[ruff] Needless else clause (RUF047) (#15051)

Co-authored-by: Micha Reiser <micha@reiser.io>

crates/ruff_linter/resources/test/fixtures/ruff/RUF047_for.py

@@ -0,0 +1,49 @@
+### Errors
+
+for _ in range(0):
+    loop_body_is_not_checked()
+    break
+else:
+    pass
+
+
+for this in comment:
+    belongs_to()  # `for`
+else:
+    ...
+
+
+for of in course():
+    this()
+else:
+    ...
+# this comment does not belong to the else
+
+
+### No errors
+
+for this in second_comment:
+    belongs()  # to
+# `else`
+else:
+    pass
+
+
+for _and in so:
+    does()
+# this
+else:
+    pass
+
+
+for of in course():
+    this()
+else:
+    ...  # too
+
+
+for of in course():
+    this()
+else:
+    ...
+    # too

crates/ruff_linter/resources/test/fixtures/ruff/RUF047_if.py

@@ -0,0 +1,84 @@
+### Errors
+
+if False:
+    condition_is_not_evaluated()
+else:
+    pass
+
+
+if this_comment():
+    belongs_to()  # `if`
+else:
+    ...
+
+
+if elif_is():
+    treated()
+elif the_same():
+    as_if()
+else:
+    pass
+
+
+if this_second_comment():
+    belongs()  # to
+      # `if`
+else:
+    pass
+
+if this_second_comment():
+    belongs()  # to
+    # `if`
+else:
+    pass
+
+
+if of_course():
+    this()
+else:
+    ...
+# this comment doesn't belong to the if
+
+
+if of_course: this()
+else: ...
+
+
+if of_course:
+    this() # comment
+else: ...
+
+
+def nested():
+    if a:
+        b()
+    else:
+        ...
+
+
+### No errors
+
+
+if this_second_comment():
+    belongs()  # to
+# `else`
+else:
+    pass
+
+
+if of_course():
+    this()
+else:
+    ...  # too
+
+
+if of_course():
+    this()
+else:
+    ...
+    # comment
+
+
+if of_course:
+    this() # comment
+else: ...  # trailing

crates/ruff_linter/resources/test/fixtures/ruff/RUF047_try.py

@@ -0,0 +1,76 @@
+### Errors
+
+try:
+    raise try_body_is_not_checked()
+except:
+    pass
+else:
+    pass
+
+
+try:
+    this()
+except comment:
+    belongs()
+except:
+    to()  # `except`
+else:
+    ...
+
+
+try:
+    of_course()
+except:
+    this()
+else:
+    ...
+# This comment belongs to finally
+finally:
+    pass
+
+
+try:
+    of_course()
+except:
+    this()
+else:
+    ...
+# This comment belongs to the statement coming after the else
+
+
+### No errors
+
+try:
+    this()
+except (second, comment):
+    belongs()  # to
+# `else`
+else:
+    pass
+
+
+try:
+    and_so()
+except:
+    does()
+# this
+else:
+    ...
+
+
+try:
+    of_course()
+except:
+    this()
+else:
+    ...  # too
+
+try:
+    of_course()
+except:
+    this()
+else:
+    ...
+    # This comment belongs to else
+finally:
+    pass

crates/ruff_linter/resources/test/fixtures/ruff/RUF047_while.py

@@ -0,0 +1,49 @@
+### No errors
+
+while True:
+    loop_body_is_not_checked()
+    break
+else:
+    pass
+
+
+while this_comment:
+    belongs_to()  # `for`
+else:
+    ...
+
+
+while of_course():
+    this()
+else:
+    ...
+# this comment belongs to the statement coming after the else
+
+
+### No errors
+
+while this_second_comment:
+    belongs()  # to
+# `else`
+else:
+    pass
+
+
+while and_so:
+    does()
+# this
+else:
+    ...
+
+
+while of_course():
+    this()
+else:
+    ...  # too
+
+while of_course():
+    this()
+else:
+    ...
+    # this comment belongs to the else
+

