diff --git a/activesupport/Rakefile b/activesupport/Rakefile
index f10f19be0a..f48e3ac364 100644
--- a/activesupport/Rakefile
+++ b/activesupport/Rakefile
@@ -7,7 +7,6 @@ task default: :test
 task :package
 
 Rake::TestTask.new do |t|
-  t.libs << "test"
   t.pattern = "test/**/*_test.rb"
   t.warning = true
   t.verbose = true
@@ -21,7 +20,7 @@ end
 namespace :test do
   task :isolated do
     Dir.glob("test/**/*_test.rb").all? do |file|
-      sh(Gem.ruby, "-w", "-Ilib:test", file)
+      sh(Gem.ruby, "-w", file)
     end || raise("Failures")
   end
 
@@ -31,7 +30,6 @@ namespace :test do
         task("env:#{driver}") { ENV["REDIS_DRIVER"] = driver }
 
         Rake::TestTask.new(driver => "env:#{driver}") do |t|
-          t.libs << "test"
           t.test_files = ["test/cache/stores/redis_cache_store_test.rb"]
           t.warning = true
           t.verbose = true
diff --git a/activesupport/test/abstract_unit.rb b/activesupport/test/abstract_unit.rb
index 01e60abd99..0a778f1af8 100644
--- a/activesupport/test/abstract_unit.rb
+++ b/activesupport/test/abstract_unit.rb
@@ -2,6 +2,7 @@
 
 ORIG_ARGV = ARGV.dup
 
+require "bundler/setup"
 require "active_support/core_ext/kernel/reporting"
 
 silence_warnings do
diff --git a/activesupport/test/actionable_error_test.rb b/activesupport/test/actionable_error_test.rb
index 63046b937c..4f9429b321 100644
--- a/activesupport/test/actionable_error_test.rb
+++ b/activesupport/test/actionable_error_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/actionable_error"
 
 class ActionableErrorTest < ActiveSupport::TestCase
diff --git a/activesupport/test/array_inquirer_test.rb b/activesupport/test/array_inquirer_test.rb
index 9a260edd8a..2c31c50fc6 100644
--- a/activesupport/test/array_inquirer_test.rb
+++ b/activesupport/test/array_inquirer_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/array"
 
 class ArrayInquirerTest < ActiveSupport::TestCase
diff --git a/activesupport/test/autoload_test.rb b/activesupport/test/autoload_test.rb
index 216b069420..52be2b5018 100644
--- a/activesupport/test/autoload_test.rb
+++ b/activesupport/test/autoload_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class TestAutoloadModule < ActiveSupport::TestCase
   include ActiveSupport::Testing::Isolation
@@ -16,6 +16,11 @@ class TestAutoloadModule < ActiveSupport::TestCase
   def setup
     @some_class_path = File.expand_path("test/fixtures/autoload/some_class.rb")
     @another_class_path = File.expand_path("test/fixtures/autoload/another_class.rb")
+    $LOAD_PATH << "test"
+  end
+
+  def teardown
+    $LOAD_PATH.pop
   end
 
   test "the autoload module works like normal autoload" do
diff --git a/activesupport/test/benchmarkable_test.rb b/activesupport/test/benchmarkable_test.rb
index 59a71d99be..a3224c82aa 100644
--- a/activesupport/test/benchmarkable_test.rb
+++ b/activesupport/test/benchmarkable_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class BenchmarkableTest < ActiveSupport::TestCase
   include ActiveSupport::Benchmarkable
diff --git a/activesupport/test/broadcast_logger_test.rb b/activesupport/test/broadcast_logger_test.rb
index 7dfa8a62bd..673b66b56f 100644
--- a/activesupport/test/broadcast_logger_test.rb
+++ b/activesupport/test/broadcast_logger_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 module ActiveSupport
   class BroadcastLoggerTest < TestCase
diff --git a/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb b/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb
index b340eb6c48..25e3550c02 100644
--- a/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb
+++ b/activesupport/test/cache/behaviors/autoloading_cache_behavior.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "dependencies_test_helpers"
+require_relative "../../dependencies_test_helpers"
 
 module AutoloadingCacheBehavior
   include DependenciesTestHelpers
diff --git a/activesupport/test/cache/cache_entry_test.rb b/activesupport/test/cache/cache_entry_test.rb
index ec20a288e1..b7497afd8e 100644
--- a/activesupport/test/cache/cache_entry_test.rb
+++ b/activesupport/test/cache/cache_entry_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/cache"
 
 class CacheEntryTest < ActiveSupport::TestCase
diff --git a/activesupport/test/cache/cache_key_test.rb b/activesupport/test/cache/cache_key_test.rb
index 0ed98dac9c..e66e55d2d7 100644
--- a/activesupport/test/cache/cache_key_test.rb
+++ b/activesupport/test/cache/cache_key_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/cache"
 
 class CacheKeyTest < ActiveSupport::TestCase
diff --git a/activesupport/test/cache/cache_store_logger_test.rb b/activesupport/test/cache/cache_store_logger_test.rb
index 4648b2d361..82a53197b5 100644
--- a/activesupport/test/cache/cache_store_logger_test.rb
+++ b/activesupport/test/cache/cache_store_logger_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/cache"
 
 class CacheStoreLoggerTest < ActiveSupport::TestCase
diff --git a/activesupport/test/cache/cache_store_namespace_test.rb b/activesupport/test/cache/cache_store_namespace_test.rb
index dfdb3262f2..5e8dbd939b 100644
--- a/activesupport/test/cache/cache_store_namespace_test.rb
+++ b/activesupport/test/cache/cache_store_namespace_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/cache"
 
 class CacheStoreNamespaceTest < ActiveSupport::TestCase
diff --git a/activesupport/test/cache/cache_store_setting_test.rb b/activesupport/test/cache/cache_store_setting_test.rb
index 19345ca10f..a258f9b8b8 100644
--- a/activesupport/test/cache/cache_store_setting_test.rb
+++ b/activesupport/test/cache/cache_store_setting_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/cache"
 require "dalli"
 
diff --git a/activesupport/test/cache/local_cache_middleware_test.rb b/activesupport/test/cache/local_cache_middleware_test.rb
index e46fa59784..c39e41832c 100644
--- a/activesupport/test/cache/local_cache_middleware_test.rb
+++ b/activesupport/test/cache/local_cache_middleware_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/cache"
 
 module ActiveSupport
diff --git a/activesupport/test/cache/stores/file_store_test.rb b/activesupport/test/cache/stores/file_store_test.rb
index 2eb06cbe5e..5d6f051928 100644
--- a/activesupport/test/cache/stores/file_store_test.rb
+++ b/activesupport/test/cache/stores/file_store_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/cache"
 require_relative "../behaviors"
 require "pathname"
diff --git a/activesupport/test/cache/stores/mem_cache_store_test.rb b/activesupport/test/cache/stores/mem_cache_store_test.rb
index 0a5e20ed46..56b04124a2 100644
--- a/activesupport/test/cache/stores/mem_cache_store_test.rb
+++ b/activesupport/test/cache/stores/mem_cache_store_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/cache"
 require_relative "../behaviors"
 require "dalli"
diff --git a/activesupport/test/cache/stores/memory_store_test.rb b/activesupport/test/cache/stores/memory_store_test.rb
index bbad9f6622..c833f00aa2 100644
--- a/activesupport/test/cache/stores/memory_store_test.rb
+++ b/activesupport/test/cache/stores/memory_store_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/cache"
 require_relative "../behaviors"
 
