class ActiveSupport::TestCase

def assert_nothing_raised(*args)

end
perform_service(param: 'no_exception')
assert_nothing_raised do

Passes if evaluated code in the yielded block raises no exception.

Assertion that the block should not raise an exception. 
def assert_nothing_raised(*args)
  if args.present?
    ActiveSupport::Deprecation.warn(
      "Passing arguments to assert_nothing_raised " \
      "is deprecated and will be removed in Rails 5.1.")
  end
  yield
end

def test_order

Defaults to +:random+.
Possible values are +:random+, +:parallel+, +:alpha+, +:sorted+.

ActiveSupport::TestCase.test_order # => :random

Returns the order in which test cases are run. 
def test_order
  ActiveSupport.test_order ||= :random
end

def test_order=(new_order)

* +:alpha+ (equivalent to +:sorted+)
* +:sorted+ (to run tests alphabetically by method name)
* +:parallel+ (to run tests in parallel)
* +:random+ (to run tests in random order)
Valid values are:

ActiveSupport::TestCase.test_order = :random # => :random

Sets the order in which test cases are run. 
def test_order=(new_order)
  ActiveSupport.test_order = new_order
end