Property based testing

[mgalloy]

Adding the ability to do property based testing to mgunit would help find more bugs.

To do property based tests, you would write methods that take parameters and don't start with "test." Then the actual test methods would call a routine, mgunit_proptest, that calls the test method with the given keywords.

For example, to test the routine mg_n_smallest:

function mg_n_smallest_ut::check_size, array=array, n=n
  compile_opt strictarr

  result = mg_n_smallest(arr, n)
  assert, n_elements(result) eq n
  return, 1
end

function mg_n_smallest_ut::test_size
  compile_opt strictarr

  mgunit_proptest, self, 'check_size', $
                   array=mgunit_array(mgunit_float()), $
                   n=mgunit_long(min_value=0)

  return, 1
end

pro mg_n_smallest_ut__define
  compile_opt strictarr

  define = { mg_n_smallest_ut, inherits MGutLibTestCase }
end

Other features:

• mgunit should write an explicit unit test when a property based test fails.