class TestArgumentCoercer(unittest.TestCase):
def setUp(self):
self.lib = TestLibrary('ArgTypeCoercion', ['42', 'true'])
def test_coercion_in_constructor(self):
instance = self.lib.get_instance()
assert_equals(instance.myInt, 42)
assert_equals(instance.myBool, True)
def test_coercing_to_integer(self):
self._test_coercion(self._handler_named('intArgument'),
['1'], [1])
def test_coercing_to_boolean(self):
handler = self._handler_named('booleanArgument')
self._test_coercion(handler, ['True'], [True])
self._test_coercion(handler, ['FALSE'], [ False])
def test_coercing_to_real_number(self):
self._test_coercion(self._handler_named('doubleArgument'),
['1.42'], [1.42])
self._test_coercion(self._handler_named('floatArgument'),
['-9991.098'], [-9991.098])
def test_coercion_with_compatible_types(self):
self._test_coercion(self._handler_named('coercableKeywordWithCompatibleTypes'),
['9999', '-42', 'FaLsE', '31.31'],
[9999, -42, False, 31.31])
def test_arguments_that_are_not_strings_are_not_coerced(self):
self._test_coercion(self._handler_named('intArgument'),
[self.lib], [self.lib])
self._test_coercion(self._handler_named('booleanArgument'),
[42], [42])
def test_coercion_fails_with_reasonable_message(self):
exp_msg = 'Argument at position 1 cannot be coerced to %s.'
self._test_coercion_fails(self._handler_named('intArgument'),
exp_msg % 'integer')
self._test_coercion_fails(self._handler_named('booleanArgument'),
exp_msg % 'boolean')
self._test_coercion_fails(self._handler_named('floatArgument'),
exp_msg % 'floating point number')
def test_no_arg_no_coercion(self):
self._test_coercion(self._handler_named('noArgument'), [], [])
def test_coercing_multiple_arguments(self):
self._test_coercion(self._handler_named('coercableKeyword'),
['10.0', '42', 'tRUe'], [10.0, 42, True])
def test_coercion_is_not_done_with_conflicting_signatures(self):
self._test_coercion(self._handler_named('unCoercableKeyword'),
['True', '42'], ['True', '42'])
def test_coercable_and_uncoercable_args_in_same_kw(self):
self._test_coercion(self._handler_named('coercableAndUnCoercableArgs'),
['1', 'False', '-23', '0'], ['1', False, -23, '0'])
def _handler_named(self, name):
return self.lib.handlers[name]
def _test_coercion(self, handler, args, expected):
assert_equals(handler._arg_coercer.coerce(args, {}), expected)
def _test_coercion_fails(self, handler, expected_message):
assert_raises_with_msg(ValueError, expected_message,
handler._arg_coercer.coerce, ['invalid'], {})
