Refine ActiveRecord::SerializeMatcher for Rails 7.1 compatibility

This commit refines the `ActiveRecord::SerializeMatcher` to
accommodate changes in the public API introduced in Rails 7.1.
The `serialize` method's API has been updated, necessitating
adjustments to our matcher specs to align with the new API.

While this PR addresses the immediate need for compatibility,
there is potential for further enhancements and refinements in
the matcher's implementation to bring it in line with the revised
public API. However, such improvements will be explored in a future PR.

For reference, the changes in the public API can be found in the following PR: rails/rails#47463

This commit adjusts the `ActiveRecord::SerializeMatcher` the public
API for the `serialize` method has changed on Rails 7.1, so we
had to

spec/support/unit/attribute.rb

@@ -3,7 +3,7 @@ class Attribute
     DEFAULT_COLUMN_TYPE = :string
     DEFAULT_COLUMN_OPTIONS = {
       null: false,
-      array: false
+      array: false,
     }.freeze
 
     def initialize(args)

spec/unit/shoulda/matchers/active_model/validate_presence_of_matcher_spec.rb

@@ -56,51 +56,102 @@
       expect(&assertion).to fail_with_message(message)
     end
 
-    context 'when the attribute is decorated with serialize' do
-      context 'and the serializer is a built-in Ruby type' do
-        context 'and the type is a string' do
+    if rails_version >= '7.1.0'
+      context 'when the attribute is decorated with serialize' do
+        context 'and the serializer is a built-in Ruby type' do
+          context 'and the type is a string' do
+            it 'still works' do
+              record = record_validating_presence_of(:traits) do
+                serialize :traits, type: String, coder: YAML
+              end
+
+              expect(record).to validate_presence_of(:traits)
+            end
+          end
+
+          context 'and the type is not a string' do
+            it 'still works' do
+              record = record_validating_presence_of(:traits) do
+                serialize :traits, type: Array, coder: YAML
+              end
+
+              expect(record).to validate_presence_of(:traits)
+            end
+          end
+        end
+
+        context 'and the serializer is JSON' do
           it 'still works' do
             record = record_validating_presence_of(:traits) do
-              serialize :traits, String
+              serialize :traits, coder: JSON
             end
 
             expect(record).to validate_presence_of(:traits)
           end
         end
 
-        context 'and the type is not a string' do
+        context 'and the serializer is something custom' do
           it 'still works' do
-            record = record_validating_presence_of(:traits) do
-              serialize :traits, Array
+            serializer = Class.new do
+              define_singleton_method(:dump) { |value| value }
+              define_singleton_method(:load) { |value| value }
             end
 
-            expect(record).to validate_presence_of(:traits)
+            record = record_validating_presence_of(:data) do
+              serialize :data, coder: serializer
+            end
+
+            expect(record).to validate_presence_of(:data)
           end
         end
       end
+    else
+      context 'when the attribute is decorated with serialize' do
+        context 'and the serializer is a built-in Ruby type' do
+          context 'and the type is a string' do
+            it 'still works' do
+              record = record_validating_presence_of(:traits) do
+                serialize :traits, String
+              end
 
-      context 'and the serializer is JSON' do
-        it 'still works' do
-          record = record_validating_presence_of(:traits) do
-            serialize :traits, JSON
+              expect(record).to validate_presence_of(:traits)
+            end
           end
 
-          expect(record).to validate_presence_of(:traits)
-        end
-      end
+          context 'and the type is not a string' do
+            it 'still works' do
+              record = record_validating_presence_of(:traits) do
+                serialize :traits, Array
+              end
 
-      context 'and the serializer is something custom' do
-        it 'still works' do
-          serializer = Class.new do
-            define_singleton_method(:dump) { |value| value }
-            define_singleton_method(:load) { |value| value }
+              expect(record).to validate_presence_of(:traits)
+            end
           end
+        end
+
+        context 'and the serializer is JSON' do
+          it 'still works' do
+            record = record_validating_presence_of(:traits) do
+              serialize :traits, JSON
+            end
 
-          record = record_validating_presence_of(:data) do
-            serialize :data, serializer
+            expect(record).to validate_presence_of(:traits)
           end
+        end
+
+        context 'and the serializer is something custom' do
+          it 'still works' do
+            serializer = Class.new do
+              define_singleton_method(:dump) { |value| value }
+              define_singleton_method(:load) { |value| value }
+            end
+
+            record = record_validating_presence_of(:data) do
+              serialize :data, serializer
+            end
 
-          expect(record).to validate_presence_of(:data)
+            expect(record).to validate_presence_of(:data)
+          end
         end
       end
     end

spec/unit/shoulda/matchers/active_record/serialize_matcher_spec.rb

@@ -41,38 +41,40 @@ def unserialized_model
 
   context 'an attribute that will end up being serialized as YAML' do
     it 'accepts when the types match' do
-      expect(with_serialized_attr(Hash)).to serialize(:attr).as(Hash)
+      expect(with_serialized_attr(type: Hash, coder: JSON)).to serialize(:attr).as(Hash)
     end
 
     it 'rejects when the types do not match' do
-      expect(with_serialized_attr(Hash)).not_to serialize(:attr).as(String)
+      expect(with_serialized_attr(type: Hash)).not_to serialize(:attr).as(String)
     end
 
     it 'rejects when using as_instance_of' do
-      expect(with_serialized_attr(Hash)).not_to serialize(:attr).as_instance_of(Hash)
+      expect(with_serialized_attr(type: Hash)).not_to serialize(:attr).as_instance_of(Hash)
     end
   end
 
   context 'a serializer that is an instance of a class' do
     it 'accepts when using #as_instance_of' do
       define_serializer(:ExampleSerializer)
-      expect(with_serialized_attr(ExampleSerializer.new)).
+      expect(with_serialized_attr(coder: ExampleSerializer.new)).
         to serialize(:attr).as_instance_of(ExampleSerializer)
     end
 
     it 'rejects when using #as' do
       define_serializer(:ExampleSerializer)
-      expect(with_serialized_attr(ExampleSerializer.new)).
+      expect(with_serialized_attr(coder: ExampleSerializer.new)).
         not_to serialize(:attr).as(ExampleSerializer)
     end
   end
 
-  def with_serialized_attr(type = nil)
+  def with_serialized_attr(type: nil, coder: YAML)
+    type_or_coder = rails_version >= '7.1.0' ? nil : type || coder
+
     define_model(:example, attr: :string) do
       if type
-        serialize :attr, type
+        serialize :attr, type_or_coder, type: type, coder: coder
       else
-        serialize :attr
+        serialize :attr, type_or_coder, coder: coder
       end
     end.new
   end