Allow specifying a default value in overloaded properties

activerecord/lib/active_record/properties.rb

@@ -14,6 +14,17 @@ module ClassMethods
       # Active Record's type casting behavior, as well as adding support for user defined
       # types.
       #
+      # +name+ The name of the methods to define attribute methods for, and the column which
+      # this will persist to.
+      #
+      # +cast_type+ A type object that contains information about how to type cast the value.
+      # See the examples section for more information.
+      #
+      # ==== Options
+      # The options hash accepts the following options:
+      #
+      # +default+ is the default value that the column should use on a new record.
+      #
       # ==== Examples
       #
       # The type detected by Active Record can be overriden.
@@ -62,11 +73,11 @@ module ClassMethods
       #
       #   store_listing = StoreListing.new(price_in_cents: '$10.00')
       #   store_listing.price_in_cents # => 1000
-      def property(name, cast_type)
+      def property(name, cast_type, options = {})
         name = name.to_s
         clear_properties_cache
         # Assign a new hash to ensure that subclasses do not share a hash
-        self.user_provided_columns = user_provided_columns.merge(name => connection.new_column(name, nil, cast_type))
+        self.user_provided_columns = user_provided_columns.merge(name => connection.new_column(name, options[:default], cast_type))
       end
 
       # Returns an array of column objects for the table associated with this class.

activerecord/test/cases/custom_properties_test.rb

@@ -4,6 +4,7 @@ class OverloadedType < ActiveRecord::Base
   property :overloaded_float, Type::Integer.new
   property :overloaded_string_with_limit, Type::String.new(limit: 50)
   property :non_existent_decimal, Type::Decimal.new
+  property :string_with_default, Type::String.new, default: 'the overloaded default'
 end
 
 class ChildOfOverloadedType < OverloadedType
@@ -62,12 +63,12 @@ def test_nonexistent_property
       end
     end
 
-    def test_overloaded_properties_have_no_default
+    def test_changing_defaults
       data = OverloadedType.new
       unoverloaded_data = UnoverloadedType.new
 
-      assert_nil data.overloaded_float
-      assert unoverloaded_data.overloaded_float
+      assert_equal 'the overloaded default', data.string_with_default
+      assert_equal 'the original default', unoverloaded_data.string_with_default
     end
 
     def test_children_inherit_custom_properties
@@ -84,7 +85,7 @@ def test_children_can_override_parents
 
     def test_overloading_properties_does_not_change_column_order
       column_names = OverloadedType.column_names
-      assert_equal %w(id overloaded_float unoverloaded_float overloaded_string_with_limit non_existent_decimal), column_names
+      assert_equal %w(id overloaded_float unoverloaded_float overloaded_string_with_limit string_with_default non_existent_decimal), column_names
     end
   end
 end

activerecord/test/schema/schema.rb

@@ -860,6 +860,7 @@ def except(adapter_names_to_exclude)
     t.float :overloaded_float, default: 500
     t.float :unoverloaded_float
     t.string :overloaded_string_with_limit, limit: 255
+    t.string :string_with_default, default: 'the original default'
   end
 end