From 5a1fde8fd262c95377489c850584edb03dd12dda Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Wed, 20 Dec 2023 09:26:05 -0500
Subject: [PATCH] Prefer Never to NoReturn in auto-typing

---
 .../src/rules/flake8_annotations/helpers.rs       | 15 +++++++++++----
 ...ake8_annotations__tests__auto_return_type.snap |  6 +++---
 2 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/crates/ruff_linter/src/rules/flake8_annotations/helpers.rs b/crates/ruff_linter/src/rules/flake8_annotations/helpers.rs
index baf316357da55..0ef1bcf262c0f 100644
--- a/crates/ruff_linter/src/rules/flake8_annotations/helpers.rs
+++ b/crates/ruff_linter/src/rules/flake8_annotations/helpers.rs
@@ -62,7 +62,7 @@ pub(crate) fn auto_return_type(function: &ast::StmtFunctionDef) -> Option<AutoPy
 
     // If every control flow path raises an exception, return `NoReturn`.
     if terminal == Some(Terminal::Raise) {
-        return Some(AutoPythonType::NoReturn);
+        return Some(AutoPythonType::Never);
     }
 
     // Determine the return type of the first `return` statement.
@@ -102,7 +102,7 @@ pub(crate) fn auto_return_type(function: &ast::StmtFunctionDef) -> Option<AutoPy
 
 #[derive(Debug)]
 pub(crate) enum AutoPythonType {
-    NoReturn,
+    Never,
     Atom(PythonType),
     Union(FxHashSet<PythonType>),
 }
@@ -120,10 +120,17 @@ impl AutoPythonType {
         target_version: PythonVersion,
     ) -> Option<(Expr, Vec<Edit>)> {
         match self {
-            AutoPythonType::NoReturn => {
+            AutoPythonType::Never => {
                 let (no_return_edit, binding) = importer
                     .get_or_import_symbol(
-                        &ImportRequest::import_from("typing", "NoReturn"),
+                        &ImportRequest::import_from(
+                            "typing",
+                            if target_version >= PythonVersion::Py311 {
+                                "Never"
+                            } else {
+                                "NoReturn"
+                            },
+                        ),
                         at,
                         semantic,
                     )
diff --git a/crates/ruff_linter/src/rules/flake8_annotations/snapshots/ruff_linter__rules__flake8_annotations__tests__auto_return_type.snap b/crates/ruff_linter/src/rules/flake8_annotations/snapshots/ruff_linter__rules__flake8_annotations__tests__auto_return_type.snap
index 1dc85efd74b0d..d374776949219 100644
--- a/crates/ruff_linter/src/rules/flake8_annotations/snapshots/ruff_linter__rules__flake8_annotations__tests__auto_return_type.snap
+++ b/crates/ruff_linter/src/rules/flake8_annotations/snapshots/ruff_linter__rules__flake8_annotations__tests__auto_return_type.snap
@@ -540,13 +540,13 @@ auto_return_type.py:203:5: ANN201 [*] Missing return type annotation for public
 204 |     if not x:
 205 |         raise ValueError
     |
-    = help: Add return type annotation: `NoReturn`
+    = help: Add return type annotation: `Never`
 
 ℹ Unsafe fix
 151 151 | 
 152 152 | import abc
 153 153 | from abc import abstractmethod
-    154 |+from typing import NoReturn
+    154 |+from typing import Never
 154 155 | 
 155 156 | 
 156 157 | class Foo(abc.ABC):
@@ -555,7 +555,7 @@ auto_return_type.py:203:5: ANN201 [*] Missing return type annotation for public
 201 202 | 
 202 203 | 
 203     |-def func(x: int):
-    204 |+def func(x: int) -> NoReturn:
+    204 |+def func(x: int) -> Never:
 204 205 |     if not x:
 205 206 |         raise ValueError
 206 207 |     else: