Fix uses of .keys.reject, .keys.select, .keys.inject.

Author: jperville

lib/json/ld/expand.rb

@@ -44,10 +44,9 @@ def expand(input, active_property, context, ordered: true)
         output_object = {}
 
         # See if keys mapping to @type have terms with a local context
-        input.keys.select do |key|
-          context.expand_iri(key, vocab: true) == '@type'
-        end.each do |key|
-          Array(input[key]).each do |term|
+        input.each_pair do |key, val|
+          next unless context.expand_iri(key, vocab: true) == '@type'
+          Array(val).each do |term|
             term_context = context.term_definitions[term].context if context.term_definitions[term]
             context = term_context ? context.parse(term_context) : context
           end
@@ -303,7 +302,7 @@ def expand_object(input, active_property, context, output_object, ordered: false
             end
 
             # If expanded value contains members other than @reverse:
-            unless value.keys.reject {|k| k == '@reverse'}.empty?
+            if !value.key?('@reverse') || value.length > 1
               # If result does not have an @reverse member, create one and set its value to an empty JSON object.
               reverse_map = output_object['@reverse'] ||= {}
               value.each do |property, items|

lib/json/ld/frame.rb

@@ -490,7 +490,11 @@ def add_frame_output(parent, property, output)
     # @param [Hash] flags the current framing flags.
     # @return [Array<Hash>] the implicit frame.
     def create_implicit_frame(flags)
-      flags.keys.inject({}) {|memo, key| memo["@#{key}"] = [flags[key]]; memo}
+      {}.tap do |memo|
+        flags.each_pair do |key, val|
+          memo["@#{key}"] = [val]
+        end
+      end
     end
 
   private

lib/json/ld/resource.rb

@@ -110,19 +110,19 @@ def hash
     # @return [Hash] deresolved attribute hash
     def deresolve
       node_definition = if resolved?
-        deresolved = attributes.keys.inject({}) do |memo, prop|
-          value = attributes[prop]
-          memo[prop] = case value
-          when Resource
-            {'id' => value.id}
-          when Array
-            value.map do |v|
-              v.is_a?(Resource) ? {'id' => v.id} : v
+        deresolved = [].tap do |memo|
+          attributes.each_pair do |prop, value|
+            memo[prop] = case value
+            when Resource
+              {'id' => value.id}
+            when Array
+              value.map do |v|
+                v.is_a?(Resource) ? {'id' => v.id} : v
+              end
+            else
+              value
             end
-          else
-            value
           end
-          memo
         end
         deresolved
       else

lib/json/ld/utils.rb

@@ -20,7 +20,7 @@ def node?(value)
     # @param [Object] value
     # @return [Boolean]
     def node_reference?(value)
-      value.is_a?(Hash) && value.keys == %w(@id)
+      value.is_a?(Hash) && value.length == 1 && value.key?('@id')
     end
 
     ##