Allow accessing all arguments by name on mock call objects

Feature or enhancement

Currently, call objects from the unittest.mock library only provide a tuple of positional arguments and a dictionary of keyword arguments passed to the function. It should be possible to enable accessing all arguments by name, not just the keyword arguments. The Signature object can help with this: https://docs.python.org/3/library/inspect.html#introspecting-callables-with-the-signature-object.

Pitch

For more robust and readable testing code.

首先阅读 unittest.mock 的 call 对象行为以及链接的 inspect.Signature 文档。确定如何在现有的位置参数元组和关键字参数字典之外按名称访问位置参数，然后定义预期的 API 和测试，以演示可读的命名参数访问方式。