Refactor dig44 function

The current implementation of the dig44 function has the
following problems:
* Doesn't recognise Puppet4's :undef value as an empty value
  and doesn't return the default value.
* Doesn't make a different between false and nil value
  and returns the default value for a non-empty false value

1 files changed, 29 insertions, 12 deletions

diff --git a/lib/puppet/parser/functions/dig44.rb b/lib/puppet/parser/functions/dig44.rb
index a7de363..d703380 100644
--- a/lib/puppet/parser/functions/dig44.rb
+++ b/lib/puppet/parser/functions/dig44.rb
@@ -1,23 +1,30 @@
-#
-# dig44.rb
+#		
+# dig44.rb		
 #
 
 module Puppet::Parser::Functions
-  newfunction(:dig44, :type => :rvalue, :doc => <<-EOS
+  newfunction(
+      :dig44,
+      :type => :rvalue,
+      :arity => -2,
+      :doc => <<-eos
 DEPRECATED: This function has been replaced in puppet 4.5.0.
 
-Looks up into a complex structure of arrays and hashes and returns nil
+Looks up into a complex structure of arrays and hashes and returns a value
 or the default value if nothing was found.
 
-Path is an array of keys to be looked up in data argument. The function
-will go down the structure and try to extract the required value.
+Key can contain slashes to describe path components. The function will go down
+the structure and try to extract the required value.
 
 $data = {
   'a' => {
     'b' => [
       'b1',
       'b2',
-      'b3' ]}}
+      'b3',
+    ]
+  }
+}
 
 $value = dig44($data, ['a', 'b', '2'], 'not_found')
 => $value = 'b3'
@@ -29,18 +36,18 @@ b -> second hash key
 not_found -> (optional) will be returned if there is no value or the path
 did not match. Defaults to nil.
 
-In addition to the required "path" argument, "dig44" accepts default
+In addition to the required "key" argument, the function accepts a default
 argument. It will be returned if no value was found or a path component is
 missing. And the fourth argument can set a variable path separator.
-    EOS
-             ) do |arguments|
+  eos
+  ) do |arguments|
     # Two arguments are required
     raise(Puppet::ParseError, "dig44(): Wrong number of arguments " +
                               "given (#{arguments.size} for at least 2)") if arguments.size < 2
 
     data, path, default = *arguments
 
-    if !(data.is_a?(Hash) || data.is_a?(Array))
+    unless data.is_a?(Hash) or data.is_a?(Array)
       raise(Puppet::ParseError, "dig44(): first argument must be a hash or an array, " <<
                                 "given #{data.class.name}")
     end
@@ -50,7 +57,17 @@ missing. And the fourth argument can set a variable path separator.
                                 "given #{path.class.name}")
     end
 
-    value = path.reduce(data) { |h, k| (h.is_a?(Hash) || h.is_a?(Array)) ? h[k] : break }
+    value = path.reduce(data) do |structure, key|
+      if structure.is_a? Hash or structure.is_a? Array
+        if structure.is_a? Array
+          key = Integer key rescue break
+        end
+        break if structure[key].nil? or structure[key] == :undef
+        structure[key]
+      else
+        break
+      end
+    end
     value.nil? ? default : value
   end
 end