Create new mock request on each operation

[merll]

We have come across a few instances where views, filter backends etc. access properties of the request, for example the HTTP method. Since the mock request is only created on the first iteration, request path and method are identical for all following operations.

This PR changes the generator so that it creates a fresh mock request for each operation, avoiding further issues with introspection.

[tfranzel]

hi @merll as you saw this breaks the tests. pretty sure it also is not correct conceptually. if a versioned request comes in, the given version needs to be used for a correct schema. doing this potentially wipes out the given version.

your issue would most likely require a different resolution.

[codecov]

Codecov Report

Merging #250 (93a7102) into master (882ade7) will decrease coverage by 0.06%.
The diff coverage is 85.71%.

@@            Coverage Diff             @@
##           master     #250      +/-   ##
==========================================
- Coverage   98.32%   98.25%   -0.07%     
==========================================
  Files          53       53              
  Lines        4233     4366     +133     
==========================================
+ Hits         4162     4290     +128     
- Misses         71       76       +5     

Impacted Files	Coverage Δ
drf_spectacular/generators.py	96.66% <85.71%> (+0.11%)	⬆️
drf_spectacular/types.py	94.73% <0.00%> (-5.27%)	⬇️
tests/conftest.py	92.68% <0.00%> (-2.44%)	⬇️
tests/contrib/test_django_filters.py	98.75% <0.00%> (-1.25%)	⬇️
drf_spectacular/hooks.py	100.00% <0.00%> (ø)
tests/test_polymorphic.py	100.00% <0.00%> (ø)
tests/test_regressions.py	100.00% <0.00%> (ø)
drf_spectacular/settings.py	100.00% <0.00%> (ø)
drf_spectacular/serializers.py	100.00% <0.00%> (ø)
... and 5 more

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[merll]

I see. I pushed a change now that uses the incoming request if present, but still generates a new mock request on each iteration. That should fix the described side-effect without breaking existing behavior.

[tfranzel]

excellent! i suppose you are using the CLI for generation, because the issue should be the same for a real request (via the schema API endpoint). will probably also have to look into the other case.

interesting that this has not come up before.