Resolve queryset annotate types for expressions with static ClassVar#3221
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federicobond wants to merge 2 commits intotypeddjango:masterfrom
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Resolve queryset annotate types for expressions with static ClassVar#3221federicobond wants to merge 2 commits intotypeddjango:masterfrom
federicobond wants to merge 2 commits intotypeddjango:masterfrom
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This looks super cool! cc @UnknownPlatypus
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I'll check this this week, it looks promising ! |
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| # For now, we don't try to resolve the output_field of the field would be, but use Any. | ||
| # Try to resolve the output_field type for each expression. For expressions | ||
| # with a static ClassVar output_field (e.g. Count → IntegerField → int), |
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Could we use the return type of the property/cached_property when applicable ?
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Not sure what you mean, which property?
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I've added resolution via property return type in a separate commit.
Instead of always typing annotated fields as Any, resolve the concrete Python type when the expression has a static ClassVar output_field (e.g. Count → int, Exists → bool, Length → int, Now → datetime).
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Instead of always typing annotated fields as Any, resolve the concrete Python type when the expression has a static ClassVar output_field (e.g. Count → int, Exists → bool, Length → int, Now → datetime).
The current implementation introduces some unsoundness, since functions like
Lengthcan returnNonefor nullable fields. This is not the case forCountorExists, for example. Settingis_nullable=Truehere is theoretically safer but would make the types wrong in the other direction, and is more annoying in practice.The real solution is to query the Django runtime for the type of the requested field argument, but it introduces quite a bit of complexity, and I'm not sure if it's worth pursuing before agreeing this is a desirable feature.
For now, I'm happy to discuss and gather more feedback.