Autofix EM101, EM102, EM103 if possible (#4123)

crates/ruff/resources/test/fixtures/flake8_errmsg/EM.py

@@ -21,3 +21,36 @@ def f_c():
 def f_ok():
     msg = "hello"
     raise RuntimeError(msg)
+
+
+def f_unfixable():
+    msg = "hello"
+    raise RuntimeError("This is an example exception")
+
+
+def f_msg_in_nested_scope():
+    def nested():
+        msg = "hello"
+
+    raise RuntimeError("This is an example exception")
+
+
+def f_msg_in_parent_scope():
+    msg = "hello"
+
+    def nested():
+        raise RuntimeError("This is an example exception")
+
+
+def f_fix_indentation_check(foo):
+    if foo:
+        raise RuntimeError("This is an example exception")
+    else:
+        if foo == "foo":
+            raise RuntimeError(f"This is an exception: {foo}")
+    raise RuntimeError("This is an exception: {}".format(foo))
+
+
+# Report these, but don't fix them
+if foo: raise RuntimeError("This is an example exception")
+if foo: x = 1; raise RuntimeError("This is an example exception")

crates/ruff/src/checkers/ast/mod.rs

@@ -1512,7 +1512,7 @@ where
                     Rule::DotFormatInException,
                 ]) {
                     if let Some(exc) = exc {
-                        flake8_errmsg::rules::string_in_exception(self, exc);
+                        flake8_errmsg::rules::string_in_exception(self, stmt, exc);
                     }
                 }
                 if self.settings.rules.enabled(Rule::OSErrorAlias) {

crates/ruff/src/rules/flake8_errmsg/rules.rs

@@ -1,10 +1,13 @@
-use rustpython_parser::ast::{Constant, Expr, ExprKind};
+use rustpython_parser::ast::{Constant, Expr, ExprContext, ExprKind, Stmt, StmtKind};
 
-use ruff_diagnostics::{Diagnostic, Violation};
+use ruff_diagnostics::{AutofixKind, Diagnostic, Edit, Fix, Violation};
 use ruff_macros::{derive_message_formats, violation};
+use ruff_python_ast::helpers::{create_expr, create_stmt, unparse_stmt};
+use ruff_python_ast::source_code::Stylist;
+use ruff_python_ast::whitespace;
 
 use crate::checkers::ast::Checker;
-use crate::registry::Rule;
+use crate::registry::{AsRule, Rule};
 
 /// ## What it does
 /// Checks for the use of string literals in exception constructors.
@@ -44,13 +47,22 @@ use crate::registry::Rule;
 /// RuntimeError: 'Some value' is incorrect
 /// ```
 #[violation]
-pub struct RawStringInException;
+pub struct RawStringInException {
+    pub fixable: bool,
+}
 
 impl Violation for RawStringInException {
+    const AUTOFIX: AutofixKind = AutofixKind::Sometimes;
+
     #[derive_message_formats]
     fn message(&self) -> String {
         format!("Exception must not use a string literal, assign to variable first")
     }
+
+    fn autofix_title_formatter(&self) -> Option<fn(&Self) -> String> {
+        self.fixable
+            .then_some(|_| format!("Assign to variable; remove string literal"))
+    }
 }
 
 /// ## What it does
@@ -92,13 +104,22 @@ impl Violation for RawStringInException {
 /// RuntimeError: 'Some value' is incorrect
 /// ```
 #[violation]
-pub struct FStringInException;
+pub struct FStringInException {
+    pub fixable: bool,
+}
 
 impl Violation for FStringInException {
+    const AUTOFIX: AutofixKind = AutofixKind::Sometimes;
+
     #[derive_message_formats]
     fn message(&self) -> String {
         format!("Exception must not use an f-string literal, assign to variable first")
     }
+
+    fn autofix_title_formatter(&self) -> Option<fn(&Self) -> String> {
+        self.fixable
+            .then_some(|_| format!("Assign to variable; remove f-string literal"))
+    }
 }
 