diff --git a/activesupport/test/cache/stores/null_store_test.rb b/activesupport/test/cache/stores/null_store_test.rb
index a891cbffc8..925ae00c86 100644
--- a/activesupport/test/cache/stores/null_store_test.rb
+++ b/activesupport/test/cache/stores/null_store_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/cache"
 require_relative "../behaviors"
 
diff --git a/activesupport/test/cache/stores/redis_cache_store_test.rb b/activesupport/test/cache/stores/redis_cache_store_test.rb
index 1cb134dbb7..cb950dd269 100644
--- a/activesupport/test/cache/stores/redis_cache_store_test.rb
+++ b/activesupport/test/cache/stores/redis_cache_store_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/cache"
 require "active_support/cache/redis_cache_store"
 require_relative "../behaviors"
diff --git a/activesupport/test/callback_inheritance_test.rb b/activesupport/test/callback_inheritance_test.rb
index 5633b6e2b8..8af7549762 100644
--- a/activesupport/test/callback_inheritance_test.rb
+++ b/activesupport/test/callback_inheritance_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class GrandParent
   include ActiveSupport::Callbacks
diff --git a/activesupport/test/callbacks_test.rb b/activesupport/test/callbacks_test.rb
index 221a8a5731..6e26147671 100644
--- a/activesupport/test/callbacks_test.rb
+++ b/activesupport/test/callbacks_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 module CallbacksTest
   class Record
diff --git a/activesupport/test/class_cache_test.rb b/activesupport/test/class_cache_test.rb
index 1ef1939b4b..4c517d00b1 100644
--- a/activesupport/test/class_cache_test.rb
+++ b/activesupport/test/class_cache_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/dependencies"
 
 module ActiveSupport
diff --git a/activesupport/test/clean_backtrace_test.rb b/activesupport/test/clean_backtrace_test.rb
index a0a7056952..2145abb483 100644
--- a/activesupport/test/clean_backtrace_test.rb
+++ b/activesupport/test/clean_backtrace_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class BacktraceCleanerFilterTest < ActiveSupport::TestCase
   def setup
diff --git a/activesupport/test/clean_logger_test.rb b/activesupport/test/clean_logger_test.rb
index 6d8f7064ce..4e3e69b74e 100644
--- a/activesupport/test/clean_logger_test.rb
+++ b/activesupport/test/clean_logger_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "stringio"
 require "active_support/logger"
 
diff --git a/activesupport/test/concern_test.rb b/activesupport/test/concern_test.rb
index 4b3cfcd1d2..40f27ef4e9 100644
--- a/activesupport/test/concern_test.rb
+++ b/activesupport/test/concern_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/concern"
 
 class ConcernTest < ActiveSupport::TestCase
diff --git a/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb b/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb
index 2d0f45ec5f..8b15b5a6f9 100644
--- a/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb
+++ b/activesupport/test/concurrency/load_interlock_aware_monitor_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "concurrent/atomic/count_down_latch"
 require "active_support/concurrency/load_interlock_aware_monitor"
 
diff --git a/activesupport/test/configurable_test.rb b/activesupport/test/configurable_test.rb
index 1cf40261dc..a466a1d11d 100644
--- a/activesupport/test/configurable_test.rb
+++ b/activesupport/test/configurable_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/configurable"
 
 class ConfigurableActiveSupport < ActiveSupport::TestCase
diff --git a/activesupport/test/constantize_test_cases.rb b/activesupport/test/constantize_test_cases.rb
index cdb8441b81..fecabc4086 100644
--- a/activesupport/test/constantize_test_cases.rb
+++ b/activesupport/test/constantize_test_cases.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "dependencies_test_helpers"
+require_relative "dependencies_test_helpers"
 
 module Ace
   module Base
diff --git a/activesupport/test/core_ext/array/access_test.rb b/activesupport/test/core_ext/array/access_test.rb
index 427b058925..275f8548e1 100644
--- a/activesupport/test/core_ext/array/access_test.rb
+++ b/activesupport/test/core_ext/array/access_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/array"
 
 class AccessTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/array/conversions_test.rb b/activesupport/test/core_ext/array/conversions_test.rb
index 0a7c43d421..a4869496b2 100644
--- a/activesupport/test/core_ext/array/conversions_test.rb
+++ b/activesupport/test/core_ext/array/conversions_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/array"
 require "active_support/core_ext/big_decimal"
 require "active_support/core_ext/hash"
diff --git a/activesupport/test/core_ext/array/extract_options_test.rb b/activesupport/test/core_ext/array/extract_options_test.rb
index 7a4b15cd71..7c126954b3 100644
--- a/activesupport/test/core_ext/array/extract_options_test.rb
+++ b/activesupport/test/core_ext/array/extract_options_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/array"
 require "active_support/core_ext/hash"
 
diff --git a/activesupport/test/core_ext/array/extract_test.rb b/activesupport/test/core_ext/array/extract_test.rb
index f26e055033..069ab5c8f7 100644
--- a/activesupport/test/core_ext/array/extract_test.rb
+++ b/activesupport/test/core_ext/array/extract_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/array"
 
 class ExtractTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/array/grouping_test.rb b/activesupport/test/core_ext/array/grouping_test.rb
index 37111a5d7d..0e20932f44 100644
--- a/activesupport/test/core_ext/array/grouping_test.rb
+++ b/activesupport/test/core_ext/array/grouping_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/array"
 
 class GroupingTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/array/prepend_append_test.rb b/activesupport/test/core_ext/array/prepend_append_test.rb
index 8573dbd5a6..8fbead8a46 100644
--- a/activesupport/test/core_ext/array/prepend_append_test.rb
+++ b/activesupport/test/core_ext/array/prepend_append_test.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
+require "active_support/core_ext/array"
 
 class PrependAppendTest < ActiveSupport::TestCase
   def test_requiring_prepend_and_append_is_deprecated
diff --git a/activesupport/test/core_ext/array/wrap_test.rb b/activesupport/test/core_ext/array/wrap_test.rb
index 46564b4d73..7c69d9da79 100644
--- a/activesupport/test/core_ext/array/wrap_test.rb
+++ b/activesupport/test/core_ext/array/wrap_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/array"
 
 class WrapTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/bigdecimal_test.rb b/activesupport/test/core_ext/bigdecimal_test.rb
index 62588be33b..356a87f4bc 100644
--- a/activesupport/test/core_ext/bigdecimal_test.rb
+++ b/activesupport/test/core_ext/bigdecimal_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/big_decimal"
 
 class BigDecimalTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/class/attribute_test.rb b/activesupport/test/core_ext/class/attribute_test.rb
index be6ad82367..aafb78ffa9 100644
--- a/activesupport/test/core_ext/class/attribute_test.rb
+++ b/activesupport/test/core_ext/class/attribute_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/class/attribute"
 
 class ClassAttributeTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/class_test.rb b/activesupport/test/core_ext/class_test.rb
index 5ea288738e..5a18accc00 100644
--- a/activesupport/test/core_ext/class_test.rb
+++ b/activesupport/test/core_ext/class_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/class"
 require "set"
 
