Use typing_extensions.TypeAlias for PYI026 fixes on pre-3.10 (#6696)

Closes https://github.com/astral-sh/ruff/issues/6695.

crates/ruff/src/rules/flake8_pyi/mod.rs

@@ -30,46 +30,50 @@ mod tests {
     #[test_case(Rule::ComplexAssignmentInStub, Path::new("PYI017.pyi"))]
     #[test_case(Rule::ComplexIfStatementInStub, Path::new("PYI002.py"))]
     #[test_case(Rule::ComplexIfStatementInStub, Path::new("PYI002.pyi"))]
+    #[test_case(Rule::CustomTypeVarReturnType, Path::new("PYI019.py"))]
+    #[test_case(Rule::CustomTypeVarReturnType, Path::new("PYI019.pyi"))]
     #[test_case(Rule::DocstringInStub, Path::new("PYI021.py"))]
     #[test_case(Rule::DocstringInStub, Path::new("PYI021.pyi"))]
     #[test_case(Rule::DuplicateUnionMember, Path::new("PYI016.py"))]
     #[test_case(Rule::DuplicateUnionMember, Path::new("PYI016.pyi"))]
     #[test_case(Rule::EllipsisInNonEmptyClassBody, Path::new("PYI013.py"))]
     #[test_case(Rule::EllipsisInNonEmptyClassBody, Path::new("PYI013.pyi"))]
-    #[test_case(Rule::NonSelfReturnType, Path::new("PYI034.py"))]
+    #[test_case(Rule::FutureAnnotationsInStub, Path::new("PYI044.py"))]
-    #[test_case(Rule::NonSelfReturnType, Path::new("PYI034.pyi"))]
+    #[test_case(Rule::FutureAnnotationsInStub, Path::new("PYI044.pyi"))]
     #[test_case(Rule::IterMethodReturnIterable, Path::new("PYI045.py"))]
     #[test_case(Rule::IterMethodReturnIterable, Path::new("PYI045.pyi"))]
     #[test_case(Rule::NoReturnArgumentAnnotationInStub, Path::new("PYI050.py"))]
     #[test_case(Rule::NoReturnArgumentAnnotationInStub, Path::new("PYI050.pyi"))]
-    #[test_case(Rule::NumericLiteralTooLong, Path::new("PYI054.py"))]
-    #[test_case(Rule::NumericLiteralTooLong, Path::new("PYI054.pyi"))]
     #[test_case(Rule::NonEmptyStubBody, Path::new("PYI010.py"))]
     #[test_case(Rule::NonEmptyStubBody, Path::new("PYI010.pyi"))]
+    #[test_case(Rule::NonSelfReturnType, Path::new("PYI034.py"))]
+    #[test_case(Rule::NonSelfReturnType, Path::new("PYI034.pyi"))]
+    #[test_case(Rule::NumericLiteralTooLong, Path::new("PYI054.py"))]
+    #[test_case(Rule::NumericLiteralTooLong, Path::new("PYI054.pyi"))]
     #[test_case(Rule::PassInClassBody, Path::new("PYI012.py"))]
     #[test_case(Rule::PassInClassBody, Path::new("PYI012.pyi"))]
     #[test_case(Rule::PassStatementStubBody, Path::new("PYI009.py"))]
     #[test_case(Rule::PassStatementStubBody, Path::new("PYI009.pyi"))]
+    #[test_case(Rule::PatchVersionComparison, Path::new("PYI004.py"))]
+    #[test_case(Rule::PatchVersionComparison, Path::new("PYI004.pyi"))]
     #[test_case(Rule::QuotedAnnotationInStub, Path::new("PYI020.py"))]
     #[test_case(Rule::QuotedAnnotationInStub, Path::new("PYI020.pyi"))]
+    #[test_case(Rule::RedundantLiteralUnion, Path::new("PYI051.py"))]
+    #[test_case(Rule::RedundantLiteralUnion, Path::new("PYI051.pyi"))]
     #[test_case(Rule::RedundantNumericUnion, Path::new("PYI041.py"))]
     #[test_case(Rule::RedundantNumericUnion, Path::new("PYI041.pyi"))]
     #[test_case(Rule::SnakeCaseTypeAlias, Path::new("PYI042.py"))]
     #[test_case(Rule::SnakeCaseTypeAlias, Path::new("PYI042.pyi"))]
-    #[test_case(Rule::UnassignedSpecialVariableInStub, Path::new("PYI035.py"))]
-    #[test_case(Rule::UnassignedSpecialVariableInStub, Path::new("PYI035.pyi"))]
     #[test_case(Rule::StrOrReprDefinedInStub, Path::new("PYI029.py"))]
     #[test_case(Rule::StrOrReprDefinedInStub, Path::new("PYI029.pyi"))]
-    #[test_case(Rule::UnnecessaryLiteralUnion, Path::new("PYI030.py"))]
+    #[test_case(Rule::StringOrBytesTooLong, Path::new("PYI053.py"))]
-    #[test_case(Rule::UnnecessaryLiteralUnion, Path::new("PYI030.pyi"))]
+    #[test_case(Rule::StringOrBytesTooLong, Path::new("PYI053.pyi"))]
     #[test_case(Rule::StubBodyMultipleStatements, Path::new("PYI048.py"))]
     #[test_case(Rule::StubBodyMultipleStatements, Path::new("PYI048.pyi"))]
