1 files changed, 30 insertions, 0 deletions
diff --git a/activerecord/lib/active_record/type/boolean.rb b/activerecord/lib/active_record/type/boolean.rb
new file mode 100644
index 0000000000..978d16d524
--- /dev/null
+++ b/activerecord/lib/active_record/type/boolean.rb
@@ -0,0 +1,30 @@
+module ActiveRecord
+  module Type
+    class Boolean < Value # :nodoc:
+      def type
+        :boolean
+      end
+
+      private
+
+      def cast_value(value)
+        if value == ''
+          nil
+        elsif ConnectionAdapters::Column::TRUE_VALUES.include?(value)
+          true
+        else
+          if !ConnectionAdapters::Column::FALSE_VALUES.include?(value)
+            ActiveSupport::Deprecation.warn(<<-MSG.squish)
+              You attempted to assign a value which is not explicitly `true` or `false`
+              to a boolean column. Currently this value casts to `false`. This will
+              change to match Ruby's semantics, and will cast to `true` in Rails 5.
+              If you would like to maintain the current behavior, you should
+              explicitly handle the values you would like cast to `false`.
+            MSG
+          end
+          false
+        end
+      end
+    end
+  end
+end