diff --git a/activesupport/test/core_ext/date_and_time_behavior.rb b/activesupport/test/core_ext/date_and_time_behavior.rb
index 6d31734f27..2dff04d64a 100644
--- a/activesupport/test/core_ext/date_and_time_behavior.rb
+++ b/activesupport/test/core_ext/date_and_time_behavior.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 
 module DateAndTimeBehavior
   def test_yesterday
diff --git a/activesupport/test/core_ext/date_and_time_compatibility_test.rb b/activesupport/test/core_ext/date_and_time_compatibility_test.rb
index 58a24b60b6..6c360c8602 100644
--- a/activesupport/test/core_ext/date_and_time_compatibility_test.rb
+++ b/activesupport/test/core_ext/date_and_time_compatibility_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
-require "time_zone_test_helpers"
+require_relative "../time_zone_test_helpers"
 
 class DateAndTimeCompatibilityTest < ActiveSupport::TestCase
   include TimeZoneTestHelpers
diff --git a/activesupport/test/core_ext/date_ext_test.rb b/activesupport/test/core_ext/date_ext_test.rb
index 7060dd3c56..ea93663329 100644
--- a/activesupport/test/core_ext/date_ext_test.rb
+++ b/activesupport/test/core_ext/date_ext_test.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
-require "core_ext/date_and_time_behavior"
-require "time_zone_test_helpers"
+require_relative "../core_ext/date_and_time_behavior"
+require_relative "../time_zone_test_helpers"
 
 class DateExtCalculationsTest < ActiveSupport::TestCase
   def date_time_init(year, month, day, *args)
diff --git a/activesupport/test/core_ext/date_time_ext_test.rb b/activesupport/test/core_ext/date_time_ext_test.rb
index f9f6b21c9b..0894e1d7dd 100644
--- a/activesupport/test/core_ext/date_time_ext_test.rb
+++ b/activesupport/test/core_ext/date_time_ext_test.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
-require "core_ext/date_and_time_behavior"
-require "time_zone_test_helpers"
+require_relative "../core_ext/date_and_time_behavior"
+require_relative "../time_zone_test_helpers"
 
 class DateTimeExtCalculationsTest < ActiveSupport::TestCase
   def date_time_init(year, month, day, hour, minute, second, usec = 0)
diff --git a/activesupport/test/core_ext/digest/uuid_test.rb b/activesupport/test/core_ext/digest/uuid_test.rb
index 94cb7d9418..1934591476 100644
--- a/activesupport/test/core_ext/digest/uuid_test.rb
+++ b/activesupport/test/core_ext/digest/uuid_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/digest/uuid"
 
 class DigestUUIDExt < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/duration_test.rb b/activesupport/test/core_ext/duration_test.rb
index 84c01a5fe7..3ad883cb8a 100644
--- a/activesupport/test/core_ext/duration_test.rb
+++ b/activesupport/test/core_ext/duration_test.rb
@@ -1,10 +1,10 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/inflector"
 require "active_support/time"
 require "active_support/json"
-require "time_zone_test_helpers"
+require_relative "../time_zone_test_helpers"
 require "yaml"
 
 class DurationTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/enumerable_test.rb b/activesupport/test/core_ext/enumerable_test.rb
index a9bf4b82f4..a90545c817 100644
--- a/activesupport/test/core_ext/enumerable_test.rb
+++ b/activesupport/test/core_ext/enumerable_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/array"
 require "active_support/core_ext/enumerable"
 
diff --git a/activesupport/test/core_ext/file_test.rb b/activesupport/test/core_ext/file_test.rb
index 186c863f91..0c32858809 100644
--- a/activesupport/test/core_ext/file_test.rb
+++ b/activesupport/test/core_ext/file_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/file"
 
 class AtomicWriteTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/hash/transform_values_test.rb b/activesupport/test/core_ext/hash/transform_values_test.rb
index e481b5e4a9..37c51dabf7 100644
--- a/activesupport/test/core_ext/hash/transform_values_test.rb
+++ b/activesupport/test/core_ext/hash/transform_values_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/hash/indifferent_access"
 
 class TransformValuesDeprecatedRequireTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/hash_ext_test.rb b/activesupport/test/core_ext/hash_ext_test.rb
index 59d2d6f530..fb45769c19 100644
--- a/activesupport/test/core_ext/hash_ext_test.rb
+++ b/activesupport/test/core_ext/hash_ext_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/hash"
 require "bigdecimal"
 require "active_support/core_ext/string/access"
diff --git a/activesupport/test/core_ext/integer_ext_test.rb b/activesupport/test/core_ext/integer_ext_test.rb
index 5691dc5341..bb82c10936 100644
--- a/activesupport/test/core_ext/integer_ext_test.rb
+++ b/activesupport/test/core_ext/integer_ext_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/integer"
 
 class IntegerExtTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/kernel/concern_test.rb b/activesupport/test/core_ext/kernel/concern_test.rb
index b40ff6a623..9730a74b4a 100644
--- a/activesupport/test/core_ext/kernel/concern_test.rb
+++ b/activesupport/test/core_ext/kernel/concern_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/kernel/concern"
 
 class KernelConcernTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/kernel_test.rb b/activesupport/test/core_ext/kernel_test.rb
index ef11e10af8..505192ba1b 100644
--- a/activesupport/test/core_ext/kernel_test.rb
+++ b/activesupport/test/core_ext/kernel_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/kernel"
 
 class KernelTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/load_error_test.rb b/activesupport/test/core_ext/load_error_test.rb
index 6d3726e407..ad3e0749fc 100644
--- a/activesupport/test/core_ext/load_error_test.rb
+++ b/activesupport/test/core_ext/load_error_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/load_error"
 
 class TestLoadError < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/marshal_test.rb b/activesupport/test/core_ext/marshal_test.rb
index 7ac051b4b1..5e72518651 100644
--- a/activesupport/test/core_ext/marshal_test.rb
+++ b/activesupport/test/core_ext/marshal_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/marshal"
-require "dependencies_test_helpers"
+require_relative "../dependencies_test_helpers"
 
 class MarshalTest < ActiveSupport::TestCase
   include ActiveSupport::Testing::Isolation
diff --git a/activesupport/test/core_ext/module/anonymous_test.rb b/activesupport/test/core_ext/module/anonymous_test.rb
index e03c217015..0fda237189 100644
--- a/activesupport/test/core_ext/module/anonymous_test.rb
+++ b/activesupport/test/core_ext/module/anonymous_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/anonymous"
 
 class AnonymousTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/module/attr_internal_test.rb b/activesupport/test/core_ext/module/attr_internal_test.rb
index 9a65f75497..1893eed2b4 100644
--- a/activesupport/test/core_ext/module/attr_internal_test.rb
+++ b/activesupport/test/core_ext/module/attr_internal_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/attr_internal"
 
 class AttrInternalTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/module/attribute_accessor_per_thread_test.rb b/activesupport/test/core_ext/module/attribute_accessor_per_thread_test.rb
index a2b3239884..c636b8c03e 100644
--- a/activesupport/test/core_ext/module/attribute_accessor_per_thread_test.rb
+++ b/activesupport/test/core_ext/module/attribute_accessor_per_thread_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/attribute_accessors_per_thread"
 
 class ModuleAttributeAccessorPerThreadTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/module/attribute_accessor_test.rb b/activesupport/test/core_ext/module/attribute_accessor_test.rb
index 33c583947a..7ac76251df 100644
--- a/activesupport/test/core_ext/module/attribute_accessor_test.rb
+++ b/activesupport/test/core_ext/module/attribute_accessor_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/attribute_accessors"
 
 class ModuleAttributeAccessorTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/module/attribute_aliasing_test.rb b/activesupport/test/core_ext/module/attribute_aliasing_test.rb
index 81aac224f9..665866ac6f 100644
--- a/activesupport/test/core_ext/module/attribute_aliasing_test.rb
+++ b/activesupport/test/core_ext/module/attribute_aliasing_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/aliasing"
 
 module AttributeAliasing
diff --git a/activesupport/test/core_ext/module/concerning_test.rb b/activesupport/test/core_ext/module/concerning_test.rb
index 38fd60463d..8aad4b5805 100644
--- a/activesupport/test/core_ext/module/concerning_test.rb
+++ b/activesupport/test/core_ext/module/concerning_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/concerning"
 
 class ModuleConcerningTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/module/introspection_test.rb b/activesupport/test/core_ext/module/introspection_test.rb
index d8409d5e44..f9f649ce81 100644
--- a/activesupport/test/core_ext/module/introspection_test.rb
+++ b/activesupport/test/core_ext/module/introspection_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/introspection"
 
 module ParentA
diff --git a/activesupport/test/core_ext/module/remove_method_test.rb b/activesupport/test/core_ext/module/remove_method_test.rb
index a18fc0a5e4..e24cab5fdd 100644
--- a/activesupport/test/core_ext/module/remove_method_test.rb
+++ b/activesupport/test/core_ext/module/remove_method_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/module/remove_method"
 
 module RemoveMethodTests
diff --git a/activesupport/test/core_ext/module_test.rb b/activesupport/test/core_ext/module_test.rb
index dd36a9373a..2cdbca08c7 100644
--- a/activesupport/test/core_ext/module_test.rb
+++ b/activesupport/test/core_ext/module_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/module"
 
 Somewhere = Struct.new(:street, :city) do
diff --git a/activesupport/test/core_ext/name_error_test.rb b/activesupport/test/core_ext/name_error_test.rb
index 5c6c12ffc7..1ca411ca8a 100644
--- a/activesupport/test/core_ext/name_error_test.rb
+++ b/activesupport/test/core_ext/name_error_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/name_error"
 
 class NameErrorTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/numeric_ext_test.rb b/activesupport/test/core_ext/numeric_ext_test.rb
index 5005b9febd..b9c1748e99 100644
--- a/activesupport/test/core_ext/numeric_ext_test.rb
+++ b/activesupport/test/core_ext/numeric_ext_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
 require "active_support/core_ext/numeric"
 require "active_support/core_ext/integer"
diff --git a/activesupport/test/core_ext/object/acts_like_test.rb b/activesupport/test/core_ext/object/acts_like_test.rb
index 8aa9eb036a..6584bedd34 100644
--- a/activesupport/test/core_ext/object/acts_like_test.rb
+++ b/activesupport/test/core_ext/object/acts_like_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/date/acts_like"
 require "active_support/core_ext/time/acts_like"
 require "active_support/core_ext/date_time/acts_like"
diff --git a/activesupport/test/core_ext/object/blank_test.rb b/activesupport/test/core_ext/object/blank_test.rb
index 954f415383..e91d827704 100644
--- a/activesupport/test/core_ext/object/blank_test.rb
+++ b/activesupport/test/core_ext/object/blank_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/object/blank"
 
 class BlankTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/object/deep_dup_test.rb b/activesupport/test/core_ext/object/deep_dup_test.rb
index 8e5e28c513..1fef3129c6 100644
--- a/activesupport/test/core_ext/object/deep_dup_test.rb
+++ b/activesupport/test/core_ext/object/deep_dup_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/object/deep_dup"
 
 class DeepDupTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/object/duplicable_test.rb b/activesupport/test/core_ext/object/duplicable_test.rb
index a577c30c40..69932dffa1 100644
--- a/activesupport/test/core_ext/object/duplicable_test.rb
+++ b/activesupport/test/core_ext/object/duplicable_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "bigdecimal"
 require "active_support/core_ext/object/duplicable"
 require "active_support/core_ext/numeric/time"
diff --git a/activesupport/test/core_ext/object/inclusion_test.rb b/activesupport/test/core_ext/object/inclusion_test.rb
index 8cbb4f848f..df73af9934 100644
--- a/activesupport/test/core_ext/object/inclusion_test.rb
+++ b/activesupport/test/core_ext/object/inclusion_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/object/inclusion"
 
 class InTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/object/instance_variables_test.rb b/activesupport/test/core_ext/object/instance_variables_test.rb
index dd710e9349..9c7b97c64b 100644
--- a/activesupport/test/core_ext/object/instance_variables_test.rb
+++ b/activesupport/test/core_ext/object/instance_variables_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/object/instance_variables"
 
 class ObjectInstanceVariableTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/object/json_cherry_pick_test.rb b/activesupport/test/core_ext/object/json_cherry_pick_test.rb
index 22659a4050..b11b25248e 100644
--- a/activesupport/test/core_ext/object/json_cherry_pick_test.rb
+++ b/activesupport/test/core_ext/object/json_cherry_pick_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 
 # These test cases were added to test that cherry-picking the json extensions
 # works correctly, primarily for dependencies problems reported in #16131. They
diff --git a/activesupport/test/core_ext/object/json_gem_encoding_test.rb b/activesupport/test/core_ext/object/json_gem_encoding_test.rb
index eef02f7458..c80fac2ab1 100644
--- a/activesupport/test/core_ext/object/json_gem_encoding_test.rb
+++ b/activesupport/test/core_ext/object/json_gem_encoding_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "json"
-require "json/encoding_test_cases"
+require_relative "../../json/encoding_test_cases"
 
 # These test cases were added to test that we do not interfere with json gem's
 # output when the AS encoder is loaded, primarily for problems reported in
diff --git a/activesupport/test/core_ext/object/to_param_test.rb b/activesupport/test/core_ext/object/to_param_test.rb
index 612156bd99..2493c25b2a 100644
--- a/activesupport/test/core_ext/object/to_param_test.rb
+++ b/activesupport/test/core_ext/object/to_param_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/core_ext/object/to_param"
 
 class ToParamTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/object/to_query_test.rb b/activesupport/test/core_ext/object/to_query_test.rb
index 561dadbbcf..3f70767997 100644
--- a/activesupport/test/core_ext/object/to_query_test.rb
+++ b/activesupport/test/core_ext/object/to_query_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../../abstract_unit"
 require "active_support/ordered_hash"
 require "active_support/core_ext/object/to_query"
 require "active_support/core_ext/string/output_safety"
diff --git a/activesupport/test/core_ext/object/try_test.rb b/activesupport/test/core_ext/object/try_test.rb
index d501b5edce..135acdd4be 100644
--- a/activesupport/test/core_ext/object/try_test.rb
+++ b/activesupport/test/core_ext/object/try_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "active_support/core_ext/object/try"
+require_relative "../../abstract_unit"
+require "active_support/core_ext/object"
 