     #[test_case(Rule::TSuffixedTypeAlias, Path::new("PYI043.py"))]
     #[test_case(Rule::TSuffixedTypeAlias, Path::new("PYI043.pyi"))]
-    #[test_case(Rule::FutureAnnotationsInStub, Path::new("PYI044.py"))]
+    #[test_case(Rule::TypeAliasWithoutAnnotation, Path::new("PYI026.py"))]
-    #[test_case(Rule::FutureAnnotationsInStub, Path::new("PYI044.pyi"))]
+    #[test_case(Rule::TypeAliasWithoutAnnotation, Path::new("PYI026.pyi"))]
-    #[test_case(Rule::PatchVersionComparison, Path::new("PYI004.py"))]
-    #[test_case(Rule::PatchVersionComparison, Path::new("PYI004.pyi"))]
     #[test_case(Rule::TypeCommentInStub, Path::new("PYI033.py"))]
     #[test_case(Rule::TypeCommentInStub, Path::new("PYI033.pyi"))]
     #[test_case(Rule::TypedArgumentDefaultInStub, Path::new("PYI011.py"))]
@@ -78,8 +82,12 @@ mod tests {
     #[test_case(Rule::UnaliasedCollectionsAbcSetImport, Path::new("PYI025.pyi"))]
     #[test_case(Rule::UnannotatedAssignmentInStub, Path::new("PYI052.py"))]
     #[test_case(Rule::UnannotatedAssignmentInStub, Path::new("PYI052.pyi"))]
-    #[test_case(Rule::StringOrBytesTooLong, Path::new("PYI053.py"))]
+    #[test_case(Rule::UnassignedSpecialVariableInStub, Path::new("PYI035.py"))]
-    #[test_case(Rule::StringOrBytesTooLong, Path::new("PYI053.pyi"))]
+    #[test_case(Rule::UnassignedSpecialVariableInStub, Path::new("PYI035.pyi"))]
+    #[test_case(Rule::UnnecessaryLiteralUnion, Path::new("PYI030.py"))]
+    #[test_case(Rule::UnnecessaryLiteralUnion, Path::new("PYI030.pyi"))]
+    #[test_case(Rule::UnnecessaryTypeUnion, Path::new("PYI055.py"))]
+    #[test_case(Rule::UnnecessaryTypeUnion, Path::new("PYI055.pyi"))]
     #[test_case(Rule::UnprefixedTypeParam, Path::new("PYI001.py"))]
     #[test_case(Rule::UnprefixedTypeParam, Path::new("PYI001.pyi"))]
     #[test_case(Rule::UnrecognizedPlatformCheck, Path::new("PYI007.py"))]
@@ -88,24 +96,18 @@ mod tests {
     #[test_case(Rule::UnrecognizedPlatformName, Path::new("PYI008.pyi"))]
     #[test_case(Rule::UnrecognizedVersionInfoCheck, Path::new("PYI003.py"))]
     #[test_case(Rule::UnrecognizedVersionInfoCheck, Path::new("PYI003.pyi"))]
-    #[test_case(Rule::WrongTupleLengthVersionComparison, Path::new("PYI005.py"))]
-    #[test_case(Rule::WrongTupleLengthVersionComparison, Path::new("PYI005.pyi"))]
-    #[test_case(Rule::TypeAliasWithoutAnnotation, Path::new("PYI026.py"))]
-    #[test_case(Rule::TypeAliasWithoutAnnotation, Path::new("PYI026.pyi"))]
     #[test_case(Rule::UnsupportedMethodCallOnAll, Path::new("PYI056.py"))]
     #[test_case(Rule::UnsupportedMethodCallOnAll, Path::new("PYI056.pyi"))]
-    #[test_case(Rule::UnusedPrivateTypeVar, Path::new("PYI018.py"))]
-    #[test_case(Rule::UnusedPrivateTypeVar, Path::new("PYI018.pyi"))]
     #[test_case(Rule::UnusedPrivateProtocol, Path::new("PYI046.py"))]
     #[test_case(Rule::UnusedPrivateProtocol, Path::new("PYI046.pyi"))]
     #[test_case(Rule::UnusedPrivateTypeAlias, Path::new("PYI047.py"))]
     #[test_case(Rule::UnusedPrivateTypeAlias, Path::new("PYI047.pyi"))]
+    #[test_case(Rule::UnusedPrivateTypeVar, Path::new("PYI018.py"))]
+    #[test_case(Rule::UnusedPrivateTypeVar, Path::new("PYI018.pyi"))]
     #[test_case(Rule::UnusedPrivateTypedDict, Path::new("PYI049.py"))]
     #[test_case(Rule::UnusedPrivateTypedDict, Path::new("PYI049.pyi"))]
-    #[test_case(Rule::RedundantLiteralUnion, Path::new("PYI051.py"))]
+    #[test_case(Rule::WrongTupleLengthVersionComparison, Path::new("PYI005.py"))]
-    #[test_case(Rule::RedundantLiteralUnion, Path::new("PYI051.pyi"))]
+    #[test_case(Rule::WrongTupleLengthVersionComparison, Path::new("PYI005.pyi"))]
-    #[test_case(Rule::UnnecessaryTypeUnion, Path::new("PYI055.py"))]
-    #[test_case(Rule::UnnecessaryTypeUnion, Path::new("PYI055.pyi"))]
     fn rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());
         let diagnostics = test_path(
@@ -116,15 +118,15 @@ mod tests {
         Ok(())
     }
 
