utils.py 文件源码

def is_middleware(func):
    """
    test whether it is a middleware
    :return: Boolean
    """
    args = list(inspect.signature(func).parameters.items())

    # if not inspect.isawaitable(func):
    #     raise UnknownMiddlewareException("middleware {} should be awaitable".format(func.__name__))

    if len(args) != 3:
        raise UnknownMiddlewareException("middleware {} should has 3 params named req, res and next".format(func.__name__))

    if args[0][0] != 'req':
        raise UnknownMiddlewareException("the first param's name of middleware {} should be req".format(func.__name__))

    if args[1][0] != 'res':
        raise UnknownMiddlewareException("the second param's name of middleware {} should be res".format(func.__name__))

    if args[2][0] != 'next':
        raise UnknownMiddlewareException("the third param's name of middleware {} should be next".format(func.__name__))

    return True