Merge pull request rails#54683 from byroot/column-default-deserialize

Don't deserialize mutable defaults

Author: byroot

activerecord/lib/active_record/attributes.rb

@@ -244,10 +244,7 @@ def _default_attributes # :nodoc:
           # TODO: Remove the need for a connection after we release 8.1.
           attributes_hash = with_connection do |connection|
             columns_hash.transform_values do |column|
-              type = type_for_column(connection, column)
-              default = column.default
-              default = type.deserialize(default) unless default.nil?
-              ActiveModel::Attribute.from_database(column.name, default, type)
+              ActiveModel::Attribute.from_database(column.name, column.default, type_for_column(connection, column))
             end
           end
 

activerecord/lib/active_record/connection_adapters/column.rb

@@ -22,7 +22,7 @@ def initialize(name, cast_type, default, sql_type_metadata = nil, null = true, d
         @cast_type = cast_type
         @sql_type_metadata = sql_type_metadata
         @null = null
-        @default = default
+        @default = default.nil? || cast_type.mutable? ? default : cast_type.deserialize(default)
         @default_function = default_function
         @collation = collation
         @comment = comment
@@ -117,7 +117,7 @@ def virtual?
         def deduplicated
           @name = -name
           @sql_type_metadata = sql_type_metadata.deduplicate if sql_type_metadata
-          @default = -default if default
+          @default = -default if String === default
           @default_function = -default_function if default_function
           @collation = -collation if collation
           @comment = -comment if comment

activerecord/test/cases/adapters/postgresql/geometric_test.rb

@@ -131,11 +131,11 @@ def test_legacy_column
   end
 
   def test_legacy_default
-    assert_equal ActiveRecord::Point.new(12.2, 13.3), PostgresqlPoint.column_defaults["legacy_y"]
-    assert_equal ActiveRecord::Point.new(12.2, 13.3), PostgresqlPoint.new.legacy_y
+    assert_equal [12.2, 13.3], PostgresqlPoint.column_defaults["legacy_y"]
+    assert_equal [12.2, 13.3], PostgresqlPoint.new.legacy_y
 
-    assert_equal ActiveRecord::Point.new(14.4, 15.5), PostgresqlPoint.column_defaults["legacy_z"]
-    assert_equal ActiveRecord::Point.new(14.4, 15.5), PostgresqlPoint.new.legacy_z
+    assert_equal [14.4, 15.5], PostgresqlPoint.column_defaults["legacy_z"]
+    assert_equal [14.4, 15.5], PostgresqlPoint.new.legacy_z
   end
 
   def test_legacy_schema_dumping

activerecord/test/cases/adapters/postgresql/json_test.rb

@@ -10,6 +10,7 @@ def setup
     super
     @connection.create_table("json_data_type") do |t|
       t.public_send column_type, "payload", default: {} # t.json 'payload', default: {}
+      t.public_send column_type, "with_defaults", default: { list: [] }
       t.public_send column_type, "settings"             # t.json 'settings'
       t.public_send column_type, "objects", array: true # t.json 'objects', array: true
     end
@@ -25,6 +26,10 @@ def test_default
     assert_equal({ "users" => "read", "posts" => ["read", "write"] }, klass.new.permissions)
   end
 
+  def test_default_before_type_cast
+    assert_equal '{"list":[]}', klass.new.with_defaults_before_type_cast.gsub(" ", "")
+  end
+
   def test_deserialize_with_array
     x = klass.new(objects: ["foo" => "bar"])
     assert_equal ["foo" => "bar"], x.objects

activerecord/test/cases/adapters/sqlite3/json_test.rb

@@ -10,6 +10,7 @@ def setup
     super
     @connection.create_table("json_data_type") do |t|
       t.json "payload", default: {}
+      t.json "with_defaults", default: { list: [] }
       t.json "settings"
     end
   end
@@ -22,6 +23,10 @@ def test_default
     assert_equal({ "users" => "read", "posts" => ["read", "write"] }, klass.new.permissions)
   end
 
+  def test_default_before_type_cast
+    assert_equal '{"list":[]}', klass.new.with_defaults_before_type_cast
+  end
+
   private
     def column_type
       :json

activerecord/test/cases/adapters/sqlite3/sqlite3_adapter_test.rb

@@ -636,7 +636,7 @@ def test_columns_with_default
           column = @conn.columns("ex").find { |x|
             x.name == "number"
           }
-          assert_equal "10", column.default
+          assert_equal 10, column.default
         end
       end
 

activerecord/test/cases/migration/change_schema_test.rb

@@ -72,7 +72,7 @@ def test_create_table_with_defaults
         assert_equal "hello", one.default
         assert_equal true, two.fetch_cast_type(connection).deserialize(two.default)
         assert_equal false, three.fetch_cast_type(connection).deserialize(three.default)
-        assert_equal "1", four.default
+        assert_equal 1, four.default
         assert_equal "hello", five.default unless mysql
       end
 

activerecord/test/cases/migration/columns_test.rb

@@ -55,13 +55,13 @@ def test_rename_column_preserves_default_value_not_null
         add_column "test_models", "salary", :integer, default: 70000
 
         default_before = connection.columns("test_models").find { |c| c.name == "salary" }.default
-        assert_equal "70000", default_before
+        assert_equal 70000, default_before
 
         rename_column "test_models", "salary", "annual_salary"
 
         assert_includes TestModel.column_names, "annual_salary"
         default_after = connection.columns("test_models").find { |c| c.name == "annual_salary" }.default
-        assert_equal "70000", default_after
+        assert_equal 70000, default_after
       end
 
       if current_adapter?(:Mysql2Adapter, :TrilogyAdapter)

activerecord/test/cases/migration_test.rb

@@ -1254,7 +1254,7 @@ def test_adding_multiple_columns
 
       assert_equal 8, columns.size
       [:name, :qualification, :experience].each { |s| assert_equal :string, column(s).type }
-      assert_equal "0", column(:age).default
+      assert_equal 0, column(:age).default
       assert_equal "This is a comment", column(:birthdate).comment
     end