1 files changed, 20 insertions, 10 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
index 87593ef704..e1a75f8e5e 100644
--- a/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
+++ b/activerecord/lib/active_record/connection_adapters/postgresql/oid/array.rb
@@ -5,10 +5,12 @@ module ActiveRecord
         class Array < Type::Value # :nodoc:
           include Type::Helpers::Mutable
 
+          Data = Struct.new(:encoder, :values) # :nodoc:
+
           attr_reader :subtype, :delimiter
-          delegate :type, :user_input_in_time_zone, :limit, to: :subtype
+          delegate :type, :user_input_in_time_zone, :limit, :precision, :scale, to: :subtype
 
-          def initialize(subtype, delimiter = ',')
+          def initialize(subtype, delimiter = ",")
             @subtype = subtype
             @delimiter = delimiter
 
@@ -17,8 +19,11 @@ module ActiveRecord
           end
 
           def deserialize(value)
-            if value.is_a?(::String)
+            case value
+            when ::String
               type_cast_array(@pg_decoder.decode(value), :deserialize)
+            when Data
+              deserialize(value.values)
             else
               super
             end
@@ -33,7 +38,8 @@ module ActiveRecord
 
           def serialize(value)
             if value.is_a?(::Array)
-              @pg_encoder.encode(type_cast_array(value, :serialize))
+              casted_values = type_cast_array(value, :serialize)
+              Data.new(@pg_encoder, casted_values)
             else
               super
             end
@@ -54,15 +60,19 @@ module ActiveRecord
             value.map(&block)
           end
 
+          def changed_in_place?(raw_old_value, new_value)
+            deserialize(raw_old_value) != new_value
+          end
+
           private
 
-          def type_cast_array(value, method)
-            if value.is_a?(::Array)
-              value.map { |item| type_cast_array(item, method) }
-            else
-              @subtype.public_send(method, value)
+            def type_cast_array(value, method)
+              if value.is_a?(::Array)
+                value.map { |item| type_cast_array(item, method) }
+              else
+                @subtype.public_send(method, value)
+              end
             end
-          end
         end
       end
     end