crates/ruff_linter/src/checkers/ast/analyze/statement.rs

@@ -1240,6 +1240,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             if checker.enabled(Rule::IfKeyInDictDel) {
                 ruff::rules::if_key_in_dict_del(checker, if_);
             }
+            if checker.enabled(Rule::NeedlessElse) {
+                ruff::rules::needless_else(checker, if_.into());
+            }
         }
         Stmt::Assert(
             assert_stmt @ ast::StmtAssert {
@@ -1349,6 +1352,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             if checker.enabled(Rule::AsyncBusyWait) {
                 flake8_async::rules::async_busy_wait(checker, while_stmt);
             }
+            if checker.enabled(Rule::NeedlessElse) {
+                ruff::rules::needless_else(checker, while_stmt.into());
+            }
         }
         Stmt::For(
             for_stmt @ ast::StmtFor {
@@ -1438,14 +1444,19 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
                     refurb::rules::for_loop_writes(checker, for_stmt);
                 }
             }
+            if checker.enabled(Rule::NeedlessElse) {
+                ruff::rules::needless_else(checker, for_stmt.into());
             }
-        Stmt::Try(ast::StmtTry {
+        }
+        Stmt::Try(
+            try_stmt @ ast::StmtTry {
                 body,
                 handlers,
                 orelse,
                 finalbody,
                 ..
-        }) => {
+            },
+        ) => {
             if checker.enabled(Rule::TooManyNestedBlocks) {
                 pylint::rules::too_many_nested_blocks(checker, stmt);
             }
@@ -1512,6 +1523,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             if checker.enabled(Rule::ErrorInsteadOfException) {
                 tryceratops::rules::error_instead_of_exception(checker, handlers);
             }
+            if checker.enabled(Rule::NeedlessElse) {
+                ruff::rules::needless_else(checker, try_stmt.into());
+            }
         }
         Stmt::Assign(assign @ ast::StmtAssign { targets, value, .. }) => {
             if checker.enabled(Rule::SelfOrClsAssignment) {

crates/ruff_linter/src/codes.rs

@@ -997,6 +997,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Ruff, "041") => (RuleGroup::Preview, rules::ruff::rules::UnnecessaryNestedLiteral),
         (Ruff, "043") => (RuleGroup::Preview, rules::ruff::rules::PytestRaisesAmbiguousPattern),
         (Ruff, "046") => (RuleGroup::Preview, rules::ruff::rules::UnnecessaryCastToInt),
+        (Ruff, "047") => (RuleGroup::Preview, rules::ruff::rules::NeedlessElse),
         (Ruff, "048") => (RuleGroup::Preview, rules::ruff::rules::MapIntVersionParsing),
         (Ruff, "049") => (RuleGroup::Preview, rules::ruff::rules::DataclassEnum),
         (Ruff, "051") => (RuleGroup::Preview, rules::ruff::rules::IfKeyInDictDel),

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

@@ -79,6 +79,10 @@ mod tests {
     #[test_case(Rule::InvalidAssertMessageLiteralArgument, Path::new("RUF040.py"))]
     #[test_case(Rule::UnnecessaryNestedLiteral, Path::new("RUF041.py"))]
     #[test_case(Rule::UnnecessaryNestedLiteral, Path::new("RUF041.pyi"))]
+    #[test_case(Rule::NeedlessElse, Path::new("RUF047_if.py"))]
+    #[test_case(Rule::NeedlessElse, Path::new("RUF047_for.py"))]
+    #[test_case(Rule::NeedlessElse, Path::new("RUF047_while.py"))]
+    #[test_case(Rule::NeedlessElse, Path::new("RUF047_try.py"))]
     #[test_case(Rule::IfKeyInDictDel, Path::new("RUF051.py"))]
     #[test_case(Rule::UsedDummyVariable, Path::new("RUF052.py"))]
     #[test_case(Rule::FalsyDictGetFallback, Path::new("RUF056.py"))]

