`scope` now raises on "dangerous" name conflicts

Similar to dangerous attribute methods, a scope name conflict is
dangerous if it conflicts with an existing class method defined within
`ActiveRecord::Base` but not its ancestors.

See also #13389.

*Godfrey Chan*, *Philippe Creux*

1 files changed, 6 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/scoping/named.rb b/activerecord/lib/active_record/scoping/named.rb
index 2a5718f388..49cadb66d0 100644
--- a/activerecord/lib/active_record/scoping/named.rb
+++ b/activerecord/lib/active_record/scoping/named.rb
@@ -139,6 +139,12 @@ module ActiveRecord
         #   Article.published.featured.latest_article
         #   Article.featured.titles
         def scope(name, body, &block)
+          if dangerous_class_method?(name)
+            raise ArgumentError, "You tried to define a scope named \"#{name}\" " \
+              "on the model \"#{self.name}\", but Active Record already defined " \
+              "a class method with the same name."
+          end
+
           extension = Module.new(&block) if block
 
           singleton_class.send(:define_method, name) do |*args|