[pyupgrade] Don't introduce invalid syntax when upgrading old-style type aliases with parenthesized multiline values (UP040) (#16026)

crates/ruff_linter/resources/test/fixtures/pyupgrade/UP040.py

@@ -113,3 +113,18 @@ PositiveList = TypeAliasType(
         Annotated[T, Gt(0)],  # preserved comment
     ], type_params=(T,)
 )
+
+T: TypeAlias = (
+    int
+    | str
+)
+
+T: TypeAlias = ( # comment0
+    # comment1
+    int  # comment2
+    # comment3
+    | # comment4
+    # comment5
+    str  # comment6
+    # comment7
+) # comment8

crates/ruff_linter/src/rules/pyupgrade/rules/pep695/non_pep695_type_alias.rs

@@ -3,9 +3,9 @@ use itertools::Itertools;
 use ruff_diagnostics::{Applicability, Diagnostic, Edit, Fix, FixAvailability, Violation};
 use ruff_macros::{derive_message_formats, ViolationMetadata};
 use ruff_python_ast::name::Name;
-use ruff_python_ast::{
-    visitor::Visitor, Expr, ExprCall, ExprName, Keyword, StmtAnnAssign, StmtAssign,
-};
+use ruff_python_ast::parenthesize::parenthesized_range;
+use ruff_python_ast::visitor::Visitor;
+use ruff_python_ast::{Expr, ExprCall, ExprName, Keyword, StmtAnnAssign, StmtAssign, StmtRef};
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::checkers::ast::Checker;
@@ -183,8 +183,8 @@ pub(crate) fn non_pep695_type_alias_type(checker: &Checker, stmt: &StmtAssign) {
     };
 
     checker.report_diagnostic(create_diagnostic(
-        checker.source(),
-        stmt.range,
+        checker,
+        stmt.into(),
         &target_name.id,
         value,
         &vars,
@@ -243,8 +243,8 @@ pub(crate) fn non_pep695_type_alias(checker: &Checker, stmt: &StmtAnnAssign) {
     }
 
     checker.report_diagnostic(create_diagnostic(
-        checker.source(),
-        stmt.range(),
+        checker,
+        stmt.into(),
         name,
         value,
         &vars,
@@ -261,26 +261,30 @@ pub(crate) fn non_pep695_type_alias(checker: &Checker, stmt: &StmtAnnAssign) {
 
 /// Generate a [`Diagnostic`] for a non-PEP 695 type alias or type alias type.
 fn create_diagnostic(
-    source: &str,
-    stmt_range: TextRange,
+    checker: &Checker,
+    stmt: StmtRef,
     name: &Name,
     value: &Expr,
     type_vars: &[TypeVar],
     applicability: Applicability,
     type_alias_kind: TypeAliasKind,
 ) -> Diagnostic {
+    let source = checker.source();
+    let range_with_parentheses =
+        parenthesized_range(value.into(), stmt.into(), checker.comment_ranges(), source)
+            .unwrap_or(value.range());
     let content = format!(
         "type {name}{type_params} = {value}",
         type_params = DisplayTypeVars { type_vars, source },
-        value = &source[value.range()]
+        value = &source[range_with_parentheses]
     );
-    let edit = Edit::range_replacement(content, stmt_range);
+    let edit = Edit::range_replacement(content, stmt.range());
     Diagnostic::new(
         NonPEP695TypeAlias {
             name: name.to_string(),
             type_alias_kind,
         },
-        stmt_range,
+        stmt.range(),
     )
     .with_fix(Fix::applicable_edit(edit, applicability))
 }

crates/ruff_linter/src/rules/pyupgrade/snapshots/ruff_linter__rules__pyupgrade__tests__UP040.py.snap

@@ -417,6 +417,8 @@ UP040.py:111:1: UP040 [*] Type alias `PositiveList` uses `TypeAliasType` assignm
 114 | |     ], type_params=(T,)
 115 | | )
     | |_^ UP040
+116 |
+117 |   T: TypeAlias = (
     |
     = help: Use the `type` keyword
 
@@ -431,3 +433,57 @@ UP040.py:111:1: UP040 [*] Type alias `PositiveList` uses `TypeAliasType` assignm
 114     |-    ], type_params=(T,)
 115     |-)
     113 |+    ]
+116 114 | 
+117 115 | T: TypeAlias = (
+118 116 |     int
+
+UP040.py:117:1: UP040 [*] Type alias `T` uses `TypeAlias` annotation instead of the `type` keyword
+    |
+115 |   )
+116 |
+117 | / T: TypeAlias = (
+118 | |     int
+119 | |     | str
+120 | | )
+    | |_^ UP040
+121 |
+122 |   T: TypeAlias = ( # comment0
+    |
+    = help: Use the `type` keyword
+
+ℹ Unsafe fix
+114 114 |     ], type_params=(T,)
+115 115 | )
+116 116 | 
+117     |-T: TypeAlias = (
+    117 |+type T = (
+118 118 |     int
+119 119 |     | str
+120 120 | )
+
+UP040.py:122:1: UP040 [*] Type alias `T` uses `TypeAlias` annotation instead of the `type` keyword
+    |
+120 |   )
+121 |
+122 | / T: TypeAlias = ( # comment0
+123 | |     # comment1
+124 | |     int  # comment2
+125 | |     # comment3
+126 | |     | # comment4
+127 | |     # comment5
+128 | |     str  # comment6
+129 | |     # comment7
+130 | | ) # comment8
+    | |_^ UP040
+    |
+    = help: Use the `type` keyword
+
+ℹ Unsafe fix
+119 119 |     | str
+120 120 | )
+121 121 | 
+122     |-T: TypeAlias = ( # comment0
+    122 |+type T = ( # comment0
+123 123 |     # comment1
+124 124 |     int  # comment2
+125 125 |     # comment3