Function parameterize

test/decorators.py:632–647

Add additional parameterization to a test function. This function create or adds to the `_parameterize` property of a function which is then expanded by the RunnerMeta metaclass into multiple separate test functions.

(func, parameters)

def parameterize(func, parameters):
  """Add additional parameterization to a test function.

  This function create or adds to the `_parameterize` property of a function
  which is then expanded by the RunnerMeta metaclass into multiple separate
  test functions.
  """
  prev = getattr(func, '_parameterize', None)
  assert not any(p.startswith('_') for p in parameters), 'test variant names should not start with _'
  if prev:
    # If we're parameterizing 2nd time, construct a cartesian product for various combinations.
    func._parameterize = {
      '_'.join(filter(None, [k1, k2])): v2 + v1 for (k1, v1), (k2, v2) in itertools.product(prev.items(), parameters.items())
    }
  else:
    func._parameterize = parameters


def parameterized(parameters):