-    #[test_case(Path::new("PYI019.py"))]
+    #[test_case(Rule::TypeAliasWithoutAnnotation, Path::new("PYI026.py"))]
-    #[test_case(Path::new("PYI019.pyi"))]
+    #[test_case(Rule::TypeAliasWithoutAnnotation, Path::new("PYI026.pyi"))]
-    fn custom_type_var_return_type(path: &Path) -> Result<()> {
+    fn py38(rule_code: Rule, path: &Path) -> Result<()> {
-        let snapshot = format!("{}_{}", "PYI019", path.to_string_lossy());
+        let snapshot = format!("py38_{}_{}", rule_code.noqa_code(), path.to_string_lossy());
         let diagnostics = test_path(
             Path::new("flake8_pyi").join(path).as_path(),
             &settings::Settings {
-                target_version: PythonVersion::Py312,
+                target_version: PythonVersion::Py38,
-                ..settings::Settings::for_rules(vec![Rule::CustomTypeVarReturnType])
+                ..settings::Settings::for_rule(rule_code)
             },
         )?;
         assert_messages!(snapshot, diagnostics);

crates/ruff/src/rules/flake8_pyi/rules/mod.rs

@@ -21,6 +21,7 @@ pub(crate) use quoted_annotation_in_stub::*;
 pub(crate) use redundant_literal_union::*;
 pub(crate) use redundant_numeric_union::*;
 pub(crate) use simple_defaults::*;
+use std::fmt;
 pub(crate) use str_or_repr_defined_in_stub::*;
 pub(crate) use string_or_bytes_too_long::*;
 pub(crate) use stub_body_multiple_statements::*;
@@ -69,3 +70,26 @@ mod unrecognized_platform;
 mod unrecognized_version_info;
 mod unsupported_method_call_on_all;
 mod unused_private_type_definition;
+
+// TODO(charlie): Replace this with a common utility for selecting the appropriate source
+// module for a given `typing` member.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum TypingModule {
+    Typing,
+    TypingExtensions,
+}
+
+impl TypingModule {
+    fn as_str(self) -> &'static str {
+        match self {
+            TypingModule::Typing => "typing",
+            TypingModule::TypingExtensions => "typing_extensions",
+        }
+    }
+}
+
+impl fmt::Display for TypingModule {
+    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
+        fmt.write_str(self.as_str())
+    }
+}