 class ObjectTryTest < ActiveSupport::TestCase
   def setup
diff --git a/activesupport/test/core_ext/range_ext_test.rb b/activesupport/test/core_ext/range_ext_test.rb
index 428644339e..f29bfdcf14 100644
--- a/activesupport/test/core_ext/range_ext_test.rb
+++ b/activesupport/test/core_ext/range_ext_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
 require "active_support/core_ext/numeric"
 require "active_support/core_ext/range"
diff --git a/activesupport/test/core_ext/regexp_ext_test.rb b/activesupport/test/core_ext/regexp_ext_test.rb
index 7d18297b64..5b074c46eb 100644
--- a/activesupport/test/core_ext/regexp_ext_test.rb
+++ b/activesupport/test/core_ext/regexp_ext_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/regexp"
 
 class RegexpExtAccessTests < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/secure_random_test.rb b/activesupport/test/core_ext/secure_random_test.rb
index 4b73233971..5003eff1d4 100644
--- a/activesupport/test/core_ext/secure_random_test.rb
+++ b/activesupport/test/core_ext/secure_random_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/securerandom"
 
 class SecureRandomTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/string_ext_test.rb b/activesupport/test/core_ext/string_ext_test.rb
index af8f9c9b09..f27a4423d3 100644
--- a/activesupport/test/core_ext/string_ext_test.rb
+++ b/activesupport/test/core_ext/string_ext_test.rb
@@ -1,10 +1,10 @@
 # frozen_string_literal: true
 
 require "date"
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "timeout"
-require "inflector_test_cases"
-require "constantize_test_cases"
+require_relative "../inflector_test_cases"
+require_relative "../constantize_test_cases"
 
 require "active_support/inflector"
 require "active_support/core_ext/string"
@@ -12,7 +12,7 @@ require "active_support/time"
 require "active_support/core_ext/string/output_safety"
 require "active_support/core_ext/string/indent"
 require "active_support/core_ext/string/strip"
-require "time_zone_test_helpers"
+require_relative "../time_zone_test_helpers"
 require "yaml"
 
 class StringInflectionsTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/time_ext_test.rb b/activesupport/test/core_ext/time_ext_test.rb
index f8c921104c..f8bfbb5779 100644
--- a/activesupport/test/core_ext/time_ext_test.rb
+++ b/activesupport/test/core_ext/time_ext_test.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
-require "core_ext/date_and_time_behavior"
-require "time_zone_test_helpers"
+require_relative "../core_ext/date_and_time_behavior"
+require_relative "../time_zone_test_helpers"
 
 class TimeExtCalculationsTest < ActiveSupport::TestCase
   def date_time_init(year, month, day, hour, minute, second, usec = 0)
diff --git a/activesupport/test/core_ext/time_with_zone_test.rb b/activesupport/test/core_ext/time_with_zone_test.rb
index f6e836e446..3bcc74acb7 100644
--- a/activesupport/test/core_ext/time_with_zone_test.rb
+++ b/activesupport/test/core_ext/time_with_zone_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/time"
-require "time_zone_test_helpers"
+require_relative "../time_zone_test_helpers"
 require "yaml"
 
 class TimeWithZoneTest < ActiveSupport::TestCase
diff --git a/activesupport/test/core_ext/uri_ext_test.rb b/activesupport/test/core_ext/uri_ext_test.rb
index c0686bc720..f8f17d3874 100644
--- a/activesupport/test/core_ext/uri_ext_test.rb
+++ b/activesupport/test/core_ext/uri_ext_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "uri"
 require "active_support/core_ext/uri"
 
diff --git a/activesupport/test/current_attributes_test.rb b/activesupport/test/current_attributes_test.rb
index 4cbf462da0..33eb22d3a1 100644
--- a/activesupport/test/current_attributes_test.rb
+++ b/activesupport/test/current_attributes_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class CurrentAttributesTest < ActiveSupport::TestCase
   Person = Struct.new(:id, :name, :time_zone)
diff --git a/activesupport/test/dependencies_test.rb b/activesupport/test/dependencies_test.rb
index 1d06141108..bfe093427b 100644
--- a/activesupport/test/dependencies_test.rb
+++ b/activesupport/test/dependencies_test.rb
@@ -1,8 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
+require "pp"
 require "active_support/dependencies"
-require "dependencies_test_helpers"
+require_relative "dependencies_test_helpers"
 
 module ModuleWithMissing
   mattr_accessor :missing_count
@@ -21,11 +22,13 @@ class DependenciesTest < ActiveSupport::TestCase
 
   setup do
     @loaded_features_copy = $LOADED_FEATURES.dup
+    $LOAD_PATH << "test"
   end
 
   teardown do
     ActiveSupport::Dependencies.clear
     $LOADED_FEATURES.replace(@loaded_features_copy)
+    $LOAD_PATH.pop
   end
 
   def test_depend_on_path
diff --git a/activesupport/test/deprecation/method_wrappers_test.rb b/activesupport/test/deprecation/method_wrappers_test.rb
index 8c40534452..dc47178e70 100644
--- a/activesupport/test/deprecation/method_wrappers_test.rb
+++ b/activesupport/test/deprecation/method_wrappers_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/deprecation"
 
 class MethodWrappersTest < ActiveSupport::TestCase
diff --git a/activesupport/test/deprecation/proxy_wrappers_test.rb b/activesupport/test/deprecation/proxy_wrappers_test.rb
index 9e26052fb4..631d75d708 100644
--- a/activesupport/test/deprecation/proxy_wrappers_test.rb
+++ b/activesupport/test/deprecation/proxy_wrappers_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/deprecation"
 
 class ProxyWrappersTest < ActiveSupport::TestCase
diff --git a/activesupport/test/deprecation_test.rb b/activesupport/test/deprecation_test.rb
index 3c38083add..534e3d82d8 100644
--- a/activesupport/test/deprecation_test.rb
+++ b/activesupport/test/deprecation_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/testing/stream"
 
 class Deprecatee
diff --git a/activesupport/test/descendants_tracker_with_autoloading_test.rb b/activesupport/test/descendants_tracker_with_autoloading_test.rb
index d4fedb5a67..71dc0f292f 100644
--- a/activesupport/test/descendants_tracker_with_autoloading_test.rb
+++ b/activesupport/test/descendants_tracker_with_autoloading_test.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/descendants_tracker"
 require "active_support/dependencies"
-require "descendants_tracker_test_cases"
+require_relative "descendants_tracker_test_cases"
 
 class DescendantsTrackerWithAutoloadingTest < ActiveSupport::TestCase
   include DescendantsTrackerTestCases
diff --git a/activesupport/test/descendants_tracker_without_autoloading_test.rb b/activesupport/test/descendants_tracker_without_autoloading_test.rb
index c65f69cba3..a49c552bed 100644
--- a/activesupport/test/descendants_tracker_without_autoloading_test.rb
+++ b/activesupport/test/descendants_tracker_without_autoloading_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/descendants_tracker"
-require "descendants_tracker_test_cases"
+require_relative "descendants_tracker_test_cases"
 
