False negative when using literal type in invariant slot #5321

erictraut · 2023-06-17T16:51:48Z

The following code should produce a type violation, but it doesn't.

from typing import Literal, TypeVar

T = TypeVar("T")

def func1(a: T, b: T) -> T:
    return a

def func2() -> None:
    foo_list: list[Literal["foo"]] = ["foo"]
    x = func1(foo_list, [""])
    x.append("not foo")
    print(foo_list)

func2()

…he same TypeVar in an invariant context. This addresses #5321.

…he same TypeVar in an invariant context. This addresses #5321. (#5323) Co-authored-by: Eric Traut <[email protected]>

erictraut · 2023-06-17T21:20:08Z

This will be addressed in the next release.

commit 63f5658 Author: Erik De Bonte <[email protected]> Date: Tue Jun 20 10:50:18 2023 -0700 Support PEP 712's new attribute assignment conversion (microsoft#5343) commit 9cbe8c0 Author: Eric Traut <[email protected]> Date: Tue Jun 20 09:17:40 2023 -0700 Fixed a bug that caused an incorrect false positive error for an `assert_type` call involving a `Callable[[], X]` type. Pyright was generating a signature with a positional-only separator in this case. This addresses python/typeshed#10325 (comment). (microsoft#5345) Co-authored-by: Eric Traut <[email protected]> commit d12ad6e Author: Eric Traut <[email protected]> Date: Mon Jun 19 23:59:08 2023 -0700 Updated typeshed stubs to the latest version. commit eff69f5 Author: Eric Traut <[email protected]> Date: Mon Jun 19 22:35:56 2023 -0700 Fixed a bug that caused incorrect type inference for parameters in unannotated methods within child classes who derive from a generic parent class. This addresses a bug reported on stack overflow: https://stackoverflow.com/questions/76466874/trouble-specifying-type-parameter-when-inheriting-from-generic-class. commit 43c5fae Author: Eric Traut <[email protected]> Date: Mon Jun 19 20:17:00 2023 -0700 Finished cleanup of test cases. commit b0d4080 Author: Eric Traut <[email protected]> Date: Mon Jun 19 19:15:53 2023 -0700 Next batch of test case cleanup. commit efea9b9 Author: Eric Traut <[email protected]> Date: Mon Jun 19 18:26:49 2023 -0700 Changed behavior of non-ClassVar variables within a protocol definition. Previously, an error was reported when such variables were accessed from the class (as opposed to an instance of the class). Mypy (which was the reference implementation for PEP 544) does not report an error here. This addresses microsoft/pylance-release#4389. commit 5568b4d Author: Eric Traut <[email protected]> Date: Mon Jun 19 18:00:31 2023 -0700 Enhanced command-line version of pyright to allow file or directory names to be passed via stdin if `-` option is used in the command line. This addresses microsoft#5342. commit cd257f7 Author: Eric Traut <[email protected]> Date: Mon Jun 19 15:38:13 2023 -0700 Next batch of test case cleanup. commit 0c5c7b6 Author: Eric Traut <[email protected]> Date: Mon Jun 19 14:23:50 2023 -0700 Next batch of text case cleanup. commit 899799d Author: Eric Traut <[email protected]> Date: Mon Jun 19 13:33:41 2023 -0700 Finished cleaning up "genericTypesX.py" test files. commit 1111f1b Author: Eric Traut <[email protected]> Date: Mon Jun 19 11:49:56 2023 -0700 Started to untangle the hairball related to the "genericTypesX.py" test cases. commit 67394ad Author: Eric Traut <[email protected]> Date: Mon Jun 19 10:21:36 2023 -0700 Continued cleanup of test cases. commit 96e03aa Author: Eric Traut <[email protected]> Date: Mon Jun 19 09:39:09 2023 -0700 Did a cleanup pass for the dataclass test cases. Renamed and reordered test cases for maintainability. commit b7df200 Author: Eric Traut <[email protected]> Date: Mon Jun 19 08:20:54 2023 -0700 Fixed bug that resulted in a false positive error when defining a new type alias using the `TypeAliasType` constructor that defines no new type parameters but references an outer-scoped type parameter in the type alias definition. This addresses microsoft#5341. commit d816d00 Author: Eric Traut <[email protected]> Date: Mon Jun 19 00:00:07 2023 -0700 Started to do a pass over the test cases to make them more consistent. commit 23bcbce Author: Eric Traut <[email protected]> Date: Sun Jun 18 17:42:25 2023 -0700 Fixed bug in code flow engine that led to incorrect type evaluation of a variable in a nested loop. This addresses https://github.com/microsoft/pylance-release/issues/4509. commit 056415f Author: Eric Traut <[email protected]> Date: Sun Jun 18 16:40:00 2023 -0700 Fixed a bug in the control flow debugging code that prints the control flow graph. It was not correctly handling one of