 /// ## What it does
@@ -142,17 +163,62 @@ impl Violation for FStringInException {
 /// RuntimeError: 'Some value' is incorrect
 /// ```
 #[violation]
-pub struct DotFormatInException;
+pub struct DotFormatInException {
+    pub fixable: bool,
+}
 
 impl Violation for DotFormatInException {
+    const AUTOFIX: AutofixKind = AutofixKind::Sometimes;
+
     #[derive_message_formats]
     fn message(&self) -> String {
         format!("Exception must not use a `.format()` string directly, assign to variable first")
     }
+
+    fn autofix_title_formatter(&self) -> Option<fn(&Self) -> String> {
+        self.fixable
+            .then_some(|_| format!("Assign to variable; remove `.format()` string"))
+    }
+}
+
+/// Generate the [`Fix`] for EM001, EM002, and EM003 violations.
+///
+/// This assumes that the violation is fixable and that the patch should
+/// be generated. The exception argument should be either a string literal,
+/// an f-string, or a `.format` string.
+///
+/// The fix includes two edits:
+/// 1. Insert the exception argument into a variable assignment before the
+///   `raise` statement. The variable name is `msg`.
+/// 2. Replace the exception argument with the variable name.
+fn generate_fix(stylist: &Stylist, stmt: &Stmt, exc_arg: &Expr, indentation: &str) -> Fix {
+    let assignment = unparse_stmt(
+        &create_stmt(StmtKind::Assign {
+            targets: vec![create_expr(ExprKind::Name {
+                id: String::from("msg"),
+                ctx: ExprContext::Store,
+            })],
+            value: Box::new(exc_arg.clone()),
+            type_comment: None,
+        }),
+        stylist,
+    );
+    Fix::from_iter([
+        Edit::insertion(
+            format!(
+                "{}{}{}",
+                assignment,
+                stylist.line_ending().as_str(),
+                indentation,
+            ),
+            stmt.start(),
+        ),
+        Edit::range_replacement(String::from("msg"), exc_arg.range()),
+    ])
 }
 
