* 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, 25 insertions, 5 deletions

diff --git a/railties/lib/rails/commands/test/test_command.rb b/railties/lib/rails/commands/test/test_command.rb
index ca0b6c00fe..5852f51a62 100644
--- a/railties/lib/rails/commands/test/test_command.rb
+++ b/railties/lib/rails/commands/test/test_command.rb
@@ -1,21 +1,41 @@
 require_relative "../../command"
-require_relative "../../test_unit/minitest_plugin"
+require_relative "../../test_unit/runner"
 
 module Rails
   module Command
     class TestCommand < Base # :nodoc:
       no_commands do
         def help
-          perform # Hand over help printing to minitest.
+          require "optparse"
+          require "minitest/rails_plugin"
+
+          opts = OptionParser.new
+          opts.banner = "Usage: #{Rails::TestUnitReporter.executable} [options] [files or directories]"
+          opts.separator ""
+          opts.separator "You can run a single test by appending a line number to a filename:"
+          opts.separator ""
+          opts.separator "    #{Rails::TestUnitReporter.executable} test/models/user_test.rb:27"
+          opts.separator ""
+          opts.separator "You can run multiple files and directories at the same time:"
+          opts.separator ""
+          opts.separator "    #{Rails::TestUnitReporter.executable} test/controllers test/integration/login_test.rb"
+          opts.separator ""
+          opts.separator "By default test failures and errors are reported inline during a run."
+          opts.separator ""
+
+          opts.separator "Rails options:"
+          Rails::TestUnit::Runner.options(opts)
+          Minitest.plugin_rails_options(opts, {})
+
+          say opts
         end
       end
 
       def perform(*)
         $LOAD_PATH << Rails::Command.root.join("test").to_s
 
-        Minitest.run_via = :rails
-
-        require "active_support/testing/autorun"
+        Rails::TestUnit::Runner.parse_options(ARGV)
+        Rails::TestUnit::Runner.run(ARGV)
       end
     end
   end