 class DescendantsTrackerWithoutAutoloadingTest < ActiveSupport::TestCase
   include DescendantsTrackerTestCases
diff --git a/activesupport/test/digest_test.rb b/activesupport/test/digest_test.rb
index 83ff2a8d83..0ad8350b6e 100644
--- a/activesupport/test/digest_test.rb
+++ b/activesupport/test/digest_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "openssl"
 
 class DigestTest < ActiveSupport::TestCase
diff --git a/activesupport/test/encrypted_configuration_test.rb b/activesupport/test/encrypted_configuration_test.rb
index 387d6e1c1f..17fc3ef88f 100644
--- a/activesupport/test/encrypted_configuration_test.rb
+++ b/activesupport/test/encrypted_configuration_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/encrypted_configuration"
 
 class EncryptedConfigurationTest < ActiveSupport::TestCase
diff --git a/activesupport/test/encrypted_file_test.rb b/activesupport/test/encrypted_file_test.rb
index 0954448cdd..53ae1c3855 100644
--- a/activesupport/test/encrypted_file_test.rb
+++ b/activesupport/test/encrypted_file_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/encrypted_file"
 
 class EncryptedFileTest < ActiveSupport::TestCase
diff --git a/activesupport/test/evented_file_update_checker_test.rb b/activesupport/test/evented_file_update_checker_test.rb
index bcde95d5ab..f67f4fb105 100644
--- a/activesupport/test/evented_file_update_checker_test.rb
+++ b/activesupport/test/evented_file_update_checker_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "pathname"
-require "file_update_checker_shared_tests"
+require_relative "file_update_checker_shared_tests"
 
 class EventedFileUpdateCheckerTest < ActiveSupport::TestCase
   include FileUpdateCheckerSharedTests
diff --git a/activesupport/test/executor_test.rb b/activesupport/test/executor_test.rb
index 3026f002c3..ac87780b23 100644
--- a/activesupport/test/executor_test.rb
+++ b/activesupport/test/executor_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class ExecutorTest < ActiveSupport::TestCase
   class DummyError < RuntimeError
diff --git a/activesupport/test/file_update_checker_test.rb b/activesupport/test/file_update_checker_test.rb
index ec1df0df67..b067595410 100644
--- a/activesupport/test/file_update_checker_test.rb
+++ b/activesupport/test/file_update_checker_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "file_update_checker_shared_tests"
+require_relative "abstract_unit"
+require_relative "file_update_checker_shared_tests"
 
 class FileUpdateCheckerTest < ActiveSupport::TestCase
   include FileUpdateCheckerSharedTests
diff --git a/activesupport/test/fork_tracker_test.rb b/activesupport/test/fork_tracker_test.rb
index b434082f0c..4c7274bdb9 100644
--- a/activesupport/test/fork_tracker_test.rb
+++ b/activesupport/test/fork_tracker_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class ForkTrackerTest < ActiveSupport::TestCase
   def test_object_fork
diff --git a/activesupport/test/gzip_test.rb b/activesupport/test/gzip_test.rb
index 3d790f69c4..c0dc93f3b6 100644
--- a/activesupport/test/gzip_test.rb
+++ b/activesupport/test/gzip_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/object/blank"
 
 class GzipTest < ActiveSupport::TestCase
diff --git a/activesupport/test/hash_with_indifferent_access_test.rb b/activesupport/test/hash_with_indifferent_access_test.rb
index 921a5c115d..c08fd7a590 100644
--- a/activesupport/test/hash_with_indifferent_access_test.rb
+++ b/activesupport/test/hash_with_indifferent_access_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/hash"
 require "bigdecimal"
 require "active_support/core_ext/string/access"
diff --git a/activesupport/test/i18n_test.rb b/activesupport/test/i18n_test.rb
index 8ad9441f9d..6babd7a28c 100644
--- a/activesupport/test/i18n_test.rb
+++ b/activesupport/test/i18n_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/time"
 require "active_support/core_ext/array/conversions"
 
diff --git a/activesupport/test/inflector_test.rb b/activesupport/test/inflector_test.rb
index ddf765a220..918696cd93 100644
--- a/activesupport/test/inflector_test.rb
+++ b/activesupport/test/inflector_test.rb
@@ -1,10 +1,10 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/inflector"
 
-require "inflector_test_cases"
-require "constantize_test_cases"
+require_relative "inflector_test_cases"
+require_relative "constantize_test_cases"
 
 class InflectorTest < ActiveSupport::TestCase
   include InflectorTestCases
diff --git a/activesupport/test/json/decoding_test.rb b/activesupport/test/json/decoding_test.rb
index 2e8ea01aca..7658b942aa 100644
--- a/activesupport/test/json/decoding_test.rb
+++ b/activesupport/test/json/decoding_test.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/json"
 require "active_support/time"
-require "time_zone_test_helpers"
+require_relative "../time_zone_test_helpers"
 
 class TestJSONDecoding < ActiveSupport::TestCase
   include TimeZoneTestHelpers
diff --git a/activesupport/test/json/encoding_test.rb b/activesupport/test/json/encoding_test.rb
index c4e0b71f26..30a3b8e5a0 100644
--- a/activesupport/test/json/encoding_test.rb
+++ b/activesupport/test/json/encoding_test.rb
@@ -1,12 +1,12 @@
 # frozen_string_literal: true
 
 require "securerandom"
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/core_ext/string/inflections"
 require "active_support/json"
 require "active_support/time"
-require "time_zone_test_helpers"
-require "json/encoding_test_cases"
+require_relative "../time_zone_test_helpers"
+require_relative "../json/encoding_test_cases"
 
 class TestJSONEncoding < ActiveSupport::TestCase
   include TimeZoneTestHelpers
diff --git a/activesupport/test/key_generator_test.rb b/activesupport/test/key_generator_test.rb
index 9dfc0b2154..887707167b 100644
--- a/activesupport/test/key_generator_test.rb
+++ b/activesupport/test/key_generator_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 begin
   require "openssl"
diff --git a/activesupport/test/lazy_load_hooks_test.rb b/activesupport/test/lazy_load_hooks_test.rb
index 5e9a21f047..1356671808 100644
--- a/activesupport/test/lazy_load_hooks_test.rb
+++ b/activesupport/test/lazy_load_hooks_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/module/remove_method"
 
 class LazyLoadHooksTest < ActiveSupport::TestCase
diff --git a/activesupport/test/log_subscriber_test.rb b/activesupport/test/log_subscriber_test.rb
index 7f05459493..d4bd082def 100644
--- a/activesupport/test/log_subscriber_test.rb
+++ b/activesupport/test/log_subscriber_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/log_subscriber/test_helper"
 
