def test_del_param_can_remove_valueless_parameters(self):
valueless = QueryString('abc=123&def&abc=456')
empty_valued = QueryString('abc=123&def=&abc=456')
assert valueless.del_param('def') == 'abc=123&abc=456'
assert empty_valued.del_param('def') == 'abc=123&abc=456'
def test_del_param_can_remove_anonymous_parameters(self):
s = QueryString('abc=123&=456&def=789')
assert s.del_param('') == 'abc=123&def=789'
def test_del_param_removes_all_instances_of_the_parameter_from_the_QueryString(self):
s = QueryString('abc=123&def=456&abc=789')
assert s.del_param('abc') == 'def=456'
assert s.del_param('def') == 'abc=123&abc=789'
