* Don't eagerly require Rails' minitest plugin.

By making the Rails minitest behave like a standard minitest plugin
we're much more likely to not break when people use other minitest
plugins. Like minitest-focus and pride.

To do this, we need to behave like minitest: require files up front
and then perform the plugin behavior via the at_exit hook.
This also saves us a fair bit of wrangling with test file loading.

Finally, since the environment and warnings options have to be applied
as early as possible, and since minitest loads plugins at_exit, they
have to be moved to the test command.

* Don't expect the root method.

It's likely this worked because we eagerly loaded the Rails minitest plugin
and that somehow defined a root method on `Rails`.

* Assign a backtrace to failed exceptions.

Otherwise Minitest pukes when attempting to filter the backtrace (which
Rails' backtrace cleaner then removes).

Means the exception message test has to be revised too.

This is likely caused by the rails minitest plugin now being loaded for
these tests and assigning a default backtrace cleaner.

1 files changed, 6 insertions, 3 deletions

diff --git a/tools/test.rb b/tools/test.rb
index 52e9c19198..774e4ec6c7 100644
--- a/tools/test.rb
+++ b/tools/test.rb
@@ -3,8 +3,10 @@ $: << File.expand_path("test", COMPONENT_ROOT)
 require "bundler"
 Bundler.setup
 
-require "rails/test_unit/minitest_plugin"
+require "rails/test_unit/runner"
+require "rails/test_unit/reporter"
 require "rails/test_unit/line_filtering"
+require "active_support"
 require "active_support/test_case"
 
 class << Rails
@@ -17,5 +19,6 @@ end
 
 ActiveSupport::TestCase.extend Rails::LineFiltering
 Rails::TestUnitReporter.executable = "bin/test"
-Minitest.run_via = :rails
-require "active_support/testing/autorun"
+
+Rails::TestUnit::Runner.parse_options(ARGV)
+Rails::TestUnit::Runner.run(ARGV)