Merge pull request rails#49173 from Shopify/define-alias-attribute-methods-in-define_attribute_methods

Define alias attribute methods in `define_attribute_methods`

Author: byroot

activemodel/lib/active_model/attribute_methods.rb

@@ -202,8 +202,10 @@ def attribute_method_affix(*affixes)
       #   person.name_short?     # => true
       #   person.nickname_short? # => true
       def alias_attribute(new_name, old_name)
-        self.attribute_aliases = attribute_aliases.merge(new_name.to_s => old_name.to_s)
-        self.local_attribute_aliases = local_attribute_aliases.merge(new_name.to_s => old_name.to_s)
+        old_name = old_name.to_s
+        new_name = new_name.to_s
+        self.attribute_aliases = attribute_aliases.merge(new_name => old_name)
+        aliases_by_attribute_name[old_name] << new_name
         eagerly_generate_alias_attribute_methods(new_name, old_name)
       end
 
@@ -282,7 +284,12 @@ def attribute_alias(name)
       #   end
       def define_attribute_methods(*attr_names)
         ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |owner|
-          attr_names.flatten.each { |attr_name| define_attribute_method(attr_name, _owner: owner) }
+          attr_names.flatten.each do |attr_name|
+            define_attribute_method(attr_name, _owner: owner)
+            aliases_by_attribute_name[attr_name.to_s].each do |aliased_name|
+              generate_alias_attribute_methods owner, aliased_name, attr_name
+            end
+          end
         end
       end
 
@@ -365,13 +372,11 @@ def undefine_attribute_methods
         attribute_method_patterns_cache.clear
       end
 
-      def local_attribute_aliases # :nodoc:
-        @local_attribute_aliases ||= {}
+      def aliases_by_attribute_name # :nodoc:
+        @aliases_by_attribute_name ||= Hash.new { |h, k| h[k] = [] }
       end
 
       private
-        attr_writer :local_attribute_aliases # :nodoc:
-
         def inherited(base) # :nodoc:
           super
           base.class_eval do

activemodel/test/cases/attribute_methods_test.rb

@@ -119,6 +119,34 @@ class AttributeMethodsTest < ActiveModel::TestCase
     ModelWithAttributes.undefine_attribute_methods
   end
 
+  test "#define_attribute_methods defines alias attribute methods after undefining" do
+    topic_class = Class.new do
+      include ActiveModel::AttributeMethods
+      define_attribute_methods :title
+      alias_attribute :aliased_title_to_be_redefined, :title
+
+      def attributes
+        { title: "Active Model Topic" }
+      end
+
+      private
+        def attribute(name)
+          attributes[name.to_sym]
+        end
+    end
+
+    topic = topic_class.new
+    assert_equal("Active Model Topic", topic.aliased_title_to_be_redefined)
+    topic_class.undefine_attribute_methods
+
+    assert_not_respond_to topic, :aliased_title_to_be_redefined
+
+    topic_class.define_attribute_methods :title
+
+    assert_respond_to topic, :aliased_title_to_be_redefined
+    assert_equal "Active Model Topic", topic.aliased_title_to_be_redefined
+  end
+
   test "#define_attribute_method does not generate attribute method if already defined in attribute module" do
     klass = Class.new(ModelWithAttributes)
     klass.send(:generated_attribute_methods).module_eval do

activerecord/lib/active_record/attribute_methods.rb

@@ -71,8 +71,10 @@ def generate_alias_attributes # :nodoc:
         generated_attribute_methods.synchronize do
           return if @alias_attributes_mass_generated
           ActiveSupport::CodeGenerator.batch(generated_attribute_methods, __FILE__, __LINE__) do |code_generator|
-            local_attribute_aliases.each do |new_name, old_name|
-              generate_alias_attribute_methods(code_generator, new_name, old_name)
+            aliases_by_attribute_name.each do |old_name, new_names|
+              new_names.each do |new_name|
+                generate_alias_attribute_methods(code_generator, new_name, old_name)
+              end
             end
           end
 

activerecord/test/cases/attribute_methods_test.rb

@@ -1039,6 +1039,25 @@ def name
     end
   end
 
+  test "#define_attribute_methods brings back undefined aliases" do
+    topic_class = Class.new(ActiveRecord::Base) do
+      self.table_name = "topics"
+
+      alias_attribute :title_alias_to_be_undefined, :title
+    end
+
+    topic = topic_class.new(title: "New topic")
+    assert_equal("New topic", topic.title_alias_to_be_undefined)
+    topic_class.undefine_attribute_methods
+
+    assert_not_respond_to topic, :title_alias_to_be_undefined
+
+    topic_class.define_attribute_methods
+
+    assert_respond_to topic, :title_alias_to_be_undefined
+    assert_equal "New topic", topic.title_alias_to_be_undefined
+  end
+
   test "define_attribute_method works with both symbol and string" do
     klass = Class.new(ActiveRecord::Base)
     klass.table_name = "foo"

activerecord/test/cases/validations/numericality_validation_test.rb

@@ -5,7 +5,6 @@
 
 class NumericalityValidationTest < ActiveRecord::TestCase
   def setup
-    NumericData.generate_alias_attributes
     @model_class = NumericData.dup
   end