crates/ruff/src/rules/flake8_pyi/rules/simple_defaults.rs

@@ -1,17 +1,18 @@
+use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic, Edit, Fix, Violation};
+use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast::call_path::CallPath;
 use ruff_python_ast::{
     self as ast, Arguments, Constant, Expr, Operator, ParameterWithDefault, Parameters, Ranged,
     Stmt, UnaryOp,
 };
-
-use ruff_diagnostics::{AlwaysAutofixableViolation, Diagnostic, Edit, Fix, Violation};
-use ruff_macros::{derive_message_formats, violation};
-use ruff_python_ast::call_path::CallPath;
 use ruff_python_semantic::{ScopeKind, SemanticModel};
 use ruff_source_file::Locator;
 
 use crate::checkers::ast::Checker;
 use crate::importer::ImportRequest;
 use crate::registry::AsRule;
+use crate::rules::flake8_pyi::rules::TypingModule;
+use crate::settings::types::PythonVersion;
 
 #[violation]
 pub struct TypedArgumentDefaultInStub;
@@ -124,6 +125,7 @@ impl Violation for UnassignedSpecialVariableInStub {
 /// ```
 #[violation]
 pub struct TypeAliasWithoutAnnotation {
+    module: TypingModule,
     name: String,
     value: String,
 }
@@ -131,12 +133,16 @@ pub struct TypeAliasWithoutAnnotation {
 impl AlwaysAutofixableViolation for TypeAliasWithoutAnnotation {
     #[derive_message_formats]
     fn message(&self) -> String {
-        let TypeAliasWithoutAnnotation { name, value } = self;
+        let TypeAliasWithoutAnnotation {
-        format!("Use `typing.TypeAlias` for type alias, e.g., `{name}: typing.TypeAlias = {value}`")
+            module,
+            name,
+            value,
+        } = self;
+        format!("Use `{module}.TypeAlias` for type alias, e.g., `{name}: TypeAlias = {value}`")
     }
 
     fn autofix_title(&self) -> String {
-        "Add `typing.TypeAlias` annotation".to_string()
+        "Add `TypeAlias` annotation".to_string()
     }
 }
 
@@ -606,7 +612,7 @@ pub(crate) fn unassigned_special_variable_in_stub(
     ));
 }
 
-/// PIY026
+/// PYI026
 pub(crate) fn type_alias_without_annotation(checker: &mut Checker, value: &Expr, targets: &[Expr]) {
     let [target] = targets else {
         return;
@@ -620,8 +626,15 @@ pub(crate) fn type_alias_without_annotation(checker: &mut Checker, value: &Expr,
         return;
     }
 
+    let module = if checker.settings.target_version >= PythonVersion::Py310 {
+        TypingModule::Typing
+    } else {
+        TypingModule::TypingExtensions
+    };
+
     let mut diagnostic = Diagnostic::new(
         TypeAliasWithoutAnnotation {
+            module,
             name: id.to_string(),
             value: checker.generator().expr(value),
         },
@@ -630,7 +643,7 @@ pub(crate) fn type_alias_without_annotation(checker: &mut Checker, value: &Expr,
     if checker.patch(diagnostic.kind.rule()) {
         diagnostic.try_set_fix(|| {
             let (import_edit, binding) = checker.importer().get_or_import_symbol(
-                &ImportRequest::import("typing", "TypeAlias"),
+                &ImportRequest::import(module.as_str(), "TypeAlias"),
                 target.start(),
                 checker.semantic(),
             )?;

crates/ruff/src/rules/flake8_pyi/snapshots/ruff__rules__flake8_pyi__tests__PYI026_PYI026.pyi.snap

@@ -1,7 +1,7 @@
 ---
 source: crates/ruff/src/rules/flake8_pyi/mod.rs
 ---
-PYI026.pyi:3:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `NewAny: typing.TypeAlias = Any`
+PYI026.pyi:3:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `NewAny: TypeAlias = Any`
   |
 1 | from typing import Literal, Any
 2 | 
@@ -10,7 +10,7 @@ PYI026.pyi:3:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `NewAny:
 4 | OptionalStr = typing.Optional[str]
 5 | Foo = Literal["foo"]
   |
-  = help: Add `typing.TypeAlias` annotation
+  = help: Add `TypeAlias` annotation
 
