#11753 Improve the type annotation of Deferred.fromFuture
#11754
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Co-authored-by: Jean-Paul Calderone <exarkun@twistedmatrix.com>
src/twisted/internet/defer.py
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| @@ -1041,7 +1041,7 @@ def maybeSucceed(result: object) -> None: | |||
| return future | |||
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| @classmethod | |||
| def fromFuture(cls, future: Future) -> "Deferred[Any]": | |||
| def fromFuture(cls, future: Future[_T]) -> "Deferred[_T]": | |||
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It looks like Future is not generic on Python 3.7, so this fails.
I guess making it a string is the solution?
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I guess making it a string is the solution?
Probably yes.
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3.7 is no longer supported so should be fine now
for more information, see https://pre-commit.ci
…ier/twisted into babolivier/fromfuture_annotation
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please review |
| def fromFuture(cls, future: Future) -> "Deferred[Any]": | ||
| def fromFuture( | ||
| cls, future: "Future[_DeferredResultT]" | ||
| ) -> "Deferred[_DeferredResultT]": |
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Now I'm very confused about _DeferredResultT being contravariant... :/
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It's definitely wrong, but having spent some time trying to fix this now, it becomes clear that the real signatures for Deferred's methods are fiendishly complex, and this contravariance papers over some of the complexities (by accepting invalid types).
Trying to see if I can golf my way to a successful replacement that doesn't do that.
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@babolivier FYI, #11770 incorporates these commits, and will automatically close this PR as well if it's merged. |
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(Not blocking on this one, I'd just like to see a more comprehensive change to the annotations. If someone else comes along and merges it I'll happily integrate the commit.) |
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Just catching up, I see #11770 has been merged, so I'm closing this one. |
Scope and purpose
Fixes #11753
This PR improves the type annotation for
Deferred.fromFutureso that it's inferred from theFuture's return type.Contributor Checklist:
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The automated tests were updated.this PR is only changing a type annotation so I'm not sure there's any test to update - please advise if this isn't true.please review.Our bot will trigger the review process, by applying the pending review label
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