Adding optional type for attributes

lib/active_model/serializer.rb

@@ -73,7 +73,9 @@ def attributes(*attrs)
       end
 
       def attribute(attr, options={})
-        self._attributes = _attributes.merge(attr => options[:key] || attr.to_s.gsub(/\?$/, '').to_sym)
+        self._attributes = _attributes.merge(attr.is_a?(Hash) ? attr : {attr => options[:key] || attr.to_s.gsub(/\?$/, '').to_sym})
+
+        attr = attr.keys[0] if attr.is_a? Hash
 
         unless method_defined?(attr)
           define_method attr do
@@ -175,8 +177,12 @@ def schema
             attrs[key] = column.type
           else
             # Computed attribute (method on serializer or model). We cannot
-            # infer the type, so we put nil.
-            attrs[key] = nil
+            # infer the type, so we put nil, unless specified in the attribute declaration
+            if name != key
+              attrs[name] = key
+            else
+              attrs[key] = nil
+            end
           end
         end
 

test/serializer_test.rb

@@ -493,14 +493,14 @@ class << self; self; end.class_eval do
       def can_edit; end
       def drafts; end
 
-      attributes :name, :age, :can_edit
+      attributes :name, :age, :can_edit => :boolean
       has_many :posts, :serializer => Class.new
       has_many :drafts, :serializer => Class.new
       has_one :parent, :serializer => Class.new
     end
 
     assert_equal serializer.schema, {
-      :attributes => { :name => :string, :age => :integer, :can_edit => nil },
+      :attributes => { :name => :string, :age => :integer, :can_edit => :boolean },
       :associations => {
         :posts => { :has_many => :posts },
         :drafts => nil,
@@ -1004,7 +1004,7 @@ def self.to_s
         :name => 'logo.png',
         :url => 'http://example.com/logo.png',
         :attachable => {
-          :type => :email, 
+          :type => :email,
           :id => 1
         }},
       :emails => [{