 ℹ Suggested fix
 1   |-from typing import Literal, Any
@@ -22,7 +22,7 @@ PYI026.pyi:3:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `NewAny:
 5 5 | Foo = Literal["foo"]
 6 6 | IntOrStr = int | str
 
-PYI026.pyi:4:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `OptionalStr: typing.TypeAlias = typing.Optional[str]`
+PYI026.pyi:4:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `OptionalStr: TypeAlias = typing.Optional[str]`
   |
 3 | NewAny = Any
 4 | OptionalStr = typing.Optional[str]
@@ -30,7 +30,7 @@ PYI026.pyi:4:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `Optiona
 5 | Foo = Literal["foo"]
 6 | IntOrStr = int | str
   |
-  = help: Add `typing.TypeAlias` annotation
+  = help: Add `TypeAlias` annotation
 
 ℹ Suggested fix
 1   |-from typing import Literal, Any
@@ -43,7 +43,7 @@ PYI026.pyi:4:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `Optiona
 6 6 | IntOrStr = int | str
 7 7 | AliasNone = None
 
-PYI026.pyi:5:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `Foo: typing.TypeAlias = Literal["foo"]`
+PYI026.pyi:5:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `Foo: TypeAlias = Literal["foo"]`
   |
 3 | NewAny = Any
 4 | OptionalStr = typing.Optional[str]
@@ -52,7 +52,7 @@ PYI026.pyi:5:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `Foo: ty
 6 | IntOrStr = int | str
 7 | AliasNone = None
   |
-  = help: Add `typing.TypeAlias` annotation
+  = help: Add `TypeAlias` annotation
 
 ℹ Suggested fix
 1   |-from typing import Literal, Any
@@ -66,7 +66,7 @@ PYI026.pyi:5:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `Foo: ty
 7 7 | AliasNone = None
 8 8 | 
 
-PYI026.pyi:6:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `IntOrStr: typing.TypeAlias = int | str`
+PYI026.pyi:6:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `IntOrStr: TypeAlias = int | str`
   |
 4 | OptionalStr = typing.Optional[str]
 5 | Foo = Literal["foo"]
@@ -74,7 +74,7 @@ PYI026.pyi:6:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `IntOrSt
   | ^^^^^^^^ PYI026
 7 | AliasNone = None
   |
-  = help: Add `typing.TypeAlias` annotation
+  = help: Add `TypeAlias` annotation
 
 ℹ Suggested fix
 1   |-from typing import Literal, Any
@@ -89,7 +89,7 @@ PYI026.pyi:6:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `IntOrSt
 8 8 | 
 9 9 | NewAny: typing.TypeAlias = Any
 
-PYI026.pyi:7:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `AliasNone: typing.TypeAlias = None`
+PYI026.pyi:7:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `AliasNone: TypeAlias = None`
   |
 5 | Foo = Literal["foo"]
 6 | IntOrStr = int | str
@@ -98,7 +98,7 @@ PYI026.pyi:7:1: PYI026 [*] Use `typing.TypeAlias` for type alias, e.g., `AliasNo
 8 | 
 9 | NewAny: typing.TypeAlias = Any
   |
-  = help: Add `typing.TypeAlias` annotation
+  = help: Add `TypeAlias` annotation
 
 ℹ Suggested fix
 1   |-from typing import Literal, Any

crates/ruff/src/rules/flake8_pyi/snapshots/ruff__rules__flake8_pyi__tests__py38_PYI026_PYI026.py.snap

@@ -0,0 +1,4 @@
+---
+source: crates/ruff/src/rules/flake8_pyi/mod.rs
+---
+

crates/ruff/src/rules/flake8_pyi/snapshots/ruff__rules__flake8_pyi__tests__py38_PYI026_PYI026.pyi.snap

