Add `exists?` and `update_all` to `CollectionProxy` for respects an association scope

Fixes #25732.

2 files changed, 21 insertions, 5 deletions

diff --git a/activerecord/lib/active_record/associations/collection_proxy.rb b/activerecord/lib/active_record/associations/collection_proxy.rb
index 17ccf5a86c..db3037d8f9 100644
--- a/activerecord/lib/active_record/associations/collection_proxy.rb
+++ b/activerecord/lib/active_record/associations/collection_proxy.rb
@@ -29,7 +29,7 @@ module ActiveRecord
     # instantiation of the actual post records.
     class CollectionProxy < Relation
       delegate(*(ActiveRecord::Calculations.public_instance_methods - [:count]), to: :scope)
-      delegate :find_nth, to: :scope
+      delegate :find_nth, :exists?, :update_all, :arel, to: :scope
 
       def initialize(klass, association) #:nodoc:
         @association = association
@@ -897,10 +897,6 @@ module ActiveRecord
         !!@association.include?(record)
       end
 
-      def arel #:nodoc:
-        scope.arel
-      end
-
       def proxy_association
         @association
       end
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 61a5c2c3b7..325a06d724 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -439,6 +439,26 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
     assert_equal person, person.readers.first.person
   end
 
+  def test_update_all_respects_association_scope
+    person = Person.new
+    person.first_name = 'Naruto'
+    person.references << Reference.new
+    person.id = 10
+    person.references
+    person.save!
+    assert_equal 1, person.references.update_all(favourite: true)
+  end
+
+  def test_exists_respects_association_scope
+    person = Person.new
+    person.first_name = 'Sasuke'
+    person.references << Reference.new
+    person.id = 10
+    person.references
+    person.save!
+    assert_predicate person.references, :exists?
+  end
+
   def force_signal37_to_load_all_clients_of_firm
     companies(:first_firm).clients_of_firm.each {|f| }
   end