[`pyupgrade`] Fix false positive for `TypeVar` with default on Python <3.13 (`UP046`,`UP047`) (#21045)
## Summary
Type default for Type parameter was added in Python 3.13 (PEP 696).
`typing_extensions.TypeVar` backports the default argument to earlier
versions.
`UP046` & `UP047` were getting triggered when
`typing_extensions.TypeVar` with `default` argument was used on python
version < 3.13
It shouldn't be triggered for python version < 3.13
This commit fixes the bug by adding a python version check before
triggering them.
Fixes #20929.
## Test Plan
### Manual testing 1
As the issue author pointed out in
https://github.com/astral-sh/ruff/issues/20929#issuecomment-3413194511,
ran the following on `main` branch:
> % cargo run -p ruff -- check ../efax/ --target-version py312
--no-cache
<details><summary>Output</summary>
```zsh
Compiling ruff_linter v0.14.1 (/Users/prakhar/ruff/crates/ruff_linter)
Compiling ruff v0.14.1 (/Users/prakhar/ruff/crates/ruff)
Compiling ruff_graph v0.1.0 (/Users/prakhar/ruff/crates/ruff_graph)
Compiling ruff_workspace v0.0.0 (/Users/prakhar/ruff/crates/ruff_workspace)
Compiling ruff_server v0.2.2 (/Users/prakhar/ruff/crates/ruff_server)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 6.72s
Running `target/debug/ruff check ../efax/ --target-version py312 --no-cache`
UP046 Generic class `ExpectationParametrization` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/efax/_src/expectation_parametrization.py:17:48
|
17 | class ExpectationParametrization(Distribution, Generic[NP]):
| ^^^^^^^^^^^
18 | """The expectation parametrization of an exponential family distribution.
|
help: Use type parameters
UP046 Generic class `ExpToNat` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/efax/_src/mixins/exp_to_nat/exp_to_nat.py:27:68
|
26 | @dataclass
27 | class ExpToNat(ExpectationParametrization[NP], SimpleDistribution, Generic[NP]):
| ^^^^^^^^^^^
28 | """This mixin implements the conversion from expectation to natural parameters.
|
help: Use type parameters
UP046 Generic class `HasEntropyEP` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/efax/_src/mixins/has_entropy.py:25:20
|
23 | HasEntropy,
24 | JaxAbstractClass,
25 | Generic[NP]):
| ^^^^^^^^^^^
26 | @abstract_jit
27 | @abstractmethod
|
help: Use type parameters
UP046 Generic class `HasEntropyNP` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/efax/_src/mixins/has_entropy.py:64:20
|
62 | class HasEntropyNP(NaturalParametrization[EP],
63 | HasEntropy,
64 | Generic[EP]):
| ^^^^^^^^^^^
65 | @jit
66 | @final
|
help: Use type parameters
UP046 Generic class `NaturalParametrization` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/efax/_src/natural_parametrization.py:43:30
|
41 | class NaturalParametrization(Distribution,
42 | JaxAbstractClass,
43 | Generic[EP, Domain]):
| ^^^^^^^^^^^^^^^^^^^
44 | """The natural parametrization of an exponential family distribution.
|
help: Use type parameters
UP046 Generic class `Structure` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/efax/_src/structure/structure.py:31:17
|
30 | @dataclass
31 | class Structure(Generic[P]):
| ^^^^^^^^^^
32 | """This class generalizes the notion of type for Distribution objects.
|
help: Use type parameters
UP046 Generic class `DistributionInfo` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/efax/tests/distribution_info.py:20:24
|
20 | class DistributionInfo(Generic[NP, EP, Domain]):
| ^^^^^^^^^^^^^^^^^^^^^^^
21 | def __init__(self, dimensions: int = 1, safety: float = 0.0) -> None:
22 | super().__init__()
|
help: Use type parameters
Found 7 errors.
No fixes available (7 hidden fixes can be enabled with the `--unsafe-fixes` option).
```
</details>
Running it after the changes:
```zsh
ruff % cargo run -p ruff -- check ../efax/ --target-version py312 --no-cache
Compiling ruff_linter v0.14.1 (/Users/prakhar/ruff/crates/ruff_linter)
Compiling ruff v0.14.1 (/Users/prakhar/ruff/crates/ruff)
Compiling ruff_graph v0.1.0 (/Users/prakhar/ruff/crates/ruff_graph)
Compiling ruff_workspace v0.0.0 (/Users/prakhar/ruff/crates/ruff_workspace)
Compiling ruff_server v0.2.2 (/Users/prakhar/ruff/crates/ruff_server)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 7.86s
Running `target/debug/ruff check ../efax/ --target-version py312 --no-cache`
All checks passed!
```
---
### Manual testing 2
Ran the check on the following script (mainly to verify `UP047`):
```py
from __future__ import annotations
from typing import Generic
from typing_extensions import TypeVar
T = TypeVar("T", default=int)
def generic_function(var: T) -> T:
return var
Q = TypeVar("Q", default=str)
class GenericClass(Generic[Q]):
var: Q
```
On `main` branch:
> ruff % cargo run -p ruff -- check ~/up046.py --target-version py312
--preview --no-cache
<details><summary>Output</summary>
```zsh
Compiling ruff_linter v0.14.1 (/Users/prakhar/ruff/crates/ruff_linter)
Compiling ruff v0.14.1 (/Users/prakhar/ruff/crates/ruff)
Compiling ruff_graph v0.1.0 (/Users/prakhar/ruff/crates/ruff_graph)
Compiling ruff_workspace v0.0.0 (/Users/prakhar/ruff/crates/ruff_workspace)
Compiling ruff_server v0.2.2 (/Users/prakhar/ruff/crates/ruff_server)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 7.43s
Running `target/debug/ruff check /Users/prakhar/up046.py --target-version py312 --preview --no-cache`
UP047 Generic function `generic_function` should use type parameters
--> /Users/prakhar/up046.py:10:5
|
10 | def generic_function(var: T) -> T:
| ^^^^^^^^^^^^^^^^^^^^^^^^
11 | return var
|
help: Use type parameters
UP046 Generic class `GenericClass` uses `Generic` subclass instead of type parameters
--> /Users/prakhar/up046.py:17:20
|
17 | class GenericClass(Generic[Q]):
| ^^^^^^^^^^
18 | var: Q
|
help: Use type parameters
Found 2 errors.
No fixes available (2 hidden fixes can be enabled with the `--unsafe-fixes` option).
```
</details>
After the fix (this branch):
```zsh
ruff % cargo run -p ruff -- check ~/up046.py --target-version py312 --preview --no-cache
Compiling ruff_linter v0.14.1 (/Users/prakhar/ruff/crates/ruff_linter)
Compiling ruff v0.14.1 (/Users/prakhar/ruff/crates/ruff)
Compiling ruff_graph v0.1.0 (/Users/prakhar/ruff/crates/ruff_graph)
Compiling ruff_workspace v0.0.0 (/Users/prakhar/ruff/crates/ruff_workspace)
Compiling ruff_server v0.2.2 (/Users/prakhar/ruff/crates/ruff_server)
Finished `dev` profile [unoptimized + debuginfo] target(s) in 7.40s
Running `target/debug/ruff check /Users/prakhar/up046.py --target-version py312 --preview --no-cache`
All checks passed!
```
Signed-off-by: Prakhar Pratyush <prakhar1144@gmail.com>
ruff
10bda3df - [`pyupgrade`] Fix false positive for `TypeVar` with default on Python <3.13 (`UP046`,`UP047`) (#21045)