the node types which led to incomplete graphs. commit 643bb1d Author: Eric Traut <[email protected]> Date: Sun Jun 18 13:20:49 2023 -0700 Improved type inference for lambdas in the case where a parameter includes a default value and the expected type doesn't include that parameter. This improvement was suggested in the [mypy issue tracker](python/mypy#15459). (microsoft#5337) Co-authored-by: Eric Traut <[email protected]> commit 8ce23eb Author: Eric Traut <[email protected]> Date: Sun Jun 18 12:55:22 2023 -0700 Improved `reportUnnecessaryCast` so it works with types other than cl… (microsoft#5336) Improved `reportUnnecessaryCast` so it works with types other than class instances. This addresses microsoft#5333. commit 52c8cac Author: Eric Traut <[email protected]> Date: Sun Jun 18 12:41:24 2023 -0700 Changed type printer (the component that renders types into text) to use the lowercase `type[x]` instead of `Type[x]`. It has now been four years since PEP 585 deprecated the use of the upper-case version, so most developers should be getting comfortable with the lowercase version at this point. commit e3080b1 Author: Eric Traut <[email protected]> Date: Sun Jun 18 10:15:58 2023 -0700 Fixed a bug that led to a false positive error under certain circumstances when a literal type argument was used in conjunction with a protocol that used a covariant type parameter and an implementation of that protocol that used an invariant type parameter. This addresses microsoft#5282. (microsoft#5332) Co-authored-by: Eric Traut <[email protected]> commit 2b0f8d2 Author: Eric Traut <[email protected]> Date: Sun Jun 18 09:46:18 2023 -0700 Improved hover text to display the calculated variance for a PEP 695-style class-scoped type variable when the user hovers over the type parameter in the type param list. commit 02b7769 Author: Eric Traut <[email protected]> Date: Sun Jun 18 00:17:53 2023 -0700 Fixed a false positive error arising from the use of a binary expression for a base class in a class declaration statement. This addresses microsoft#5326. (microsoft#5331) Co-authored-by: Eric Traut <[email protected]> commit 2de35e3 Author: Eric Traut <[email protected]> Date: Sun Jun 18 00:00:06 2023 -0700 Added documentation about higher-order functions. commit 42a37f4 Author: Eric Traut <[email protected]> Date: Sat Jun 17 23:38:50 2023 -0700 Re-enabled a test case that was previously disabled because it was broken. commit 7ea11a1 Author: Eric Traut <[email protected]> Date: Sat Jun 17 23:17:32 2023 -0700 Minor code cleanup — rename constant for clarity and refactor validation function. No functional change. commit 53cb3f9 Author: Eric Traut <[email protected]> Date: Sat Jun 17 23:00:49 2023 -0700 Improved consistency of parameter ordering internally to type evaluator. No functional change. commit 9bf8231 Author: Eric Traut <[email protected]> Date: Sat Jun 17 22:48:18 2023 -0700 Fixed a bug that led to incorrect type evaluation when passing a generic class (with a constructor that includes class-scoped TypeVars) as an argument for a callable parameter. The class was being specialized prematurely (with type arguments set to `Unknown`) before the constraint solver was able to solve the higher-order function's type variables. This addresses microsoft#5324. (microsoft#5328) Co-authored-by: Eric Traut <[email protected]> commit 47cd514 Author: Eric Traut <[email protected]> Date: Sat Jun 17 22:21:52 2023 -0700 Changed auto-variance algorithm to ignore `__new__` and `__init__` methods for purposes of calculating the variance of a TypeVar. This mirrors the behavior of mypy. (microsoft#5327) Co-authored-by: Eric Traut <[email protected]> commit 3021b9c Author: Eric Traut <[email protected]> Date: Sat Jun 17 21:52:57 2023 -0700 Minor code cleanup — removed dead code and converted lambda to function. No functional change. commit 327ce37 Author: Eric Traut <[email protected]> Date: Sat Jun 17 20:30:36 2023 -0700 Added test case for microsoft#5027. commit 0559382 Author: Eric Traut <[email protected]> Date: Sat Jun 17 14:19:12 2023 -0700 Fixed false negative when a literal and non-literal are assigned to the same TypeVar in an invariant context. This addresses microsoft#5321. (microsoft#5323) Co-authored-by: Eric Traut <[email protected]> commit 2829429 Author: Eric Traut <[email protected]> Date: Sat Jun 17 12:33:13 2023 -0700 Fixed bug that led to an incorrect type evaluation for nested call expressions where an inner call expression used a ParamSpec. This addresses microsoft#5281. (microsoft#5322) Co-authored-by: Eric Traut <[email protected]>

