParseError, "has_key(): expects the first argument to be a hash, got #{args[0].inspect} which is of type #{args[0].class}"
+    end
+    args[0].has_key?(args[1])
+
+  end
+
+end