 /// EM101, EM102, EM103
-pub fn string_in_exception(checker: &mut Checker, exc: &Expr) {
+pub fn string_in_exception(checker: &mut Checker, stmt: &Stmt, exc: &Expr) {
     if let ExprKind::Call { args, .. } = &exc.node {
         if let Some(first) = args.first() {
             match &first.node {
@@ -163,18 +229,63 @@ pub fn string_in_exception(checker: &mut Checker, exc: &Expr) {
                 } => {
                     if checker.settings.rules.enabled(Rule::RawStringInException) {
                         if string.len() > checker.settings.flake8_errmsg.max_string_length {
-                            checker
+                            let indentation = whitespace::indentation(checker.locator, stmt)
-                                .diagnostics
+                                .and_then(|indentation| {
-                                .push(Diagnostic::new(RawStringInException, first.range()));
+                                    if checker.ctx.find_binding("msg").is_none() {
+                                        Some(indentation)
+                                    } else {
+                                        None
+                                    }
+                                });
+                            let mut diagnostic = Diagnostic::new(
+                                RawStringInException {
+                                    fixable: indentation.is_some(),
+                                },
+                                first.range(),
+                            );
+                            if let Some(indentation) = indentation {
+                                if checker.patch(diagnostic.kind.rule()) {
+                                    diagnostic.set_fix(generate_fix(
+                                        checker.stylist,
+                                        stmt,
+                                        first,
+                                        indentation,
+                                    ));
+                                }
+                            }
+                            checker.diagnostics.push(diagnostic);
                         }
                     }
                 }
                 // Check for f-strings
                 ExprKind::JoinedStr { .. } => {
                     if checker.settings.rules.enabled(Rule::FStringInException) {
-                        checker
+                        let indentation = whitespace::indentation(checker.locator, stmt).and_then(
-                            .diagnostics
+                            |indentation| {
-                            .push(Diagnostic::new(FStringInException, first.range()));
+                                if checker.ctx.find_binding("msg").is_none() {
+                                    Some(indentation)
+                                } else {
+                                    None
+                                }
+                            },
+                        );
+                        let mut diagnostic = Diagnostic::new(
+                            FStringInException {
+                                fixable: indentation.is_some(),
+                            },
+                            first.range(),
+                        );
+                        if let Some(indentation) = indentation {
+                            if checker.patch(diagnostic.kind.rule()) {
+                                diagnostic.set_fix(generate_fix(
+                                    checker.stylist,
+                                    stmt,
+                                    first,
+                                    indentation,
+                                ));
+                            }
+                        }
+                        checker.diagnostics.push(diagnostic);
                     }
                 }
                 // Check for .format() calls
@@ -182,9 +293,31 @@ pub fn string_in_exception(checker: &mut Checker, exc: &Expr) {
                     if checker.settings.rules.enabled(Rule::DotFormatInException) {
                         if let ExprKind::Attribute { value, attr, .. } = &func.node {
                             if attr == "format" && matches!(value.node, ExprKind::Constant { .. }) {
-                                checker
+                                let indentation = whitespace::indentation(checker.locator, stmt)
-                                    .diagnostics
+                                    .and_then(|indentation| {
-                                    .push(Diagnostic::new(DotFormatInException, first.range()));
+                                        if checker.ctx.find_binding("msg").is_none() {
+                                            Some(indentation)
+                                        } else {
+                                            None
+                                        }
+                                    });
+                                let mut diagnostic = Diagnostic::new(
+                                    DotFormatInException {
+                                        fixable: indentation.is_some(),
+                                    },
+                                    first.range(),
+                                );
+                                if let Some(indentation) = indentation {
+                                    if checker.patch(diagnostic.kind.rule()) {
+                                        diagnostic.set_fix(generate_fix(
+                                            checker.stylist,
+                                            stmt,
+                                            first,
+                                            indentation,
+                                        ));
+                                    }
+                                }
+                                checker.diagnostics.push(diagnostic);
                             }
                         }
                     }

crates/ruff/src/rules/flake8_errmsg/snapshots/ruff__rules__flake8_errmsg__tests__custom.snap

@@ -1,26 +1,176 @@
 ---
 source: crates/ruff/src/rules/flake8_errmsg/mod.rs
 ---
-EM.py:5:24: EM101 Exception must not use a string literal, assign to variable first
+EM.py:5:24: EM101 [*] Exception must not use a string literal, assign to variable first
   |
 5 | def f_a():
 6 |     raise RuntimeError("This is an example exception")
   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
   |
+  = help: Assign to variable; remove string literal
 
-EM.py:14:24: EM102 Exception must not use an f-string literal, assign to variable first
+ℹ Suggested fix
+2 2 | 
+3 3 | 
+4 4 | def f_a():
+5   |-    raise RuntimeError("This is an example exception")
+  5 |+    msg = "This is an example exception"
+  6 |+    raise RuntimeError(msg)
+6 7 | 
+7 8 | 
+8 9 | def f_a_short():
+
+EM.py:14:24: EM102 [*] Exception must not use an f-string literal, assign to variable first
    |
 14 | def f_b():
 15 |     example = "example"
 16 |     raise RuntimeError(f"This is an {example} exception")
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM102
    |
+   = help: Assign to variable; remove f-string literal
 