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

@@ -21,6 +21,7 @@ pub(crate) use missing_fstring_syntax::*;
 pub(crate) use mutable_class_default::*;
 pub(crate) use mutable_dataclass_default::*;
 pub(crate) use mutable_fromkeys_value::*;
+pub(crate) use needless_else::*;
 pub(crate) use never_union::*;
 pub(crate) use none_not_at_end_of_union::*;
 pub(crate) use parenthesize_chained_operators::*;
@@ -75,6 +76,7 @@ mod missing_fstring_syntax;
 mod mutable_class_default;
 mod mutable_dataclass_default;
 mod mutable_fromkeys_value;
+mod needless_else;
 mod never_union;
 mod none_not_at_end_of_union;
 mod parenthesize_chained_operators;

crates/ruff_linter/src/rules/ruff/rules/needless_else.rs

@@ -0,0 +1,304 @@
+use std::cmp::Ordering;
+
+use ruff_diagnostics::{AlwaysFixableViolation, Diagnostic, Edit, Fix};
+use ruff_macros::{derive_message_formats, ViolationMetadata};
+use ruff_python_ast::helpers::comment_indentation_after;
+use ruff_python_ast::whitespace::indentation;
+use ruff_python_ast::{Stmt, StmtExpr, StmtFor, StmtIf, StmtTry, StmtWhile};
+use ruff_python_parser::{TokenKind, Tokens};
+use ruff_source_file::LineRanges;
+use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};
+
+use crate::checkers::ast::Checker;
+
+/// ## What it does
+/// Checks for `else` clauses that only contains `pass` and `...` statements.
+///
+/// ## Why is this bad?
+/// Such an else clause does nothing and can be removed.
+///
+/// ## Example
+/// ```python
+/// if foo:
+///     bar()
+/// else:
+///     pass
+/// ```
+///
+/// Use instead:
+/// ```python
+/// if foo:
+///     bar()
+/// ```
+#[derive(ViolationMetadata)]
+pub(crate) struct NeedlessElse;
+
+impl AlwaysFixableViolation for NeedlessElse {
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        "Empty `else` clause".to_string()
+    }
+
+    fn fix_title(&self) -> String {
+        "Remove the `else` clause".to_string()
+    }
+}
+
+/// RUF047
+pub(crate) fn needless_else(checker: &mut Checker, stmt: AnyNodeWithOrElse) {
+    let source = checker.source();
+    let tokens = checker.tokens();
+
+    let else_body = stmt.else_body();
+
+    if !body_is_no_op(else_body) {
+        return;
+    }
+
+    let Some(else_range) = stmt.else_range(tokens) else {
+        return;
+    };
+
+    if else_contains_comments(stmt, else_range, checker) {
+        return;
+    }
+
+    let else_line_start = source.line_start(else_range.start());
+    let else_full_end = source.full_line_end(else_range.end());
+    let remove_range = TextRange::new(else_line_start, else_full_end);
+
+    let edit = Edit::range_deletion(remove_range);
+    let fix = Fix::safe_edit(edit);
+
+    let diagnostic = Diagnostic::new(NeedlessElse, else_range);
+
+    checker.diagnostics.push(diagnostic.with_fix(fix));
+}
+
+/// Whether `body` contains only one `pass` or `...` statement.
+fn body_is_no_op(body: &[Stmt]) -> bool {
+    match body {
+        [Stmt::Pass(_)] => true,
+        [Stmt::Expr(StmtExpr { value, .. })] => value.is_ellipsis_literal_expr(),
+        _ => false,
+    }
+}
+
+fn else_contains_comments(
+    stmt: AnyNodeWithOrElse,
+    else_range: TextRange,
+    checker: &Checker,
+) -> bool {
+    let else_full_end = checker.source().full_line_end(else_range.end());
+    let commentable_range = TextRange::new(else_range.start(), else_full_end);
+
+    // A comment after the `else` keyword or after the dummy statement.
+    //
+    // ```python
+    // if ...:
+    //  ...
+    // else: # comment
+    //  pass # comment
+    // ```
+    if checker.comment_ranges().intersects(commentable_range) {
+        return true;
+    }
+
+    let Some(preceding_stmt) = stmt.body_before_else().last() else {
+        return false;
+    };
+
+    let Some(else_last_stmt) = stmt.else_body().last() else {
+        return false;
+    };
+
+    else_branch_has_preceding_comment(preceding_stmt, else_range, checker)
+        || else_branch_has_trailing_comment(else_last_stmt, else_full_end, checker)
+}
+
+/// Returns `true` if the `else` clause header has a leading own-line comment.
+///
+/// ```python
+/// if ...:
+///     ...
+/// # some comment
+/// else:
+///     pass
+/// ```
+fn else_branch_has_preceding_comment(
+    preceding_stmt: &Stmt,
+    else_range: TextRange,
+    checker: &Checker,
+) -> bool {
+    let (tokens, source) = (checker.tokens(), checker.source());
+
+    let before_else_full_end = source.full_line_end(preceding_stmt.end());
+
+    let preceding_indentation = indentation(source, &preceding_stmt)
+        .unwrap_or_default()
+        .text_len();
+
+    for token in tokens.in_range(TextRange::new(before_else_full_end, else_range.start())) {
+        if token.kind() != TokenKind::Comment {
+            continue;
