Relation no longer respond to Arel methods

This follows up d97980a16d76ad190042b4d8578109714e9c53d0.

3 files changed, 8 insertions, 19 deletions

diff --git a/activerecord/lib/active_record/relation/delegation.rb b/activerecord/lib/active_record/relation/delegation.rb
index 6e8a1fcad4..f7c3b3783f 100644
--- a/activerecord/lib/active_record/relation/delegation.rb
+++ b/activerecord/lib/active_record/relation/delegation.rb
@@ -132,7 +132,7 @@ module ActiveRecord
 
     private
       def respond_to_missing?(method, _)
-        super || @klass.respond_to?(method) || arel.respond_to?(method)
+        super || @klass.respond_to?(method)
       end
   end
 end
diff --git a/activerecord/test/cases/relation/delegation_test.rb b/activerecord/test/cases/relation/delegation_test.rb
index b600c999a6..63ae438de3 100644
--- a/activerecord/test/cases/relation/delegation_test.rb
+++ b/activerecord/test/cases/relation/delegation_test.rb
@@ -5,7 +5,7 @@ require "models/post"
 require "models/comment"
 
 module ActiveRecord
-  module ArrayDelegationTests
+  module DelegationTests
     ARRAY_DELEGATES = [
       :+, :-, :|, :&, :[], :shuffle,
       :all?, :collect, :compact, :detect, :each, :each_cons, :each_with_index,
@@ -21,10 +21,14 @@ module ActiveRecord
         assert_respond_to target, method
       end
     end
+
+    def test_not_respond_to_arel_method
+      assert_not_respond_to target, :exists
+    end
   end
 
   class DelegationAssociationTest < ActiveRecord::TestCase
-    include ArrayDelegationTests
+    include DelegationTests
 
     def target
       Post.new.comments
@@ -32,7 +36,7 @@ module ActiveRecord
   end
 
   class DelegationRelationTest < ActiveRecord::TestCase
-    include ArrayDelegationTests
+    include DelegationTests
 
     def target
       Comment.all
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 756eeca35f..6b5b877260 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -480,21 +480,6 @@ class RelationTest < ActiveRecord::TestCase
     assert_nothing_raised { Topic.reorder([]) }
   end
 
-  def test_respond_to_delegates_to_arel
-    relation = Topic.all
-    fake_arel = Struct.new(:responds) {
-      def respond_to?(method, access = false)
-        responds << [method, access]
-      end
-    }.new []
-
-    relation.extend(Module.new { attr_accessor :arel })
-    relation.arel = fake_arel
-
-    relation.respond_to?(:matching_attributes)
-    assert_equal [:matching_attributes, false], fake_arel.responds.first
-  end
-
   def test_respond_to_dynamic_finders
     relation = Topic.all