-EM.py:18:24: EM103 Exception must not use a `.format()` string directly, assign to variable first
+ℹ Suggested fix
+11 11 | 
+12 12 | def f_b():
+13 13 |     example = "example"
+14    |-    raise RuntimeError(f"This is an {example} exception")
+   14 |+    msg = f"This is an {example} exception"
+   15 |+    raise RuntimeError(msg)
+15 16 | 
+16 17 | 
+17 18 | def f_c():
+
+EM.py:18:24: EM103 [*] Exception must not use a `.format()` string directly, assign to variable first
    |
 18 | def f_c():
 19 |     raise RuntimeError("This is an {example} exception".format(example="example"))
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM103
    |
+   = help: Assign to variable; remove `.format()` string
+
+ℹ Suggested fix
+15 15 | 
+16 16 | 
+17 17 | def f_c():
+18    |-    raise RuntimeError("This is an {example} exception".format(example="example"))
+   18 |+    msg = "This is an {example} exception".format(example="example")
+   19 |+    raise RuntimeError(msg)
+19 20 | 
+20 21 | 
+21 22 | def f_ok():
+
+EM.py:28:24: EM101 Exception must not use a string literal, assign to variable first
+   |
+28 | def f_unfixable():
+29 |     msg = "hello"
+30 |     raise RuntimeError("This is an example exception")
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
+
+EM.py:35:24: EM101 [*] Exception must not use a string literal, assign to variable first
+   |
+35 |         msg = "hello"
+36 | 
+37 |     raise RuntimeError("This is an example exception")
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
+   = help: Assign to variable; remove string literal
+
+ℹ Suggested fix
+32 32 |     def nested():
+33 33 |         msg = "hello"
+34 34 | 
+35    |-    raise RuntimeError("This is an example exception")
+   35 |+    msg = "This is an example exception"
+   36 |+    raise RuntimeError(msg)
+36 37 | 
+37 38 | 
+38 39 | def f_msg_in_parent_scope():
+
+EM.py:42:28: EM101 Exception must not use a string literal, assign to variable first
+   |
+42 |     def nested():
+43 |         raise RuntimeError("This is an example exception")
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
+
+EM.py:47:28: EM101 [*] Exception must not use a string literal, assign to variable first
+   |
+47 | def f_fix_indentation_check(foo):
+48 |     if foo:
+49 |         raise RuntimeError("This is an example exception")
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+50 |     else:
+51 |         if foo == "foo":
+   |
+   = help: Assign to variable; remove string literal
+
+ℹ Suggested fix
+44 44 | 
+45 45 | def f_fix_indentation_check(foo):
+46 46 |     if foo:
+47    |-        raise RuntimeError("This is an example exception")
+   47 |+        msg = "This is an example exception"
+   48 |+        raise RuntimeError(msg)
+48 49 |     else:
+49 50 |         if foo == "foo":
+50 51 |             raise RuntimeError(f"This is an exception: {foo}")
+
+EM.py:50:32: EM102 [*] Exception must not use an f-string literal, assign to variable first
+   |
+50 |     else:
+51 |         if foo == "foo":
+52 |             raise RuntimeError(f"This is an exception: {foo}")
+   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM102
+53 |     raise RuntimeError("This is an exception: {}".format(foo))
+   |
+   = help: Assign to variable; remove f-string literal
+
+ℹ Suggested fix
+47 47 |         raise RuntimeError("This is an example exception")
+48 48 |     else:
+49 49 |         if foo == "foo":
+50    |-            raise RuntimeError(f"This is an exception: {foo}")
+   50 |+            msg = f"This is an exception: {foo}"
+   51 |+            raise RuntimeError(msg)
+51 52 |     raise RuntimeError("This is an exception: {}".format(foo))
+52 53 | 
+53 54 | 
+
+EM.py:51:24: EM103 [*] Exception must not use a `.format()` string directly, assign to variable first
+   |
+51 |         if foo == "foo":
+52 |             raise RuntimeError(f"This is an exception: {foo}")
+53 |     raise RuntimeError("This is an exception: {}".format(foo))
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM103
+   |
+   = help: Assign to variable; remove `.format()` string
+
+ℹ Suggested fix
+48 48 |     else:
+49 49 |         if foo == "foo":
+50 50 |             raise RuntimeError(f"This is an exception: {foo}")
+51    |-    raise RuntimeError("This is an exception: {}".format(foo))
+   51 |+    msg = "This is an exception: {}".format(foo)
+   52 |+    raise RuntimeError(msg)
+52 53 | 
+53 54 | 
+54 55 | # Report these, but don't fix them
+
+EM.py:55:28: EM101 Exception must not use a string literal, assign to variable first
+   |
+55 | # Report these, but don't fix them
+56 | if foo: raise RuntimeError("This is an example exception")
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+57 | if foo: x = 1; raise RuntimeError("This is an example exception")
+   |
+
+EM.py:56:35: EM101 Exception must not use a string literal, assign to variable first
+   |
+56 | # Report these, but don't fix them
+57 | if foo: raise RuntimeError("This is an example exception")
+58 | if foo: x = 1; raise RuntimeError("This is an example exception")
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
 
