RequestData type hint is dict, possibly should be Union[dict,str,bytes]

[arthur-tacca]

In _types.py we find this line:

RequestData = dict

which affects the type hint in httpx.Request:

class Request:
    def __init__(
        # ... some params omitted ...
        data: RequestData = None,
        # ... some params omitted ...
    ):

That means that forming a request with a string, or sending directly with one of the convenience functions, gives a type hint warning in a decent IDE:

already_stringified_data = json.dumps({"foo": "bar"})
client.send(Request(url, "POST", data=already_stringified_data))  # Warning: passing str instead of dict
client.post(url, data=already_stringified_data)  # Warning: passing str instead of dict

Looking at the implementation of Request (and PreparedRequest), it appears that using a string like this is valid usage. And it would be a pity, if you've already encoded your JSON for some other reason, to pass the original dict to httpx just so it can redundantly encode it.

If the above is a valid supported usage, I'd say that this is a bug. As the title says, RequestData ought to be Union[dict,str,bytes].

[adriangb]

Agreed!