1 files changed, 48 insertions, 35 deletions
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
index b944a8631c..b912d24626 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -7,25 +7,20 @@ module ActiveRecord
     # Adapter level by over-writing this code inside the database specific adapters
     module ColumnDumper
       def column_spec(column)
-        spec = prepare_column_options(column)
-        (spec.keys - [:name, :type]).each{ |k| spec[k].insert(0, "#{k}: ")}
-        spec
+        [schema_type(column), prepare_column_options(column)]
       end
 
       def column_spec_for_primary_key(column)
-        return if column.type == :integer
-        spec = { id: column.type.inspect }
-        spec.merge!(prepare_column_options(column).delete_if { |key, _| [:name, :type].include?(key) })
+        return {} if default_primary_key?(column)
+        spec = { id: schema_type(column).inspect }
+        spec.merge!(prepare_column_options(column).except!(:null))
       end
 
-      # This can be overridden on a Adapter level basis to support other
+      # This can be overridden on an Adapter level basis to support other
       # extended datatypes (Example: Adding an array option in the
-      # PostgreSQLAdapter)
+      # PostgreSQL::ColumnDumper)
       def prepare_column_options(column)
         spec = {}
-        spec[:name]      = column.name.inspect
-        spec[:type]      = schema_type(column)
-        spec[:null]      = 'false' unless column.null
 
         if limit = schema_limit(column)
           spec[:limit] = limit
@@ -40,50 +35,68 @@ module ActiveRecord
         end
 
         default = schema_default(column) if column.has_default?
-        spec[:default]   = default unless default.nil?
+        spec[:default] = default unless default.nil?
+
+        spec[:null] = "false" unless column.null
 
         if collation = schema_collation(column)
           spec[:collation] = collation
         end
 
+        spec[:comment] = column.comment.inspect if column.comment.present?
+
         spec
       end
 
       # Lists the valid migration options
       def migration_keys
-        [:name, :limit, :precision, :scale, :default, :null, :collation]
+        [:limit, :precision, :scale, :default, :null, :collation, :comment]
       end
 
       private
 
-      def schema_type(column)
-        column.type.to_s
-      end
+        def default_primary_key?(column)
+          schema_type(column) == :bigint
+        end
 
-      def schema_limit(column)
-        limit = column.limit || native_database_types[column.type][:limit]
-        limit.inspect if limit
-      end
+        def schema_type(column)
+          if column.bigint?
+            :bigint
+          else
+            column.type
+          end
+        end
 
-      def schema_precision(column)
-        column.precision.inspect if column.precision
-      end
+        def schema_limit(column)
+          limit = column.limit unless column.bigint?
+          limit.inspect if limit && limit != native_database_types[column.type][:limit]
+        end
 
-      def schema_scale(column)
-        column.scale.inspect if column.scale
-      end
+        def schema_precision(column)
+          column.precision.inspect if column.precision
+        end
 
-      def schema_default(column)
-        type = lookup_cast_type_from_column(column)
-        default = type.deserialize(column.default)
-        unless default.nil?
-          type.type_cast_for_schema(default)
+        def schema_scale(column)
+          column.scale.inspect if column.scale
         end
-      end
 
-      def schema_collation(column)
-        column.collation.inspect if column.collation
-      end
+        def schema_default(column)
+          type = lookup_cast_type_from_column(column)
+          default = type.deserialize(column.default)
+          if default.nil?
+            schema_expression(column)
+          else
+            type.type_cast_for_schema(default)
+          end
+        end
+
+        def schema_expression(column)
+          "-> { #{column.default_function.inspect} }" if column.default_function
+        end
+
+        def schema_collation(column)
+          column.collation.inspect if column.collation
+        end
     end
   end
 end