| import inspect | |
| import sys | |
| def make_decorator(test_case_generator): | |
| # `test_case_generator` is a callable that receives the source test class | |
| # (typically a subclass of unittest.TestCase) and returns an iterable of | |
| # generated test cases. | |
| # Each element of the iterable is a 3-element tuple: | |
| # [0] Generated class name | |
| # [1] Dict of members | |
| # [2] Method generator | |
| # The method generator is also a callable that receives an original test | |
| # method and returns a new test method. | |
| def f(cls): | |
| # The input is a bare test case | |
| module_name = cls.__module__ | |
| # Generate parameterized test cases out of the input test case. | |
| module = sys.modules[module_name] | |
| assert module.__name__ == module_name | |
| for cls_name, members, method_generator in test_case_generator(cls): | |
| _generate_case( | |
| cls, module, cls_name, members, method_generator) | |
| # Remove original base class | |
| return None | |
| return f | |
| def _generate_case(base, module, cls_name, mb, method_generator): | |
| members = mb.copy() | |
| base_methods = inspect.getmembers(base, predicate=inspect.isfunction) | |
| for name, value in base_methods: | |
| if not name.startswith('test_'): | |
| continue | |
| value = method_generator(value) | |
| # If the return value of method_generator is None, None is assigned | |
| # as the value of the test method and it is ignored by pytest. | |
| members[name] = value | |
| cls = type(cls_name, (base,), members) | |
| # Add new test class to module | |
| cls.__module__ = module.__name__ | |
| setattr(module, cls_name, cls) | |