Push multi-parameter assignement into the types

This allows us to remove `Type::Value#klass`, as it was only used for
multi-parameter assignment to reach into the types internals. The
relevant type objects now accept a hash in addition to their previous
accepted arguments to `type_cast_from_user`. This required minor
modifications to the tests, since previously they were relying on the
fact that mulit-parameter assignement was reaching into the internals of
time zone aware attributes. In reaility, changing those properties at
runtime wouldn't change the accessor methods for all other forms of
assignment.

1 files changed, 11 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/type/date_time.rb b/activerecord/lib/active_record/type/date_time.rb
index 0a737815bc..922f0d8fef 100644
--- a/activerecord/lib/active_record/type/date_time.rb
+++ b/activerecord/lib/active_record/type/date_time.rb
@@ -2,6 +2,9 @@ module ActiveRecord
   module Type
     class DateTime < Value # :nodoc:
       include TimeValue
+      include Helpers::AcceptsMultiparameterTime.new(
+        defaults: { 4 => 0, 5 => 0 }
+      )
 
       def type
         :datetime
@@ -42,6 +45,14 @@ module ActiveRecord
 
         new_time(*time_hash.values_at(:year, :mon, :mday, :hour, :min, :sec, :sec_fraction, :offset))
       end
+
+      def value_from_multiparameter_assignment(values_hash)
+        missing_parameter = (1..3).detect { |key| !values_hash.key?(key) }
+        if missing_parameter
+          raise ArgumentError, missing_parameter
+        end
+        super
+      end
     end
   end
 end