$ gem install m

$ cat -n test/example_test.rb
 1  require 'test/unit'
 2
 3  class ExampleTest < Test::Unit::TestCase
 4    def test_apple
 5      assert_equal 1, 1
 6    end
 7
 8    def test_banana
 9      assert_equal 1, 1
10    end
11  end

$ m test/example_test.rb:4
Run options: -n /test_apple/
# Running tests:
.
Finished tests in 0.000525s, 1904.7619 tests/s, 1904.7619 assertions/s.
1 tests, 1 assertions, 0 failures, 0 errors, 0 skips

$ m test/example_test.rb:2
No tests found on line 2. Valid tests to run:
 test_apple: m test/examples/test_unit_example_test.rb:4
test_banana: m test/examples/test_unit_example_test.rb:8

$ m test/example_test.rb
Run options:
# Running tests:
..
Finished tests in 0.001293s, 1546.7904 tests/s, 3093.5808 assertions/s.
1 tests, 2 assertions, 0 failures, 0 errors, 0 skips

$ m -r test/models
"Searching provided directory for tests recursively"
Run options:
..
Finished in 3.459902s, 45.0880 runs/s, 87.5747 assertions/s.
156 tests, 303 assertions, 0 failures, 0 errors, 13 skips

$ m test/models -- --seed 1234
Run options: --seed 1234
..
Finished in 3.459902s, 45.0880 runs/s, 87.5747 assertions/s.
156 tests, 303 assertions, 0 failures, 0 errors, 13 skips

bundle exec rake test