Preserve the case of username and password in URL.build

[tushar-balwani]

What do these changes do?

The new changes preserve casing of username and password when extracted from host in URL.build

>>> yarl.URL.build(scheme='httPS', host='usER:passWORD@hostNAME', path='/paTH')
URL('httPS://usER:passWORD@hostname/paTH')
>>> yarl.URL.build(scheme='httPS', host='usER:passWORD@hostNAME', path='/paTH').user
'usER'
>>> yarl.URL.build(scheme='httPS', host='usER:passWORD@hostNAME', path='/paTH').password
'passWORD'

Are there changes in behavior for the user?

No.

Related issue number

#880

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• Add a new news fragment into the CHANGES folder
  • name it <issue_id>.<type> (e.g. 588.bugfix)
  • 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.

[webknjaz]

This seems like a weird place to extract this data from.. Could you add more detail regarding the problem you're trying to address?

[webknjaz]

Looks like these are the same test. So I'd recommend using @pytest.mark.parametrize to fold it.

Also, I don't believe that scheme needs to be case-insensitive. Do you have any RFC reference that clarify this corner case?

[webknjaz]

Please, use the past tense and RST markup here.

[webknjaz]

Also, why this information would ever be a part of the host? I don't think the API should allow for it at all...

[mjpieters]

This is the wrong fix, as discussed in #880. The issue is that host should only accept a host string, not an authority string. Pass those to URL.build(authority=...) instead.

The right fix is to reject any gen-delims characters in the host value (provided it is not an IP address). Either by raising a deprecation warning first, or just going straight to raising ValueError.