@@ -0,0 +1,117 @@
+---
+source: crates/ruff/src/rules/flake8_pyi/mod.rs
+---
+PYI026.pyi:3:1: PYI026 [*] Use `typing_extensions.TypeAlias` for type alias, e.g., `NewAny: TypeAlias = Any`
+  |
+1 | from typing import Literal, Any
+2 | 
+3 | NewAny = Any
+  | ^^^^^^ PYI026
+4 | OptionalStr = typing.Optional[str]
+5 | Foo = Literal["foo"]
+  |
+  = help: Add `TypeAlias` annotation
+
+ℹ Suggested fix
+1 1 | from typing import Literal, Any
+  2 |+import typing_extensions
+2 3 | 
+3   |-NewAny = Any
+  4 |+NewAny: typing_extensions.TypeAlias = Any
+4 5 | OptionalStr = typing.Optional[str]
+5 6 | Foo = Literal["foo"]
+6 7 | IntOrStr = int | str
+
+PYI026.pyi:4:1: PYI026 [*] Use `typing_extensions.TypeAlias` for type alias, e.g., `OptionalStr: TypeAlias = typing.Optional[str]`
+  |
+3 | NewAny = Any
+4 | OptionalStr = typing.Optional[str]
+  | ^^^^^^^^^^^ PYI026
+5 | Foo = Literal["foo"]
+6 | IntOrStr = int | str
+  |
+  = help: Add `TypeAlias` annotation
+
+ℹ Suggested fix
+1 1 | from typing import Literal, Any
+  2 |+import typing_extensions
+2 3 | 
+3 4 | NewAny = Any
+4   |-OptionalStr = typing.Optional[str]
+  5 |+OptionalStr: typing_extensions.TypeAlias = typing.Optional[str]
+5 6 | Foo = Literal["foo"]
+6 7 | IntOrStr = int | str
+7 8 | AliasNone = None
+
+PYI026.pyi:5:1: PYI026 [*] Use `typing_extensions.TypeAlias` for type alias, e.g., `Foo: TypeAlias = Literal["foo"]`
+  |
+3 | NewAny = Any
+4 | OptionalStr = typing.Optional[str]
+5 | Foo = Literal["foo"]
+  | ^^^ PYI026
+6 | IntOrStr = int | str
+7 | AliasNone = None
+  |
+  = help: Add `TypeAlias` annotation
+
+ℹ Suggested fix
+1 1 | from typing import Literal, Any
+  2 |+import typing_extensions
+2 3 | 
+3 4 | NewAny = Any
+4 5 | OptionalStr = typing.Optional[str]
+5   |-Foo = Literal["foo"]
+  6 |+Foo: typing_extensions.TypeAlias = Literal["foo"]
+6 7 | IntOrStr = int | str
+7 8 | AliasNone = None
+8 9 | 
+
+PYI026.pyi:6:1: PYI026 [*] Use `typing_extensions.TypeAlias` for type alias, e.g., `IntOrStr: TypeAlias = int | str`
+  |
+4 | OptionalStr = typing.Optional[str]
+5 | Foo = Literal["foo"]
+6 | IntOrStr = int | str
+  | ^^^^^^^^ PYI026
+7 | AliasNone = None
+  |
+  = help: Add `TypeAlias` annotation
+
+ℹ Suggested fix
+1 1 | from typing import Literal, Any
+  2 |+import typing_extensions
+2 3 | 
+3 4 | NewAny = Any
+4 5 | OptionalStr = typing.Optional[str]
+5 6 | Foo = Literal["foo"]
+6   |-IntOrStr = int | str
+  7 |+IntOrStr: typing_extensions.TypeAlias = int | str
+7 8 | AliasNone = None
+8 9 | 
+9 10 | NewAny: typing.TypeAlias = Any
+
+PYI026.pyi:7:1: PYI026 [*] Use `typing_extensions.TypeAlias` for type alias, e.g., `AliasNone: TypeAlias = None`
+  |
+5 | Foo = Literal["foo"]
+6 | IntOrStr = int | str
+7 | AliasNone = None
+  | ^^^^^^^^^ PYI026
+8 | 
+9 | NewAny: typing.TypeAlias = Any
+  |
+  = help: Add `TypeAlias` annotation
+
+ℹ Suggested fix
+1 1 | from typing import Literal, Any
+  2 |+import typing_extensions
+2 3 | 
+3 4 | NewAny = Any
+4 5 | OptionalStr = typing.Optional[str]
+5 6 | Foo = Literal["foo"]
+6 7 | IntOrStr = int | str
+7   |-AliasNone = None
+  8 |+AliasNone: typing_extensions.TypeAlias = None
+8 9 | 
+9 10 | NewAny: typing.TypeAlias = Any
+10 11 | OptionalStr: TypeAlias = typing.Optional[str]
+
+