AS::ArrayInquirer#respond_to_missing? should fallback to super

in case Array or any other ancestor class' respond_to_missing? was defined.

3 files changed, 20 insertions, 1 deletions

diff --git a/activesupport/CHANGELOG.md b/activesupport/CHANGELOG.md
index fb9f5a447c..aefc94e0d9 100644
--- a/activesupport/CHANGELOG.md
+++ b/activesupport/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Fixed a bug that `ArrayInquirer#respond_to_missing?` does not fallback to
+    `Array#respond_to_missing?`.
+
+    *Akira Matsuda*
+
 *   Fix inconsistent results when parsing large durations and constructing durations from code
 
         ActiveSupport::Duration.parse('P3Y') == 3.years # It should be true
diff --git a/activesupport/lib/active_support/array_inquirer.rb b/activesupport/lib/active_support/array_inquirer.rb
index 85122e39b2..d364996e0b 100644
--- a/activesupport/lib/active_support/array_inquirer.rb
+++ b/activesupport/lib/active_support/array_inquirer.rb
@@ -32,7 +32,7 @@ module ActiveSupport
 
     private
       def respond_to_missing?(name, include_private = false)
-        name[-1] == "?"
+        (name[-1] == "?") || super
       end
 
       def method_missing(name, *args)
diff --git a/activesupport/test/array_inquirer_test.rb b/activesupport/test/array_inquirer_test.rb
index 4d3f5b001c..3ed48dd49d 100644
--- a/activesupport/test/array_inquirer_test.rb
+++ b/activesupport/test/array_inquirer_test.rb
@@ -38,4 +38,18 @@ class ArrayInquirerTest < ActiveSupport::TestCase
     assert_instance_of ActiveSupport::ArrayInquirer, result
     assert_equal @array_inquirer, result
   end
+
+  def test_respond_to_fallback_to_array_respond_to
+    arr = ActiveSupport::ArrayInquirer.new([:x])
+    # This kind of emulates a situation that Array#respond_to_missing? is defined
+    arr.singleton_class.class_eval do
+      def respond_to_missing?(name, _include_private = false)
+        (name == :foo) || super
+      end
+    end
+
+    assert_respond_to arr, :can_you_hear_me?
+    assert_respond_to arr, :foo
+    assert_not_respond_to arr, :nope
+  end
 end