+        }
+
+        let comment_indentation =
+            comment_indentation_after(preceding_stmt.into(), token.range(), source);
+
+        match comment_indentation.cmp(&preceding_indentation) {
+            // Comment belongs to preceding statement.
+            Ordering::Greater | Ordering::Equal => continue,
+            Ordering::Less => return true,
+        }
+    }
+
+    false
+}
+
+/// Returns `true` if the `else` branch has a trailing own line comment:
+///
+/// ```python
+/// if ...:
+///     ...
+/// else:
+///     pass
+///     # some comment
+/// ```
+fn else_branch_has_trailing_comment(
+    last_else_stmt: &Stmt,
+    else_full_end: TextSize,
+    checker: &Checker,
+) -> bool {
+    let (tokens, source) = (checker.tokens(), checker.source());
+
+    let preceding_indentation = indentation(source, &last_else_stmt)
+        .unwrap_or_default()
+        .text_len();
+
+    for token in tokens.after(else_full_end) {
+        match token.kind() {
+            TokenKind::Comment => {
+                let comment_indentation =
+                    comment_indentation_after(last_else_stmt.into(), token.range(), source);
+
+                match comment_indentation.cmp(&preceding_indentation) {
+                    Ordering::Greater | Ordering::Equal => return true,
+                    Ordering::Less => break,
+                }
+            }
+
+            TokenKind::NonLogicalNewline
+            | TokenKind::Newline
+            | TokenKind::Indent
+            | TokenKind::Dedent => {}
+
+            _ => break,
+        }
+    }
+
+    false
+}
+
+#[derive(Copy, Clone, Debug)]
+pub(crate) enum AnyNodeWithOrElse<'a> {
+    While(&'a StmtWhile),
+    For(&'a StmtFor),
+    Try(&'a StmtTry),
+    If(&'a StmtIf),
+}
+
+impl<'a> AnyNodeWithOrElse<'a> {
+    /// Returns the range from the `else` keyword to the last statement in its block.
+    fn else_range(self, tokens: &Tokens) -> Option<TextRange> {
+        match self {
+            Self::For(_) | Self::While(_) | Self::Try(_) => {
+                let before_else = self.body_before_else();
+
+                let else_body = self.else_body();
+                let end = else_body.last()?.end();
+
+                let start = tokens
+                    .in_range(TextRange::new(before_else.last()?.end(), end))
+                    .iter()
+                    .find(|token| token.kind() == TokenKind::Else)?
+                    .start();
+
+                Some(TextRange::new(start, end))
+            }
+
+            Self::If(StmtIf {
+                elif_else_clauses, ..
+            }) => elif_else_clauses
+                .last()
+                .filter(|clause| clause.test.is_none())
+                .map(Ranged::range),
+        }
+    }
+
+    /// Returns the suite before the else block.
+    fn body_before_else(self) -> &'a [Stmt] {
+        match self {
+            Self::Try(StmtTry { body, handlers, .. }) => handlers
+                .last()
+                .and_then(|handler| handler.as_except_handler())
+                .map(|handler| &handler.body)
+                .unwrap_or(body),
+
+            Self::While(StmtWhile { body, .. }) | Self::For(StmtFor { body, .. }) => body,
+
+            Self::If(StmtIf {
+                body,
+                elif_else_clauses,
+                ..
+            }) => elif_else_clauses
+                .iter()
+                .rev()
+                .find(|clause| clause.test.is_some())
+                .map(|clause| &*clause.body)
+                .unwrap_or(body),
+        }
+    }
+
+    /// Returns the `else` suite.
+    /// Defaults to an empty suite if the statement has no `else` block.
+    fn else_body(self) -> &'a [Stmt] {
+        match self {
+            Self::While(StmtWhile { orelse, .. })
+            | Self::For(StmtFor { orelse, .. })
+            | Self::Try(StmtTry { orelse, .. }) => orelse,
+
+            Self::If(StmtIf {
+                elif_else_clauses, ..
+            }) => elif_else_clauses
+                .last()
+                .filter(|clause| clause.test.is_none())
+                .map(|clause| &*clause.body)
+                .unwrap_or_default(),
+        }
+    }
+}
+
+impl<'a> From<&'a StmtFor> for AnyNodeWithOrElse<'a> {
+    fn from(value: &'a StmtFor) -> Self {
+        Self::For(value)
+    }
+}
+
+impl<'a> From<&'a StmtWhile> for AnyNodeWithOrElse<'a> {
+    fn from(value: &'a StmtWhile) -> Self {
+        Self::While(value)
+    }
+}
+
+impl<'a> From<&'a StmtIf> for AnyNodeWithOrElse<'a> {
+    fn from(value: &'a StmtIf) -> Self {
+        Self::If(value)
+    }
+}
+
+impl<'a> From<&'a StmtTry> for AnyNodeWithOrElse<'a> {
+    fn from(value: &'a StmtTry) -> Self {
+        Self::Try(value)
+    }
+}