erictraut · 2023-06-21T01:50:40Z

This is included in pyright 1.1.315, which I just published. It will also be included in this week's insiders release of pylance.

This worked in Pyright 1.1.314, but not in 1.1.315 or 1.1.316. The type of service_ports is List[Tuple[str, Literal[3000], Literal[3000]]], which doesn't type check as List[Tuple[str, int, int]] -- which is very unintuitive, but oh well. I believe this is by design, see microsoft/pyright#5366 and https://microsoft.github.io/pyright/#/type-inference?id=tuple-expressions The Pyright fixes were probably one of microsoft/pyright#5321 or microsoft/pyright#5323

* Lock Pyright version to fix CI flakiness on canonical/operator See https://github.com/canonical/operator/actions/runs/5384117730/jobs/9771655581?pr=957 * Fix type checking issue with service_ports This worked in Pyright 1.1.314, but not in 1.1.315 or 1.1.316. The type of service_ports is List[Tuple[str, Literal[3000], Literal[3000]]], which doesn't type check as List[Tuple[str, int, int]] -- which is very unintuitive, but oh well. I believe this is by design, see microsoft/pyright#5366 and https://microsoft.github.io/pyright/#/type-inference?id=tuple-expressions The Pyright fixes were probably one of microsoft/pyright#5321 or microsoft/pyright#5323

erictraut added the bug Something isn't working label Jun 17, 2023

erictraut pushed a commit that referenced this issue Jun 17, 2023

Fixed false negative when a literal and non-literal are assigned to t…

629ee2d

…he same TypeVar in an invariant context. This addresses #5321.

erictraut mentioned this issue Jun 17, 2023

Fixed false negative when a literal and non-literal are assigned to t… #5323

Merged

erictraut added a commit that referenced this issue Jun 17, 2023

Fixed false negative when a literal and non-literal are assigned to t…

0559382

…he same TypeVar in an invariant context. This addresses #5321. (#5323) Co-authored-by: Eric Traut <[email protected]>

erictraut added the addressed in next version Issue is fixed and will appear in next published version label Jun 17, 2023

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erictraut closed this as completed Jun 21, 2023

Vegemash mentioned this issue Jun 22, 2023

Automatically typed Literal strings in tuples in lists cause invariance errors #5366

Closed

benhoyt mentioned this issue Jun 27, 2023

Lock Pyright version to fix CI flakiness on canonical/operator canonical/grafana-k8s-operator#223

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False negative when using literal type in invariant slot #5321

False negative when using literal type in invariant slot #5321

erictraut commented Jun 17, 2023

erictraut commented Jun 17, 2023

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erictraut commented Jun 21, 2023

False negative when using literal type in invariant slot #5321

False negative when using literal type in invariant slot #5321

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erictraut commented Jun 17, 2023

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