Raising a HTTPUnauthorized caused error after upgrading from 3.6.2 to 3.7.4.post0

[teslafields]

🐞 Describe the bug

Raising a HTTPUnauthorized with a body="string" is giving an exception, as you can see in the traceback. This started to happen after I've upgraded from 3.6.2 to 3.7.4.post0. Looks to me that, as the body I return is str, it creates a StringPayload and still it tries to decode() it as it was bytes-like object

My piece of code that works in 3.6.2: raise web.HTTPUnauthorized(body='Not logged in')
Workaround to work in 3.7.4.post0: raise web.HTTPUnauthorized(body=b'Not logged in')

💡 To Reproduce

1. Try to raise a HTTPUnauthorized with a string body

📋 Logs/tracebacks

Traceback (most recent call last):
  File "aiohttp/web_protocol.py", line 422, in _handle_request
  File "aiohttp/web_app.py", line 499, in _handle
  File "aiohttp/web_middlewares.py", line 119, in impl
  File "aiohttp_session/__init__.py", line 172, in factory
  File "aiohttp_session/__init__.py", line 154, in factory
  File "http_server.py", line 1869, in route_get_info
  File "http_server.py", line 461, in validate_identity
aiohttp.web_exceptions.HTTPUnauthorized: Unauthorized

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "aiohttp/web_protocol.py", line 485, in start
  File "aiohttp/web_protocol.py", line 427, in _handle_request
  File "aiohttp/web_response.py", line 650, in text
AttributeError: 'StringPayload' object has no attribute 'decode'

📋 Your version of the Python

$ python --version
Python 3.8.0

📋 Your version of the aiohttp/yarl/multidict distributions

aiohttp==3.7.4.post0
aiohttp-jinja2==1.4.2
aiohttp-security==0.4.0
aiohttp-session==2.9.0
multidict==5.1.0
yarl==1.6.3

[webknjaz]

Sounds like a regression. The first step towards addressing this would be adding a regression test marked as xfail per https://pganssle-talks.github.io/xfail-lightning/. The PR should be sent against master and it can be merged with that xfail marker.
Then, somebody needs to bisect / track down what caused this change.

[paulefoe]

Looks like the change here
https://github.com/aio-libs/aiohttp/pull/3462/files#diff-549d85f88f5240e30a8a85dca61a84007be49b6d267f18bb85a6534a82c0f23eL85

UPD: link is not right, it was introduced earlier. I will continue to search a little bit later.

Here's reproducer:

from aiohttp import web
routes = web.RouteTableDef()
@routes.get('/', name='main')
async def hello(request):
    raise web.HTTPUnauthorized(body='Not logged in')


app = web.Application()
app.add_routes(routes)
web.run_app(app, port=8082)

Works in 3.6.3, does not work in 3.7.0

[webknjaz]

@paulefoe it's best to submit that as a regression test marked as xfail pointing to this issue in the "reason=" arg per https://pganssle-talks.github.io/xfail-lightning/

[webknjaz]

Alright, with a regression test in place, it's time to have this compatibility issue addressed.

[paulefoe]

I will be looking into it tomorrow

[paulefoe]

I think I found it, it's this change:

https://github.com/aio-libs/aiohttp/pull/4271/files#diff-2126b277e07e3fdd05e7a81da456accf24e5515a46c78c48a79db4eb166043e4R383-R386

In both 3.6.3 and 3.7.0 self._body inside text is a StringPayload, but previously there was no call to exc.text when returning a response.

StringPayload, however, is fairly easy to decode, we can do something like:

@property
def text(self) -> Optional[str]:
    if self._body is None:
        return None
    if isinstance(self._body, StringPayload):
        return self._body._value.decode(self._body.encoding)
    return self._body.decode(self.charset or "utf-8")

Although, then we should probably make value a public property inside Payload