Remove deprecated support to YAML load ActiveRecord::Base instance in the Rails 4.2 and 4.1 formats

Author: rafaelfranca

activerecord/CHANGELOG.md

@@ -1,3 +1,7 @@
+*   Remove deprecated support to YAML load `ActiveRecord::Base` instance in the Rails 4.2 and 4.1 formats.
+
+    *Rafael Mendonça França*
+
 *   Remove deprecated option `:spec_name` in the `configs_for` method.
 
     *Rafael Mendonça França*

activerecord/lib/active_record/core.rb

@@ -489,7 +489,7 @@ def initialize(attributes = nil)
     #   post.init_with(coder)
     #   post.title # => 'hello world'
     def init_with(coder, &block)
-      coder = LegacyYamlAdapter.convert(self.class, coder)
+      coder = LegacyYamlAdapter.convert(coder)
       attributes = self.class.yaml_encoder.decode(coder)
       init_with_attributes(attributes, coder["new_record"], &block)
     end

activerecord/lib/active_record/legacy_yaml_adapter.rb

@@ -2,50 +2,13 @@
 
 module ActiveRecord
   module LegacyYamlAdapter # :nodoc:
-    def self.convert(klass, coder)
+    def self.convert(coder)
       return coder unless coder.is_a?(Psych::Coder)
 
       case coder["active_record_yaml_version"]
       when 1, 2 then coder
       else
-        ActiveSupport::Deprecation.warn(<<-MSG.squish)
-          YAML loading from legacy format older than Rails 5.0 is deprecated
-          and will be removed in Rails 7.0.
-        MSG
-        if coder["attributes"].is_a?(ActiveModel::AttributeSet)
-          Rails420.convert(klass, coder)
-        else
-          Rails41.convert(klass, coder)
-        end
-      end
-    end
-
-    module Rails420 # :nodoc:
-      def self.convert(klass, coder)
-        attribute_set = coder["attributes"]
-
-        klass.attribute_names.each do |attr_name|
-          attribute = attribute_set[attr_name]
-          if attribute.type.is_a?(Delegator)
-            type_from_klass = klass.type_for_attribute(attr_name)
-            attribute_set[attr_name] = attribute.with_type(type_from_klass)
-          end
-        end
-
-        coder
-      end
-    end
-
-    module Rails41 # :nodoc:
-      def self.convert(klass, coder)
-        attributes = klass.attributes_builder
-          .build_from_database(coder["attributes"])
-        new_record = coder["attributes"][klass.primary_key].blank?
-
-        {
-          "attributes" => attributes,
-          "new_record" => new_record,
-        }
+        raise("Active Record doesn't know how to load YAML with this format.")
       end
     end
   end

activerecord/test/cases/yaml_serialization_test.rb

@@ -112,25 +112,19 @@ def test_deserializing_rails_v1_mysql_yaml
   end
 
   def test_deserializing_rails_41_yaml
-    topic = assert_deprecated do
+    error = assert_raises(RuntimeError) do
       yaml_load(yaml_fixture("rails_4_1"))
     end
 
-    assert_predicate topic, :new_record?
-    assert_nil topic.id
-    assert_equal "The First Topic", topic.title
-    assert_equal({ omg: :lol }, topic.content)
+    assert_equal "Active Record doesn't know how to load YAML with this format.", error.message
   end
 
   def test_deserializing_rails_4_2_0_yaml
-    topic = assert_deprecated do
+    error = assert_raises(RuntimeError) do
       yaml_load(yaml_fixture("rails_4_2_0"))
     end
 
-    assert_not_predicate topic, :new_record?
-    assert_equal 1, topic.id
-    assert_equal "The First Topic", topic.title
-    assert_equal("Have a nice day", topic.content)
+    assert_equal "Active Record doesn't know how to load YAML with this format.", error.message
   end
 
   def test_yaml_encoding_keeps_mutations

guides/source/7_0_release_notes.md

@@ -104,6 +104,8 @@ Please refer to the [Changelog][active-record] for detailed changes.
 
 *   Remove deprecated option `:spec_name` in the `configs_for` method.
 
+*   Remove deprecated support to YAML load `ActiveRecord::Base` instance in the Rails 4.2 and 4.1 formats.
+
 ### Deprecations
 
 ### Notable changes