 

crates/ruff/src/rules/flake8_errmsg/snapshots/ruff__rules__flake8_errmsg__tests__defaults.snap

@@ -1,33 +1,195 @@
 ---
 source: crates/ruff/src/rules/flake8_errmsg/mod.rs
 ---
-EM.py:5:24: EM101 Exception must not use a string literal, assign to variable first
+EM.py:5:24: EM101 [*] Exception must not use a string literal, assign to variable first
   |
 5 | def f_a():
 6 |     raise RuntimeError("This is an example exception")
   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
   |
+  = help: Assign to variable; remove string literal
 
-EM.py:9:24: EM101 Exception must not use a string literal, assign to variable first
+ℹ Suggested fix
+2 2 | 
+3 3 | 
+4 4 | def f_a():
+5   |-    raise RuntimeError("This is an example exception")
+  5 |+    msg = "This is an example exception"
+  6 |+    raise RuntimeError(msg)
+6 7 | 
+7 8 | 
+8 9 | def f_a_short():
+
+EM.py:9:24: EM101 [*] Exception must not use a string literal, assign to variable first
    |
  9 | def f_a_short():
 10 |     raise RuntimeError("Error")
    |                        ^^^^^^^ EM101
    |
+   = help: Assign to variable; remove string literal
 
-EM.py:14:24: EM102 Exception must not use an f-string literal, assign to variable first
+ℹ Suggested fix
+6  6  | 
+7  7  | 
+8  8  | def f_a_short():
+9     |-    raise RuntimeError("Error")
+   9  |+    msg = "Error"
+   10 |+    raise RuntimeError(msg)
+10 11 | 
+11 12 | 
+12 13 | def f_b():
+
+EM.py:14:24: EM102 [*] Exception must not use an f-string literal, assign to variable first
    |
 14 | def f_b():
 15 |     example = "example"
 16 |     raise RuntimeError(f"This is an {example} exception")
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM102
    |
+   = help: Assign to variable; remove f-string literal
 