 class MyLogSubscriber < ActiveSupport::LogSubscriber
diff --git a/activesupport/test/logger_test.rb b/activesupport/test/logger_test.rb
index 2580434f91..b7f1acf9f5 100644
--- a/activesupport/test/logger_test.rb
+++ b/activesupport/test/logger_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "multibyte_test_helpers"
+require_relative "abstract_unit"
+require_relative "multibyte_test_helpers"
 require "stringio"
 require "fileutils"
 require "tempfile"
diff --git a/activesupport/test/message_encryptor_test.rb b/activesupport/test/message_encryptor_test.rb
index 150c10f750..3c2007c8d6 100644
--- a/activesupport/test/message_encryptor_test.rb
+++ b/activesupport/test/message_encryptor_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "openssl"
 require "active_support/time"
 require "active_support/json"
diff --git a/activesupport/test/message_verifier_test.rb b/activesupport/test/message_verifier_test.rb
index 67781b268d..56c433f8df 100644
--- a/activesupport/test/message_verifier_test.rb
+++ b/activesupport/test/message_verifier_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "openssl"
 require "active_support/time"
 require "active_support/json"
diff --git a/activesupport/test/messages/rotation_configuration_test.rb b/activesupport/test/messages/rotation_configuration_test.rb
index 2f6824ed21..3fb105be58 100644
--- a/activesupport/test/messages/rotation_configuration_test.rb
+++ b/activesupport/test/messages/rotation_configuration_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/messages/rotation_configuration"
 
 class MessagesRotationConfiguration < ActiveSupport::TestCase
diff --git a/activesupport/test/multibyte_chars_test.rb b/activesupport/test/multibyte_chars_test.rb
index b0027047df..ee6f74d1b6 100644
--- a/activesupport/test/multibyte_chars_test.rb
+++ b/activesupport/test/multibyte_chars_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "multibyte_test_helpers"
+require_relative "abstract_unit"
+require_relative "multibyte_test_helpers"
 require "active_support/core_ext/string/multibyte"
 
 class MultibyteCharsTest < ActiveSupport::TestCase
diff --git a/activesupport/test/multibyte_conformance_test.rb b/activesupport/test/multibyte_conformance_test.rb
index b19689723f..95dab84194 100644
--- a/activesupport/test/multibyte_conformance_test.rb
+++ b/activesupport/test/multibyte_conformance_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "multibyte_test_helpers"
+require_relative "abstract_unit"
+require_relative "multibyte_test_helpers"
 
 class MultibyteConformanceTest < ActiveSupport::TestCase
   include MultibyteTestHelpers
diff --git a/activesupport/test/multibyte_grapheme_break_conformance_test.rb b/activesupport/test/multibyte_grapheme_break_conformance_test.rb
index 97963279af..30b1d7c42c 100644
--- a/activesupport/test/multibyte_grapheme_break_conformance_test.rb
+++ b/activesupport/test/multibyte_grapheme_break_conformance_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "multibyte_test_helpers"
+require_relative "abstract_unit"
+require_relative "multibyte_test_helpers"
 
 class MultibyteGraphemeBreakConformanceTest < ActiveSupport::TestCase
   include MultibyteTestHelpers
diff --git a/activesupport/test/multibyte_normalization_conformance_test.rb b/activesupport/test/multibyte_normalization_conformance_test.rb
index 82edf69294..581a1a32d1 100644
--- a/activesupport/test/multibyte_normalization_conformance_test.rb
+++ b/activesupport/test/multibyte_normalization_conformance_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "multibyte_test_helpers"
+require_relative "abstract_unit"
+require_relative "multibyte_test_helpers"
 
 class MultibyteNormalizationConformanceTest < ActiveSupport::TestCase
   include MultibyteTestHelpers
diff --git a/activesupport/test/multibyte_proxy_test.rb b/activesupport/test/multibyte_proxy_test.rb
index ecedab2569..668da7ccfd 100644
--- a/activesupport/test/multibyte_proxy_test.rb
+++ b/activesupport/test/multibyte_proxy_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class MultibyteProxyText < ActiveSupport::TestCase
   class AsciiOnlyEncoder
diff --git a/activesupport/test/notifications/evented_notification_test.rb b/activesupport/test/notifications/evented_notification_test.rb
index ab2a9b8659..3f523044e4 100644
--- a/activesupport/test/notifications/evented_notification_test.rb
+++ b/activesupport/test/notifications/evented_notification_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 
 module ActiveSupport
   module Notifications
diff --git a/activesupport/test/notifications/instrumenter_test.rb b/activesupport/test/notifications/instrumenter_test.rb
index 9729ad5c89..1d10dc7f2d 100644
--- a/activesupport/test/notifications/instrumenter_test.rb
+++ b/activesupport/test/notifications/instrumenter_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/notifications/instrumenter"
 
 module ActiveSupport
diff --git a/activesupport/test/notifications_test.rb b/activesupport/test/notifications_test.rb
index 08277e5436..421b8f8087 100644
--- a/activesupport/test/notifications_test.rb
+++ b/activesupport/test/notifications_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/module/delegation"
 
 module Notifications
diff --git a/activesupport/test/number_helper_i18n_test.rb b/activesupport/test/number_helper_i18n_test.rb
index 365fa96f4d..bfc5d05ea2 100644
--- a/activesupport/test/number_helper_i18n_test.rb
+++ b/activesupport/test/number_helper_i18n_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/number_helper"
 require "active_support/core_ext/hash/keys"
 
diff --git a/activesupport/test/number_helper_test.rb b/activesupport/test/number_helper_test.rb
index 12f3bfef65..d39f155654 100644
--- a/activesupport/test/number_helper_test.rb
+++ b/activesupport/test/number_helper_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/number_helper"
 require "active_support/core_ext/string/output_safety"
 
diff --git a/activesupport/test/option_merger_test.rb b/activesupport/test/option_merger_test.rb
index 1a1cb711dc..668de7c81b 100644
--- a/activesupport/test/option_merger_test.rb
+++ b/activesupport/test/option_merger_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/object/with_options"
 
 class OptionMergerTest < ActiveSupport::TestCase
diff --git a/activesupport/test/ordered_hash_test.rb b/activesupport/test/ordered_hash_test.rb
index c70d3b4c37..8d0d0cfabb 100644
--- a/activesupport/test/ordered_hash_test.rb
+++ b/activesupport/test/ordered_hash_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/json"
 require "active_support/core_ext/object/json"
 require "active_support/core_ext/hash/indifferent_access"
diff --git a/activesupport/test/ordered_options_test.rb b/activesupport/test/ordered_options_test.rb
index 90394fee0a..541b8cddf5 100644
--- a/activesupport/test/ordered_options_test.rb
+++ b/activesupport/test/ordered_options_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/ordered_options"
 
 class OrderedOptionsTest < ActiveSupport::TestCase
diff --git a/activesupport/test/parameter_filter_test.rb b/activesupport/test/parameter_filter_test.rb
index 510921cf95..0bb16f4d27 100644
--- a/activesupport/test/parameter_filter_test.rb
+++ b/activesupport/test/parameter_filter_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/hash"
 require "active_support/parameter_filter"
 
diff --git a/activesupport/test/reloader_test.rb b/activesupport/test/reloader_test.rb
index 1b7cc253d9..6aaebe0b5a 100644
--- a/activesupport/test/reloader_test.rb
+++ b/activesupport/test/reloader_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class ReloaderTest < ActiveSupport::TestCase
   def test_prepare_callback
diff --git a/activesupport/test/rescuable_test.rb b/activesupport/test/rescuable_test.rb
index b1b8a25c5b..f590c58092 100644
--- a/activesupport/test/rescuable_test.rb
+++ b/activesupport/test/rescuable_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class WraithAttack < StandardError
 end
diff --git a/activesupport/test/safe_buffer_test.rb b/activesupport/test/safe_buffer_test.rb
index 9a0ac88a92..abe91fcb24 100644
--- a/activesupport/test/safe_buffer_test.rb
+++ b/activesupport/test/safe_buffer_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/string/inflections"
 require "yaml"
 
