Fix hashie#69: regression, multiple property assignments in Trash.

Heavily inspired from hashie@9a38985.

CHANGELOG.md

@@ -11,6 +11,7 @@
 * [#206](http://github.com/intridea/hashie/pull/206): Fixed stack overflow from repetitively including coercion in subclasses - [@michaelherold](https://github.com/michaelherold).
 * [#207](http://github.com/intridea/hashie/pull/207): Fixed inheritance of transformations in Trash - [@fobocaster](https://github.com/fobocaster).
 * [#209](http://github.com/intridea/hashie/pull/209): Added Hashie::Extensions::DeepFind - [@michaelherold](https://github.com/michaelherold).
+* [#69](https://github.com/intridea/hashie/pull/69): Fixed assigning multiple properties in Hashie::Trash - [@michaelherold](https://github.com/michaelherold), [@dblock](https://github.com/dblock).
 * Your contribution here.
 
 ## 3.2.0 (7/10/2014)

lib/hashie/trash.rb

@@ -26,11 +26,13 @@ def self.property(property_name, options = {})
           fail ArgumentError, "Property name (#{property_name}) and :from option must not be the same"
         end
 
-        translations[options[:from]] = property_name
+        translations[options[:from]] ||= {}
+        translations[options[:from]][property_name] = options[:with] || options[:transform_with]
 
         define_method "#{options[:from]}=" do |val|
-          with = options[:with] || options[:transform_with]
-          self[property_name] = with.respond_to?(:call) ? with.call(val) : val
+          self.class.translations[options[:from]].each do |name, with|
+            self[name] = with.respond_to?(:call) ? with.call(val) : val
+          end
         end
       else
         if options[:transform_with].respond_to? :call
@@ -82,7 +84,15 @@ def self.permitted_input_keys
     private
 
     def self.inverse_translations
-      @inverse_translations ||= Hash[translations.map(&:reverse)]
+      @inverse_translations ||= begin
+        h = {}
+        translations.each do |(property_name, property_translations)|
+          property_translations.keys.each do |k|
+            h[k] = property_name
+          end
+        end
+        h
+      end
     end
 
     # Raises an NoMethodError if the property doesn't exist

spec/hashie/trash_spec.rb

@@ -29,7 +29,7 @@ class TrashTest < Hashie::Trash
     end
 
     it 'maintains translations hash mapping from the original to the translated name' do
-      expect(TrashTest.translations[:firstName]).to eq :first_name
+      expect(TrashTest.translations[:firstName]).to eq(first_name: nil)
     end
 
     it 'maintains inverse translations hash mapping from the translated to the original name' do