Enable autofix for unnecessary-paren-on-raise-exception (#2596)

crates/ruff/resources/test/fixtures/flake8_raise/RSE102.py

@@ -1,14 +1,33 @@
 try:
     y = 6 + "7"
 except TypeError:
-    raise ValueError()  # RSE102
+    # RSE102
+    raise ValueError()
 
 try:
     x = 1 / 0
 except ZeroDivisionError:
     raise
 
-raise TypeError()  # RSE102
+# RSE102
+raise TypeError()
+
+# RSE102
+raise TypeError ()
+
+# RSE102
+raise TypeError \
+    ()
+
+# RSE102
+raise TypeError(
+
+)
+
+# RSE102
+raise TypeError(
+    # Hello, world!
+)
 
 raise AssertionError
 

crates/ruff/src/ast/helpers.rs

@@ -755,6 +755,33 @@ pub fn count_trailing_lines(stmt: &Stmt, locator: &Locator) -> usize {
         .count()
 }
 
+/// Return the range of the first parenthesis pair after a given [`Location`].
+pub fn match_parens(start: Location, locator: &Locator) -> Option<Range> {
+    let contents = locator.slice_source_code_at(start);
+    let mut fix_start = None;
+    let mut fix_end = None;
+    let mut count: usize = 0;
+    for (start, tok, end) in lexer::make_tokenizer_located(contents, start).flatten() {
+        if matches!(tok, Tok::Lpar) {
+            if count == 0 {
+                fix_start = Some(start);
+            }
+            count += 1;
+        }
+        if matches!(tok, Tok::Rpar) {
+            count -= 1;
+            if count == 0 {
+                fix_end = Some(end);
+                break;
+            }
+        }
+    }
+    match (fix_start, fix_end) {
+        (Some(start), Some(end)) => Some(Range::new(start, end)),
+        _ => None,
+    }
+}
+
 /// Return the appropriate visual `Range` for any message that spans a `Stmt`.
 /// Specifically, this method returns the range of a function or class name,
 /// rather than that of the entire function or class body.

crates/ruff/src/rules/flake8_raise/rules/unnecessary_paren_on_raise_exception.rs

@@ -1,31 +1,47 @@
+use rustpython_ast::{Expr, ExprKind};
+
 use ruff_macros::derive_message_formats;
 
-use crate::ast::types::Range;
+use crate::ast::helpers::match_parens;
 use crate::checkers::ast::Checker;
 use crate::define_violation;
+use crate::fix::Fix;
 use crate::registry::Diagnostic;
-use crate::violation::Violation;
-use rustpython_ast::{Expr, ExprKind};
+use crate::violation::AlwaysAutofixableViolation;
 
 define_violation!(
     pub struct UnnecessaryParenOnRaiseException;
 );
-impl Violation for UnnecessaryParenOnRaiseException {
+impl AlwaysAutofixableViolation for UnnecessaryParenOnRaiseException {
     #[derive_message_formats]
     fn message(&self) -> String {
         format!("Unnecessary parentheses on raised exception")
     }
+
+    fn autofix_title(&self) -> String {
+        format!("Remove unnecessary parentheses")
+    }
 }
 
 /// RSE102
 pub fn unnecessary_paren_on_raise_exception(checker: &mut Checker, expr: &Expr) {
-    match &expr.node {
-        ExprKind::Call { args, keywords, .. } if args.is_empty() && keywords.is_empty() => {
-            checker.diagnostics.push(Diagnostic::new(
-                UnnecessaryParenOnRaiseException,
-                Range::from_located(expr),
-            ));
+    if let ExprKind::Call {
+        func,
+        args,
+        keywords,
+    } = &expr.node
+    {
+        if args.is_empty() && keywords.is_empty() {
+            let range = match_parens(func.end_location.unwrap(), checker.locator)
+                .expect("Expected call to include parentheses");
+            let mut diagnostic = Diagnostic::new(UnnecessaryParenOnRaiseException, range);
+            if checker.patch(diagnostic.kind.rule()) {
+                diagnostic.amend(Fix::deletion(
+                    func.end_location.unwrap(),
+                    range.end_location,
+                ));
+            }
+            checker.diagnostics.push(diagnostic);
         }
-        _ => (),
     }
 }

crates/ruff/src/rules/flake8_raise/snapshots/ruff__rules__flake8_raise__tests__unnecessary-paren-on-raise-exception_RSE102.py.snap

@@ -1,25 +1,113 @@
 ---
-source: src/rules/flake8_raise/mod.rs
+source: crates/ruff/src/rules/flake8_raise/mod.rs
 expression: diagnostics
 ---
 - kind:
     UnnecessaryParenOnRaiseException: ~
   location:
-    row: 4
-    column: 10
+    row: 5
+    column: 20
   end_location:
-    row: 4
+    row: 5
     column: 22
-  fix: ~
+  fix:
+    content:
+      - ""
+    location:
+      row: 5
+      column: 20
+    end_location:
+      row: 5
+      column: 22
   parent: ~
 - kind:
     UnnecessaryParenOnRaiseException: ~
   location:
-    row: 11
-    column: 6
+    row: 13
+    column: 15
   end_location:
-    row: 11
+    row: 13
     column: 17
-  fix: ~
+  fix:
+    content:
+      - ""
+    location:
+      row: 13
+      column: 15
+    end_location:
+      row: 13
+      column: 17
+  parent: ~
+- kind:
+    UnnecessaryParenOnRaiseException: ~
+  location:
+    row: 16
+    column: 16
+  end_location:
+    row: 16
+    column: 18
+  fix:
+    content:
+      - ""
+    location:
+      row: 16
+      column: 15
+    end_location:
+      row: 16
+      column: 18
+  parent: ~
+- kind:
+    UnnecessaryParenOnRaiseException: ~
+  location:
+    row: 20
+    column: 4
+  end_location:
+    row: 20
+    column: 6
+  fix:
+    content:
+      - ""
+    location:
+      row: 19
+      column: 15
+    end_location:
+      row: 20
+      column: 6
+  parent: ~
+- kind:
+    UnnecessaryParenOnRaiseException: ~
+  location:
+    row: 23
+    column: 15
+  end_location:
+    row: 25
+    column: 1
+  fix:
+    content:
+      - ""
+    location:
+      row: 23
+      column: 15
+    end_location:
+      row: 25
+      column: 1
+  parent: ~
+- kind:
+    UnnecessaryParenOnRaiseException: ~
+  location:
+    row: 28
+    column: 15
+  end_location:
+    row: 30
+    column: 1
+  fix:
+    content:
+      - ""
+    location:
+      row: 28
+      column: 15
+    end_location:
+      row: 30
+      column: 1
   parent: ~