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF047_RUF047_for.py.snap

@@ -0,0 +1,42 @@
+---
+source: crates/ruff_linter/src/rules/ruff/mod.rs
+---
+RUF047_for.py:6:1: RUF047 [*] Empty `else` clause
+  |
+4 |       loop_body_is_not_checked()
+5 |       break
+6 | / else:
+7 | |     pass
+  | |________^ RUF047
+  |
+  = help: Remove the `else` clause
+
+ℹ Safe fix
+3 3 | for _ in range(0):
+4 4 |     loop_body_is_not_checked()
+5 5 |     break
+6   |-else:
+7   |-    pass
+8 6 | 
+9 7 | 
+10 8 | for this in comment:
+
+RUF047_for.py:12:1: RUF047 [*] Empty `else` clause
+   |
+10 |   for this in comment:
+11 |       belongs_to()  # `for`
+12 | / else:
+13 | |     ...
+   | |_______^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+9  9  | 
+10 10 | for this in comment:
+11 11 |     belongs_to()  # `for`
+12    |-else:
+13    |-    ...
+14 12 | 
+15 13 | 
+16 14 | for of in course():

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF047_RUF047_if.py.snap

@@ -0,0 +1,159 @@
+---
+source: crates/ruff_linter/src/rules/ruff/mod.rs
+---
+RUF047_if.py:5:1: RUF047 [*] Empty `else` clause
+  |
+3 |   if False:
+4 |       condition_is_not_evaluated()
+5 | / else:
+6 | |     pass
+  | |________^ RUF047
+  |
+  = help: Remove the `else` clause
+
+ℹ Safe fix
+2 2 | 
+3 3 | if False:
+4 4 |     condition_is_not_evaluated()
+5   |-else:
+6   |-    pass
+7 5 | 
+8 6 | 
+9 7 | if this_comment():
+
+RUF047_if.py:11:1: RUF047 [*] Empty `else` clause
+   |
+ 9 |   if this_comment():
+10 |       belongs_to()  # `if`
+11 | / else:
+12 | |     ...
+   | |_______^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+8  8  | 
+9  9  | if this_comment():
+10 10 |     belongs_to()  # `if`
+11    |-else:
+12    |-    ...
+13 11 | 
+14 12 | 
+15 13 | if elif_is():
+
+RUF047_if.py:19:1: RUF047 [*] Empty `else` clause
+   |
+17 |   elif the_same():
+18 |       as_if()
+19 | / else:
+20 | |     pass
+   | |________^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+16 16 |     treated()
+17 17 | elif the_same():
+18 18 |     as_if()
+19    |-else:
+20    |-    pass
+21 19 | 
+22 20 | 
+23 21 | if this_second_comment():
+
+RUF047_if.py:26:1: RUF047 [*] Empty `else` clause
+   |
+24 |       belongs()  # to
+25 |         # `if`
+26 | / else:
+27 | |     pass
+   | |________^ RUF047
+28 |
+29 |   if this_second_comment():
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+23 23 | if this_second_comment():
+24 24 |     belongs()  # to
+25 25 |       # `if`
+26    |-else:
+27    |-    pass
+28 26 | 
+29 27 | if this_second_comment():
+30 28 |     belongs()  # to
+
+RUF047_if.py:32:1: RUF047 [*] Empty `else` clause
+   |
+30 |       belongs()  # to
+31 |       # `if`
+32 | / else:
+33 | |     pass
+   | |________^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+29 29 | if this_second_comment():
+30 30 |     belongs()  # to
+31 31 |     # `if`
+32    |-else:
+33    |-    pass
+34 32 | 
+35 33 | 
+36 34 | if of_course():
+
+RUF047_if.py:44:1: RUF047 [*] Empty `else` clause
+   |
+43 | if of_course: this()
+44 | else: ...
+   | ^^^^^^^^^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+41 41 | 
+42 42 | 
+43 43 | if of_course: this()
+44    |-else: ...
+45 44 | 
+46 45 | 
+47 46 | if of_course:
+
+RUF047_if.py:49:1: RUF047 [*] Empty `else` clause
+   |
+47 | if of_course:
+48 |     this() # comment
+49 | else: ...
+   | ^^^^^^^^^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+46 46 | 
+47 47 | if of_course:
+48 48 |     this() # comment
+49    |-else: ...
+50 49 | 
+51 50 | 
+52 51 | def nested():
+
+RUF047_if.py:55:5: RUF047 [*] Empty `else` clause
+   |
+53 |       if a:
+54 |           b()
+55 | /     else:
+56 | |         ...
+   | |___________^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+52 52 | def nested():
+53 53 |     if a:
+54 54 |         b()
+55    |-    else:
+56    |-        ...
+57 55 | 
+58 56 | 
+59 57 | ### No errors

