fix(parser): Improve types for parser.py #419
Conversation
When attempting to use the parse function we noticed we were getting
error messages like:
Value of type variable "Model" of "parse" cannot be "Type[UserModel]"
Further investigation (using the example shown at
https://awslabs.github.io/aws-lambda-powertools-python/latest/utilities/parser/#envelopes)
showed that the types were incorrect for the example. The function
signatures were expecting an instance of `Model`, however the example
(and code) seemeed to expect a `Type[Model]`.
Similarly the signatures were expecting an optional instance of an
Envelope, but the code allows for either an instance or a Type.
Also, added a `TypeVar` for the decorator, specifying that the
event_parser` decorator returns the same type as the handler used.
Finally updated documentation on use of parser.
Codecov Report
@@ Coverage Diff @@
## develop #419 +/- ##
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Coverage 99.89% 99.89%
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Files 101 101
Lines 3978 3979 +1
Branches 198 198
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+ Hits 3974 3975 +1
Misses 1 1
Partials 3 3
Continue to review full report at Codecov.
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This is awesome @carlos-alberto! Thanks a lot for taking time to make your first contribution. @pcolazurdo in case you have some cycles to review. I'm working on the new event handler docs and can look into this next. Either way, this can make into this week's release |
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As @heitorlessa said, thank you for your contribution @carlos-alberto - The code changes seems ok to me, thanks for catching these, including the mistake in the documentation. |
@pcolazurdo 100%. It's something we wanted to do, including fixing all other MyPy issues across the code base. I hadn't done that for largely 2 reasons: 1/ Bandwidth, 2/ MyPy has some false positives and need to wrestle with config and learn how to "tame" it before adding in the CI, since that would block some contributions for the unfamiliar with it. Merging this now, thanks a lot to both of you! It'll be available in tomorrow's release. |
When attempting to use the parse function we noticed we were getting
error messages like:
Further investigation (using the example shown at
https://awslabs.github.io/aws-lambda-powertools-python/latest/utilities/parser/#envelopes)
showed that the types were incorrect for the example. The function
signatures were expecting an instance of
Model, however the example(and code) seemeed to expect a
Type[Model].Similarly the signatures were expecting an optional instance of an
Envelope, but the code allows for either an instance or a Type.
Finally, added a
TypeVarfor the decorator, specifying that theevent_parser` decorator returns the same type as the handler used.
Description of changes:
Fix type signatures of parser.py
Checklist
Breaking change checklist
RFC issue #:
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