Remove deprecated `ActionDispatch::Response#to_ary`

actionpack/CHANGELOG.md

+*   Remove deprecated `ActionDispatch::Response#to_ary`.
+
+    *Rafael Mendonça França*
+
 *   Remove deprecated `ActionDispatch::Request#deep_munge`.
 
     *Rafael Mendonça França*

actionpack/lib/action_dispatch/http/response.rb

 require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/string/filters'
-require 'active_support/deprecation'
 require 'action_dispatch/http/filter_redirect'
 require 'monitor'
 
@@ -284,20 +283,6 @@ def to_a
     end
     alias prepare! to_a
 
-    # Be super clear that a response object is not an Array. Defining this
-    # would make implicit splatting work, but it also makes adding responses
-    # as arrays work, and "flattening" responses, cascading to the rack body!
-    # Not sensible behavior.
-    def to_ary
-      ActiveSupport::Deprecation.warn(<<-MSG.squish)
-        `ActionDispatch::Response#to_ary` no longer performs implicit conversion
-        to an array. Please use `response.to_a` instead, or a splat like `status,
-        headers, body = *response`.
-      MSG
-
-      to_a
-    end
-
     # Returns the response cookies, converted to a Hash of (name => value) pairs
     #
     #   assert_equal 'AuthorOfNewPage', r.cookies['author']

actionpack/test/dispatch/response_test.rb

@@ -231,9 +231,9 @@ def test_response_body_encoding
     assert_equal ['Not Found'], body.each.to_a
   end
 
-  test "[response].flatten does not recurse infinitely" do
+  test "[response.to_a].flatten does not recurse infinitely" do
     Timeout.timeout(1) do # use a timeout to prevent it stalling indefinitely
-      status, headers, body = assert_deprecated { [@response].flatten }
+      status, headers, body = [@response.to_a].flatten
       assert_equal @response.status, status
       assert_equal @response.headers, headers
       assert_equal @response.body, body.each.to_a.join
@@ -251,20 +251,6 @@ def test_response_body_encoding
     status, headers, body = Rack::ContentLength.new(app).call(env)
     assert_equal '5', headers['Content-Length']
   end
-
-  test "implicit destructuring and Array conversion is deprecated" do
-    response = ActionDispatch::Response.new(404, { 'Content-Type' => 'text/plain' }, ['Not Found'])
-
-    assert_deprecated do
-      status, headers, body = response
-
-      assert_equal 404, status
-      assert_equal({ 'Content-Type' => 'text/plain' }, headers)
-      assert_equal ['Not Found'], body.each.to_a
-    end
-
-    assert_deprecated { response.to_ary }
-  end
 end
 
 class ResponseIntegrationTest < ActionDispatch::IntegrationTest