1 files changed, 93 insertions, 0 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
new file mode 100644
index 0000000000..622e00fffb
--- /dev/null
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_dumper.rb
@@ -0,0 +1,93 @@
+# frozen_string_literal: true
+
+module ActiveRecord
+  module ConnectionAdapters # :nodoc:
+    class SchemaDumper < SchemaDumper # :nodoc:
+      def self.create(connection, options)
+        new(connection, options)
+      end
+
+      private
+        def column_spec(column)
+          [schema_type_with_virtual(column), prepare_column_options(column)]
+        end
+
+        def column_spec_for_primary_key(column)
+          return {} if default_primary_key?(column)
+          spec = { id: schema_type(column).inspect }
+          spec.merge!(prepare_column_options(column).except!(:null))
+          spec[:default] ||= "nil" if explicit_primary_key_default?(column)
+          spec
+        end
+
+        def prepare_column_options(column)
+          spec = {}
+          spec[:limit] = schema_limit(column)
+          spec[:precision] = schema_precision(column)
+          spec[:scale] = schema_scale(column)
+          spec[:default] = schema_default(column)
+          spec[:null] = "false" unless column.null
+          spec[:collation] = schema_collation(column)
+          spec[:comment] = column.comment.inspect if column.comment.present?
+          spec.compact!
+          spec
+        end
+
+        def default_primary_key?(column)
+          schema_type(column) == :bigint
+        end
+
+        def explicit_primary_key_default?(column)
+          false
+        end
+
+        def schema_type_with_virtual(column)
+          if @connection.supports_virtual_columns? && column.virtual?
+            :virtual
+          else
+            schema_type(column)
+          end
+        end
+
+        def schema_type(column)
+          if column.bigint?
+            :bigint
+          else
+            column.type
+          end
+        end
+
+        def schema_limit(column)
+          limit = column.limit unless column.bigint?
+          limit.inspect if limit && limit != @connection.native_database_types[column.type][:limit]
+        end
+
+        def schema_precision(column)
+          column.precision.inspect if column.precision
+        end
+
+        def schema_scale(column)
+          column.scale.inspect if column.scale
+        end
+
+        def schema_default(column)
+          return unless column.has_default?
+          type = @connection.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