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF047_RUF047_try.py.snap

@@ -0,0 +1,42 @@
+---
+source: crates/ruff_linter/src/rules/ruff/mod.rs
+---
+RUF047_try.py:7:1: RUF047 [*] Empty `else` clause
+  |
+5 |   except:
+6 |       pass
+7 | / else:
+8 | |     pass
+  | |________^ RUF047
+  |
+  = help: Remove the `else` clause
+
+ℹ Safe fix
+4 4 |     raise try_body_is_not_checked()
+5 5 | except:
+6 6 |     pass
+7   |-else:
+8   |-    pass
+9 7 | 
+10 8 | 
+11 9 | try:
+
+RUF047_try.py:17:1: RUF047 [*] Empty `else` clause
+   |
+15 |   except:
+16 |       to()  # `except`
+17 | / else:
+18 | |     ...
+   | |_______^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+14 14 |     belongs()
+15 15 | except:
+16 16 |     to()  # `except`
+17    |-else:
+18    |-    ...
+19 17 | 
+20 18 | 
+21 19 | try:

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF047_RUF047_while.py.snap

@@ -0,0 +1,42 @@
+---
+source: crates/ruff_linter/src/rules/ruff/mod.rs
+---
+RUF047_while.py:6:1: RUF047 [*] Empty `else` clause
+  |
+4 |       loop_body_is_not_checked()
+5 |       break
+6 | / else:
+7 | |     pass
+  | |________^ RUF047
+  |
+  = help: Remove the `else` clause
+
+ℹ Safe fix
+3 3 | while True:
+4 4 |     loop_body_is_not_checked()
+5 5 |     break
+6   |-else:
+7   |-    pass
+8 6 | 
+9 7 | 
+10 8 | while this_comment:
+
+RUF047_while.py:12:1: RUF047 [*] Empty `else` clause
+   |
+10 |   while this_comment:
+11 |       belongs_to()  # `for`
+12 | / else:
+13 | |     ...
+   | |_______^ RUF047
+   |
+   = help: Remove the `else` clause
+
+ℹ Safe fix
+9  9  | 
+10 10 | while this_comment:
+11 11 |     belongs_to()  # `for`
+12    |-else:
+13    |-    ...
+14 12 | 
+15 13 | 
+16 14 | while of_course():

ruff.schema.json

@@ -3921,6 +3921,7 @@
         "RUF041",
         "RUF043",
         "RUF046",
+        "RUF047",
         "RUF048",
         "RUF049",
         "RUF05",