Report the attribute on ActiveRecord::SerializationTypeMismatch

3 files changed, 7 insertions, 6 deletions

diff --git a/activerecord/lib/active_record/attribute_methods/serialization.rb b/activerecord/lib/active_record/attribute_methods/serialization.rb
index 945192fe04..4d9aff76cc 100644
--- a/activerecord/lib/active_record/attribute_methods/serialization.rb
+++ b/activerecord/lib/active_record/attribute_methods/serialization.rb
@@ -54,7 +54,7 @@ module ActiveRecord
           elsif [:load, :dump].all? { |x| class_name_or_coder.respond_to?(x) }
             class_name_or_coder
           else
-            Coders::YAMLColumn.new(class_name_or_coder)
+            Coders::YAMLColumn.new(attr_name, class_name_or_coder)
           end
 
           decorate_attribute_type(attr_name, :serialize) do |type|
diff --git a/activerecord/lib/active_record/coders/yaml_column.rb b/activerecord/lib/active_record/coders/yaml_column.rb
index 4b06987f08..2136da43fe 100644
--- a/activerecord/lib/active_record/coders/yaml_column.rb
+++ b/activerecord/lib/active_record/coders/yaml_column.rb
@@ -5,7 +5,8 @@ module ActiveRecord
     class YAMLColumn # :nodoc:
       attr_accessor :object_class
 
-      def initialize(object_class = Object)
+      def initialize(attr_name, object_class = Object)
+        @attr_name = attr_name
         @object_class = object_class
         check_arity_of_constructor
       end
@@ -31,7 +32,7 @@ module ActiveRecord
       def assert_valid_value(obj)
         unless obj.nil? || obj.is_a?(object_class)
           raise SerializationTypeMismatch,
-            "Attribute was supposed to be a #{object_class}, but was a #{obj.class}. -- #{obj.inspect}"
+            "Attribute `#{@attr_name}` was supposed to be a #{object_class}, but was a #{obj.class}. -- #{obj.inspect}"
         end
       end
 
diff --git a/activerecord/lib/active_record/store.rb b/activerecord/lib/active_record/store.rb
index d4be20d999..006afe7495 100644
--- a/activerecord/lib/active_record/store.rb
+++ b/activerecord/lib/active_record/store.rb
@@ -78,7 +78,7 @@ module ActiveRecord
 
     module ClassMethods
       def store(store_attribute, options = {})
-        serialize store_attribute, IndifferentCoder.new(options[:coder])
+        serialize store_attribute, IndifferentCoder.new(store_attribute, options[:coder])
         store_accessor(store_attribute, options[:accessors]) if options.has_key? :accessors
       end
 
@@ -177,12 +177,12 @@ module ActiveRecord
       end
 
       class IndifferentCoder # :nodoc:
-        def initialize(coder_or_class_name)
+        def initialize(attr_name, coder_or_class_name)
           @coder =
             if coder_or_class_name.respond_to?(:load) && coder_or_class_name.respond_to?(:dump)
               coder_or_class_name
             else
-              ActiveRecord::Coders::YAMLColumn.new(coder_or_class_name || Object)
+              ActiveRecord::Coders::YAMLColumn.new(attr_name, coder_or_class_name || Object)
             end
         end