diff --git a/activerecord/bin/test b/activerecord/bin/test
index 9ecf27ce67259..0c911085d76cf 100755
--- a/activerecord/bin/test
+++ b/activerecord/bin/test
@@ -8,7 +8,7 @@ if adapter_index
 end
 
 COMPONENT_ROOT = File.expand_path("..", __dir__)
-require_relative "../../tools/test"
+require_relative "../test/support/tools"
 
 module Minitest
   def self.plugin_active_record_options(opts, options)
diff --git a/activerecord/test/cases/adapters/postgresql/datatype_test.rb b/activerecord/test/cases/adapters/postgresql/datatype_test.rb
index ff9ac166a6f59..2cfa35760df6e 100644
--- a/activerecord/test/cases/adapters/postgresql/datatype_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/datatype_test.rb
@@ -7,7 +7,7 @@ class PostgresqlTime < ActiveRecord::Base
   # Declare attributes to get rid from deprecation warnings on ActiveRecord 6.1
   attribute :time_interval,        :string
   attribute :scaled_time_interval, :interval
-end if current_adapter?(:PostgreSQLAdapter)
+end
 
 class PostgresqlOid < ActiveRecord::Base
 end
diff --git a/activerecord/test/cases/adapters/postgresql/geometric_test.rb b/activerecord/test/cases/adapters/postgresql/geometric_test.rb
index 1e4f741f5fe5d..f312b6e23d7a0 100644
--- a/activerecord/test/cases/adapters/postgresql/geometric_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/geometric_test.rb
@@ -16,7 +16,7 @@ class PostgresqlPoint < ActiveRecord::Base
     attribute :legacy_x, :legacy_point
     attribute :legacy_y, :legacy_point
     attribute :legacy_z, :legacy_point
-  end if current_adapter?(:PostgreSQLAdapter)
+  end
 
   def setup
     @connection = ActiveRecord::Base.connection
diff --git a/activerecord/test/cases/adapters/postgresql/interval_test.rb b/activerecord/test/cases/adapters/postgresql/interval_test.rb
index fc134be532279..f6f53e68dae43 100644
--- a/activerecord/test/cases/adapters/postgresql/interval_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/interval_test.rb
@@ -12,7 +12,7 @@ class IntervalDataType < ActiveRecord::Base
     attribute :default_term, :interval
     attribute :all_terms,    :interval, array: true
     attribute :legacy_term,  :string
-  end if current_adapter?(:PostgreSQLAdapter)
+  end
 
   class DeprecatedIntervalDataType < ActiveRecord::Base; end
 
diff --git a/activerecord/test/support/tools.rb b/activerecord/test/support/tools.rb
new file mode 100644
index 0000000000000..e546dcaa8b6e5
--- /dev/null
+++ b/activerecord/test/support/tools.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+$: << File.expand_path("test", COMPONENT_ROOT)
+
+require "bundler/setup"
+
+require "rails/test_unit/runner"
+require "rails/test_unit/reporter"
+require "rails/test_unit/line_filtering"
+require "active_support"
+require "active_support/test_case"
+
+require "rake/testtask"
+Rails::TestUnit::Runner.singleton_class.prepend Module.new {
+   private
+     def list_tests(argv)
+       tests = super
+       tests.concat FileList["test/cases/adapters/#{adapter_name}/**/*_test.rb"]
+     end
+
+     def default_test_exclude_glob
+       ENV["DEFAULT_TEST_EXCLUDE"] || "test/cases/adapters/*/*_test.rb"
+     end
+
+     def adapter_name
+       ENV["ARCONN"] || "sqlite3"
+     end
+ }
+
+ActiveSupport::TestCase.extend Rails::LineFiltering
+Rails::TestUnitReporter.app_root = COMPONENT_ROOT
+Rails::TestUnitReporter.executable = "bin/test"
+
+Rails::TestUnit::Runner.parse_options(ARGV)
+Rails::TestUnit::Runner.run(ARGV)
diff --git a/railties/lib/rails/test_unit/runner.rb b/railties/lib/rails/test_unit/runner.rb
index ca6e52bf7a588..d6755c6ea8cfe 100644
--- a/railties/lib/rails/test_unit/runner.rb
+++ b/railties/lib/rails/test_unit/runner.rb
@@ -43,10 +43,7 @@ def run(argv = [])
         end
 
         def load_tests(argv)
-          patterns = extract_filters(argv)
-
-          tests = Rake::FileList[patterns.any? ? patterns : default_test_glob]
-          tests.exclude(default_test_exclude_glob) if patterns.empty?
+          tests = list_tests(argv)
           tests.to_a.each { |path| require File.expand_path(path) }
         end
 
@@ -94,6 +91,14 @@ def regexp_filter?(arg)
           def path_argument?(arg)
             %r"^[/\\]?\w+[/\\]".match?(arg)
           end
+
+          def list_tests(argv)
+            patterns = extract_filters(argv)
+
+            tests = Rake::FileList[patterns.any? ? patterns : default_test_glob]
+            tests.exclude(default_test_exclude_glob) if patterns.empty?
+            tests
+          end
       end
     end