Raise ContentTypeError by json() when headers does not …

[pfreixes]

What do these changes do?

Basically, avoid having a nocive fall back as the following one

try:
    resp = await req.json()
except ClieintResponseError:
    logging.warning("Invalid content-type")
    resp = loads(await req.read())

The ClieintResponseError can be raised by many reasons, and the case presented the fallback can be misleading having as a result twice ClieintResponseError because the source of the problem wasn't related to the content type.

With an ad-hoc exception, the client can code a more specific fallback case taking into account the differents source of problems with a cleaner interface, for example:

try:
    resp = await req.json()
except ContentTypeError:
    logging.warning("Invalid content-type by servcie ....")
    resp = loads(await req.read())
except ClieintResponseError:
    logging.exception("something went wrong")
    raise

Thanks to the current json() implementation once we have had a ContentTypeError exception is not possible to have a ClieintResponseError. Therefore, the developer can handle the errors as the previous example.

For backward compatibility the ContentTypeError inherits from ClieintResponseError.

Are there changes in behavior for the user?

No

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• If you provide code modification, please add yourself to CONTRIBUTORS.txt
  • The format is <Name> <Surname>.
  • Please keep alphabetical order, the file is sorted by names.
• Add a new news fragment into the changes folder
  • name it <issue_id>.<type> for example (588.bug)
  • if you don't have an issue_id change it to the pr id after creating the pr
  • ensure type is one of the following:
    • .feature: Signifying a new feature.
    • .bugfix: Signifying a bug fix.
    • .doc: Signifying a documentation improvement.
    • .removal: Signifying a deprecation or removal of public API.
    • .misc: A ticket has been closed, but it is not of interest to users.
  • Make sure to use full sentences with correct case and punctuation, for example: "Fix issue with non-ascii contents in doctest text files."

[codecov-io]

Codecov Report

Merging #2136 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2136      +/-   ##
==========================================
+ Coverage   97.07%   97.07%   +<.01%     
==========================================
  Files          38       38              
  Lines        7723     7728       +5     
  Branches     1346     1347       +1     
==========================================
+ Hits         7497     7502       +5     
  Misses        102      102              
  Partials      124      124

Impacted Files	Coverage Δ
aiohttp/client_exceptions.py	100% <100%> (ø)	⬆️
aiohttp/client_reqrep.py	97.19% <100%> (ø)	⬆️
tests/autobahn/client.py	96.84% <0%> (ø)	⬆️
aiohttp/web_urldispatcher.py	99.42% <0%> (ø)	⬆️
aiohttp/web.py	99.65% <0%> (ø)	⬆️
aiohttp/test_utils.py	98.6% <0%> (ø)	⬆️
aiohttp/web_request.py	98.94% <0%> (+0.01%)	⬆️

---

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[asvetlov]

The intention is pretty clean but ClientResponseContentTypeError is 30 chars long!
Please invite shorter name.

[pfreixes]

Exception name changed to ContentTypeError

[asvetlov]

Thanks!

[lock]

This thread has been automatically locked since there has not been
any recent activity after it was closed. Please open a new issue for
related bugs.

If you feel like there's important points made in this discussion,
please include those exceprts into that new issue.