Allow included modules to override association methods.

Closes #16684.

This is achieved by always generating `GeneratedAssociationMethods` when
`ActiveRecord::Base` is subclassed. When some of the included modules
of `ActiveRecord::Base` were reordered this behavior was broken as
`Core#initialize_generated_modules` was no longer called. Meaning that
the module was generated on first access.

5 files changed, 23 insertions, 2 deletions

diff --git a/activerecord/CHANGELOG.md b/activerecord/CHANGELOG.md
index 001338b46c..9ff2e2bb56 100644
--- a/activerecord/CHANGELOG.md
+++ b/activerecord/CHANGELOG.md
@@ -1,3 +1,9 @@
+*   Allow included modules to override association methods.
+
+    Fixes #16684.
+
+    *Yves Senn*
+
 *   Schema loading rake tasks (like `db:schema:load` and `db:setup`) maintain
     the database connection to the current environment.
 
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 43a3993898..36d0d63c71 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -69,6 +69,8 @@ module ActiveRecord
         @generated_attribute_methods = GeneratedAttributeMethods.new { extend Mutex_m }
         @attribute_methods_generated = false
         include @generated_attribute_methods
+
+        super
       end
 
       # Generates all the attribute related methods for columns in the database
diff --git a/activerecord/lib/active_record/core.rb b/activerecord/lib/active_record/core.rb
index 2e9c9e3197..83859e474a 100644
--- a/activerecord/lib/active_record/core.rb
+++ b/activerecord/lib/active_record/core.rb
@@ -183,8 +183,6 @@ module ActiveRecord
       end
 
       def initialize_generated_modules
-        super
-
         generated_association_methods
       end
 
diff --git a/activerecord/test/cases/associations_test.rb b/activerecord/test/cases/associations_test.rb
index 635c657d9b..9b0cf4c18f 100644
--- a/activerecord/test/cases/associations_test.rb
+++ b/activerecord/test/cases/associations_test.rb
@@ -357,4 +357,18 @@ class GeneratedMethodsTest < ActiveRecord::TestCase
   def test_model_method_overrides_association_method
     assert_equal(comments(:greetings).body, posts(:welcome).first_comment)
   end
+
+  module MyModule
+    def comments; :none end
+  end
+
+  class MyArticle < ActiveRecord::Base
+    self.table_name = "articles"
+    include MyModule
+    has_many :comments, inverse_of: false
+  end
+
+  def test_included_module_overwrites_association_methods
+    assert_equal :none, MyArticle.new.comments
+  end
 end
diff --git a/activerecord/test/cases/attribute_methods/read_test.rb b/activerecord/test/cases/attribute_methods/read_test.rb
index 4741ee8799..e38b32d7fc 100644
--- a/activerecord/test/cases/attribute_methods/read_test.rb
+++ b/activerecord/test/cases/attribute_methods/read_test.rb
@@ -13,6 +13,7 @@ module ActiveRecord
           def self.superclass; Base; end
           def self.base_class; self; end
           def self.decorate_matching_attribute_types(*); end
+          def self.initialize_generated_modules; end
 
           include ActiveRecord::AttributeMethods