Generate delegation methods to named scope in the definition time

The delegation methods to named scope are defined when `method_missing`
is invoked on the relation.

Since #29301, the receiver in the named scope is changed to the relation
like others (e.g. `default_scope`, etc) for consistency.

Most named scopes would be delegated from relation by `method_missing`,
since we don't allow scopes to be defined which conflict with instance
methods on `Relation` (#31179). But if a named scope is defined with the
same name as any method on the `superclass` (e.g. `Kernel.open`), the
`method_missing` on the relation is not invoked.

To address the issue, make the delegation methods to named scope is
generated in the definition time.

Fixes #34098.

2 files changed, 11 insertions, 0 deletions

diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index eb65f9e74f..2d16815da8 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -2391,6 +2391,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   def test_collection_association_with_private_kernel_method
     firm = companies(:first_firm)
     assert_equal [accounts(:signals37)], firm.accounts.open
+    assert_equal [accounts(:signals37)], firm.accounts.available
   end
 
   def test_association_with_or_doesnt_set_inverse_instance_key
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 9914a61033..e471ee8039 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -1812,6 +1812,16 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal "Thank you for the welcome,Thank you again for the welcome", Post.first.comments.join(",")
   end
 
+  def test_relation_with_private_kernel_method
+    accounts = Account.all
+    assert_equal [accounts(:signals37)], accounts.open
+    assert_equal [accounts(:signals37)], accounts.available
+
+    sub_accounts = SubAccount.all
+    assert_equal [accounts(:signals37)], sub_accounts.open
+    assert_equal [accounts(:signals37)], sub_accounts.available
+  end
+
   test "#skip_query_cache!" do
     Post.cache do
       assert_queries(1) do