diff --git a/activesupport/test/secure_compare_rotator_test.rb b/activesupport/test/secure_compare_rotator_test.rb
index d80faea128..2b7c792625 100644
--- a/activesupport/test/secure_compare_rotator_test.rb
+++ b/activesupport/test/secure_compare_rotator_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/secure_compare_rotator"
 
 class SecureCompareRotatorTest < ActiveSupport::TestCase
diff --git a/activesupport/test/security_utils_test.rb b/activesupport/test/security_utils_test.rb
index fff9cc2a8d..0fe8cdd164 100644
--- a/activesupport/test/security_utils_test.rb
+++ b/activesupport/test/security_utils_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/security_utils"
 
 class SecurityUtilsTest < ActiveSupport::TestCase
diff --git a/activesupport/test/share_lock_test.rb b/activesupport/test/share_lock_test.rb
index 68e78ccc16..915917a7b3 100644
--- a/activesupport/test/share_lock_test.rb
+++ b/activesupport/test/share_lock_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "concurrent/atomic/count_down_latch"
 require "active_support/concurrency/share_lock"
 
diff --git a/activesupport/test/silence_logger_test.rb b/activesupport/test/silence_logger_test.rb
index bd0c6b7f86..ba6c4499d4 100644
--- a/activesupport/test/silence_logger_test.rb
+++ b/activesupport/test/silence_logger_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/logger_silence"
 require "logger"
 
diff --git a/activesupport/test/string_inquirer_test.rb b/activesupport/test/string_inquirer_test.rb
index 09726b144a..4e904e996d 100644
--- a/activesupport/test/string_inquirer_test.rb
+++ b/activesupport/test/string_inquirer_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class StringInquirerTest < ActiveSupport::TestCase
   def setup
diff --git a/activesupport/test/subscriber_test.rb b/activesupport/test/subscriber_test.rb
index 829fba6057..ab6f069e98 100644
--- a/activesupport/test/subscriber_test.rb
+++ b/activesupport/test/subscriber_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/subscriber"
 
 class TestSubscriber < ActiveSupport::Subscriber
diff --git a/activesupport/test/tagged_logging_test.rb b/activesupport/test/tagged_logging_test.rb
index cff73472c3..c63dd20d66 100644
--- a/activesupport/test/tagged_logging_test.rb
+++ b/activesupport/test/tagged_logging_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/logger"
 require "active_support/tagged_logging"
 
diff --git a/activesupport/test/test_case_test.rb b/activesupport/test/test_case_test.rb
index dd75548e9c..00af419737 100644
--- a/activesupport/test/test_case_test.rb
+++ b/activesupport/test/test_case_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 
 class AssertionsTest < ActiveSupport::TestCase
   def setup
diff --git a/activesupport/test/testing/after_teardown_test.rb b/activesupport/test/testing/after_teardown_test.rb
index 961af49479..d90e012016 100644
--- a/activesupport/test/testing/after_teardown_test.rb
+++ b/activesupport/test/testing/after_teardown_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 
 module OtherAfterTeardown
   def after_teardown
diff --git a/activesupport/test/testing/constant_lookup_test.rb b/activesupport/test/testing/constant_lookup_test.rb
index 37b7822950..9712fe21e1 100644
--- a/activesupport/test/testing/constant_lookup_test.rb
+++ b/activesupport/test/testing/constant_lookup_test.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
-require "dependencies_test_helpers"
+require_relative "../abstract_unit"
+require_relative "../dependencies_test_helpers"
 
 class Foo; end
 class Bar < Foo
diff --git a/activesupport/test/testing/file_fixtures_test.rb b/activesupport/test/testing/file_fixtures_test.rb
index 35be8f5206..9ece9def4d 100644
--- a/activesupport/test/testing/file_fixtures_test.rb
+++ b/activesupport/test/testing/file_fixtures_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 
 require "pathname"
 
diff --git a/activesupport/test/testing/method_call_assertions_test.rb b/activesupport/test/testing/method_call_assertions_test.rb
index 669463bd31..ba1d55021a 100644
--- a/activesupport/test/testing/method_call_assertions_test.rb
+++ b/activesupport/test/testing/method_call_assertions_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 
 class MethodCallAssertionsTest < ActiveSupport::TestCase
   class Level
diff --git a/activesupport/test/time_travel_test.rb b/activesupport/test/time_travel_test.rb
index c0d7eec129..7130397eef 100644
--- a/activesupport/test/time_travel_test.rb
+++ b/activesupport/test/time_travel_test.rb
@@ -1,9 +1,9 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/core_ext/date_time"
 require "active_support/core_ext/numeric/time"
-require "time_zone_test_helpers"
+require_relative "time_zone_test_helpers"
 
 class TimeTravelTest < ActiveSupport::TestCase
   include TimeZoneTestHelpers
diff --git a/activesupport/test/time_zone_test.rb b/activesupport/test/time_zone_test.rb
index 6ca3afd561..4b5f3dceee 100644
--- a/activesupport/test/time_zone_test.rb
+++ b/activesupport/test/time_zone_test.rb
@@ -1,8 +1,8 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/time"
-require "time_zone_test_helpers"
+require_relative "time_zone_test_helpers"
 require "yaml"
 
 class TimeZoneTest < ActiveSupport::TestCase
diff --git a/activesupport/test/transliterate_test.rb b/activesupport/test/transliterate_test.rb
index f13c5efa47..3d1fd6a893 100644
--- a/activesupport/test/transliterate_test.rb
+++ b/activesupport/test/transliterate_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/inflector/transliterate"
 
 class TransliterateTest < ActiveSupport::TestCase
diff --git a/activesupport/test/xml_mini/xml_mini_engine_test.rb b/activesupport/test/xml_mini/xml_mini_engine_test.rb
index 967e072411..a6f2086ae5 100644
--- a/activesupport/test/xml_mini/xml_mini_engine_test.rb
+++ b/activesupport/test/xml_mini/xml_mini_engine_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "../abstract_unit"
 require "active_support/xml_mini"
 require "active_support/core_ext/hash/conversions"
 
diff --git a/activesupport/test/xml_mini_test.rb b/activesupport/test/xml_mini_test.rb
index 73e7f40b0d..46ea0c8797 100644
--- a/activesupport/test/xml_mini_test.rb
+++ b/activesupport/test/xml_mini_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/xml_mini"
 require "active_support/builder"
 require "active_support/core_ext/hash"
diff --git a/activesupport/test/zeitwerk_inflector_test.rb b/activesupport/test/zeitwerk_inflector_test.rb
index d4d346dd56..afe1b7b0f5 100644
--- a/activesupport/test/zeitwerk_inflector_test.rb
+++ b/activesupport/test/zeitwerk_inflector_test.rb
@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-require "abstract_unit"
+require_relative "abstract_unit"
 require "active_support/dependencies/zeitwerk_integration"
 
 class ZeitwerkInflectorTest < ActiveSupport::TestCase