`SetupAndTeardown` has few caveats that breaks libraries:

- In #32472 I introduced a fix in order for all `after_teardown` method provided by libraries and Rails to run, even if the application's `teardown` method raised an error (That's the default minitest behavior). However this change wasn't enough and doesn't take in consideration the ancestors chain.
  If a library's module containing an `after_teardown` method get included after the `SetupAndTeardown` module (one example is the [ActiveRecord::TestFixtures module](https://github.com/rails/rails/blob/7d2400ab61c8e3ed95e14d03ba3844e8ba2e36e4/activerecord/lib/active_record/fixtures.rb#L855-L856), then the ancestors of the test class would look something like
  ```ruby
    class MyTest < ActiveSupport::TestCase
    end

    puts MyTest.ancestors # [MyTest, ActiveSupport::TestCase, ActiveRecord::TestFixtures, ActiveSupport::Testing::SetupAndTeardown]
  ```
  Any class/module in the ancestors chain that are **before** the `ActiveSupport::Testing::SetupAndTeardown` will behave incorrectly:
    - Their `before_setup` method will get called **after** all regular setup method
    - Their `after_teardown` method won't even get called in case an exception is raised inside a regular's test `teardown`

  A simple reproduction script of the problem here https://gist.github.com/Edouard-chin/70705542a59a8593f619b02e1c0a188c

- One solution to this problem is to have the `AS::SetupAndTeardown` module be the very first in the ancestors chain. By doing that we ensure that no `before_setup` / `after_teardown` get executed prior to running the teardown callbacks

1 files changed, 5 insertions, 3 deletions

diff --git a/activesupport/test/testing/after_teardown_test.rb b/activesupport/test/testing/after_teardown_test.rb
index 68c368909c..961af49479 100644
--- a/activesupport/test/testing/after_teardown_test.rb
+++ b/activesupport/test/testing/after_teardown_test.rb
@@ -4,13 +4,14 @@ require "abstract_unit"
 
 module OtherAfterTeardown
   def after_teardown
+    super
+
     @witness = true
   end
 end
 
-class AfterTeardownTest < Minitest::Test
+class AfterTeardownTest < ActiveSupport::TestCase
   include OtherAfterTeardown
-  include ActiveSupport::Testing::SetupAndTeardown
 
   attr_writer :witness
 
@@ -21,11 +22,12 @@ class AfterTeardownTest < Minitest::Test
   end
 
   def after_teardown
-    assert_raises MyError do
+    assert_changes -> { failures.count }, from: 0, to: 1 do
       super
     end
 
     assert_equal true, @witness
+    failures.clear
   end
 
   def test_teardown_raise_but_all_after_teardown_method_are_called