-EM.py:18:24: EM103 Exception must not use a `.format()` string directly, assign to variable first
+ℹ Suggested fix
+11 11 | 
+12 12 | def f_b():
+13 13 |     example = "example"
+14    |-    raise RuntimeError(f"This is an {example} exception")
+   14 |+    msg = f"This is an {example} exception"
+   15 |+    raise RuntimeError(msg)
+15 16 | 
+16 17 | 
+17 18 | def f_c():
+
+EM.py:18:24: EM103 [*] Exception must not use a `.format()` string directly, assign to variable first
    |
 18 | def f_c():
 19 |     raise RuntimeError("This is an {example} exception".format(example="example"))
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM103
    |
+   = help: Assign to variable; remove `.format()` string
+
+ℹ Suggested fix
+15 15 | 
+16 16 | 
+17 17 | def f_c():
+18    |-    raise RuntimeError("This is an {example} exception".format(example="example"))
+   18 |+    msg = "This is an {example} exception".format(example="example")
+   19 |+    raise RuntimeError(msg)
+19 20 | 
+20 21 | 
+21 22 | def f_ok():
+
+EM.py:28:24: EM101 Exception must not use a string literal, assign to variable first
+   |
+28 | def f_unfixable():
+29 |     msg = "hello"
+30 |     raise RuntimeError("This is an example exception")
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
+
+EM.py:35:24: EM101 [*] Exception must not use a string literal, assign to variable first
+   |
+35 |         msg = "hello"
+36 | 
+37 |     raise RuntimeError("This is an example exception")
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
+   = help: Assign to variable; remove string literal
+
+ℹ Suggested fix
+32 32 |     def nested():
+33 33 |         msg = "hello"
+34 34 | 
+35    |-    raise RuntimeError("This is an example exception")
+   35 |+    msg = "This is an example exception"
+   36 |+    raise RuntimeError(msg)
+36 37 | 
+37 38 | 
+38 39 | def f_msg_in_parent_scope():
+
+EM.py:42:28: EM101 Exception must not use a string literal, assign to variable first
+   |
+42 |     def nested():
+43 |         raise RuntimeError("This is an example exception")
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |
+
+EM.py:47:28: EM101 [*] Exception must not use a string literal, assign to variable first
+   |
+47 | def f_fix_indentation_check(foo):
+48 |     if foo:
+49 |         raise RuntimeError("This is an example exception")
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+50 |     else:
+51 |         if foo == "foo":
+   |
+   = help: Assign to variable; remove string literal
+
+ℹ Suggested fix
+44 44 | 
+45 45 | def f_fix_indentation_check(foo):
+46 46 |     if foo:
+47    |-        raise RuntimeError("This is an example exception")
+   47 |+        msg = "This is an example exception"
+   48 |+        raise RuntimeError(msg)
+48 49 |     else:
+49 50 |         if foo == "foo":
+50 51 |             raise RuntimeError(f"This is an exception: {foo}")
+
+EM.py:50:32: EM102 [*] Exception must not use an f-string literal, assign to variable first
+   |
+50 |     else:
+51 |         if foo == "foo":
+52 |             raise RuntimeError(f"This is an exception: {foo}")
+   |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM102
+53 |     raise RuntimeError("This is an exception: {}".format(foo))
+   |
+   = help: Assign to variable; remove f-string literal
+
+ℹ Suggested fix
+47 47 |         raise RuntimeError("This is an example exception")
+48 48 |     else:
+49 49 |         if foo == "foo":
+50    |-            raise RuntimeError(f"This is an exception: {foo}")
+   50 |+            msg = f"This is an exception: {foo}"
+   51 |+            raise RuntimeError(msg)
+51 52 |     raise RuntimeError("This is an exception: {}".format(foo))
+52 53 | 
+53 54 | 
+
+EM.py:51:24: EM103 [*] Exception must not use a `.format()` string directly, assign to variable first
+   |
+51 |         if foo == "foo":
+52 |             raise RuntimeError(f"This is an exception: {foo}")
+53 |     raise RuntimeError("This is an exception: {}".format(foo))
+   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM103
+   |
+   = help: Assign to variable; remove `.format()` string
+
+ℹ Suggested fix
+48 48 |     else:
+49 49 |         if foo == "foo":
+50 50 |             raise RuntimeError(f"This is an exception: {foo}")
+51    |-    raise RuntimeError("This is an exception: {}".format(foo))
+   51 |+    msg = "This is an exception: {}".format(foo)
+   52 |+    raise RuntimeError(msg)
+52 53 | 
+53 54 | 
+54 55 | # Report these, but don't fix them
+
+EM.py:55:28: EM101 Exception must not use a string literal, assign to variable first
+   |
+55 | # Report these, but don't fix them
+56 | if foo: raise RuntimeError("This is an example exception")
+   |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+57 | if foo: x = 1; raise RuntimeError("This is an example exception")
+   |
+
+EM.py:56:35: EM101 Exception must not use a string literal, assign to variable first
+   |
+56 | # Report these, but don't fix them
+57 | if foo: raise RuntimeError("This is an example exception")
+58 | if foo: x = 1; raise RuntimeError("This is an example exception")
+   |                                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ EM101
+   |