Run tests in custom test folder in Rails 5+

When I want to run all model tests we do

rails test:models

If I similarly would like to run tests that sits in a folder called service_objects (in the test folder) - what would be the required steps?

With inspiration from multiple, sources I have tried the following in lib/tasks:

namespace :test do
  Rails::TestTask.new(classes: 'test:prepare') do |t|
    t.pattern = 'test/service_objects/**/*_test.rb'
  end
end

But running rails test:service_objects returns this error message:

NameError: uninitialized constant Rails::TestTask

Replace Rails::TestTask with Rails::TestUnit::Runner as shown in the file below, with the require path indicated at the top.

Then to run ONLY the tests in test/focused directory, you can call

rails test:focused

and to run ALL tests in the test directory EXCEPT those in test/long_running, you can call

rails test:without_long_running

Tested with Rails 5.1.6

The new Rails 5 test runner does have some really helpful features, but sometimes you still need a little more control.

# lib/tasks/test_tasks.rake

require "rails/test_unit/runner"

namespace :test do
  task :focused => "test:prepare" do
    $: << "test"
    test_files = FileList['test/focused/*_test.rb']
    Rails::TestUnit::Runner.run(test_files)
  end

  task :without_long_running_tests => "test:prepare" do
    $: << "test"
    test_files = FileList['test/**/*_test.rb'].exclude('test/long_running/**/*_test.rb')
    Rails::TestUnit::Runner.run(test_files)
  end
end

Credit should go to jonatack may 2015 post here: https://github.com/rails/rails/issues/19997

Update for Rails 7:

namespace :test do
  task :without_long_running_tests => "test:prepare" do
    if !Rails.env.test?
      system("rails test:without_long_running_tests RAILS_ENV=test")
    else
      $: << "test"
      test_files = FileList['test/**/*_test.rb'].exclude('test/long_running/**/*_test.rb')
      Rails::TestUnit::Runner.run(test_files)
    end
  end
end