Update rule docs for preview feature

crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B018.py

@@ -6,8 +6,8 @@ class Foo2:
     """abc"""
 
     a = 2
-    "str"  # Str (no raise)
-    f"{int}"  # JoinedStr (no raise)
+    "str"  # StringLiteral
+    f"{int}"  # FString
     1j  # Number (complex)
     1  # Number (int)
     1.0  # Number (float)
@@ -34,8 +34,8 @@ def foo1():
 def foo2():
     """my docstring"""
     a = 2
-    "str"  # Str (no raise)
-    f"{int}"  # JoinedStr (no raise)
+    "str"  # StringLiteral
+    f"{int}"  # FString
     1j  # Number (complex)
     1  # Number (int)
     1.0  # Number (float)

crates/ruff_linter/resources/test/fixtures/flake8_bugbear/B018_attribute_docstring.py

@@ -0,0 +1,93 @@
+# These test cases not only check for `B018` but also verifies that the semantic model
+# correctly identifies certain strings as attribute docstring. And, by way of not
+# raising the `B018` violation, it can be verified.
+
+a: int
+"a: docstring"
+
+b = 1
+"b: docstring" " continue"
+"b: not a docstring"
+
+c: int = 1
+"c: docstring"
+
+_a: int
+"_a: docstring"
+
+if True:
+    d = 1
+    "d: not a docstring"
+
+(e := 1)
+"e: not a docstring"
+
+f = 0
+f += 1
+"f: not a docstring"
+
+g.h = 1
+"g.h: not a docstring"
+
+(i) = 1
+"i: docstring"
+
+(j): int = 1
+"j: docstring"
+
+(k): int
+"k: docstring"
+
+l = m = 1
+"l m: not a docstring"
+
+n.a = n.b = n.c = 1
+"n.*: not a docstring"
+
+(o, p) = (1, 2)
+"o p: not a docstring"
+
+[q, r] = [1, 2]
+"q r: not a docstring"
+
+*s = 1
+"s: not a docstring"
+
+
+class Foo:
+    a = 1
+    "Foo.a: docstring"
+
+    b: int
+    "Foo.b: docstring"
+    "Foo.b: not a docstring"
+
+    c: int = 1
+    "Foo.c: docstring"
+
+    def __init__(self) -> None:
+        # This is actually a docstring but we currently don't detect it.
+        self.x = 1
+        "self.x: not a docstring"
+
+        t = 2
+        "t: not a docstring"
+
+    def random(self):
+        self.y = 2
+        "self.y: not a docstring"
+
+        u = 2
+        "u: not a docstring"
+
+    def add(self, y: int):
+        self.x += y
+
+
+def function():
+    v = 2
+    "v: not a docstring"
+
+
+function.a = 1
+"function.a: not a docstring"

crates/ruff_linter/src/rules/flake8_bugbear/mod.rs

@@ -13,6 +13,7 @@ mod tests {
     use crate::assert_messages;
     use crate::registry::Rule;
 
+    use crate::settings::types::PreviewMode;
     use crate::settings::LinterSettings;
     use crate::test::test_path;
 
@@ -62,6 +63,7 @@ mod tests {
     #[test_case(Rule::UselessContextlibSuppress, Path::new("B022.py"))]
     #[test_case(Rule::UselessExpression, Path::new("B018.ipynb"))]
     #[test_case(Rule::UselessExpression, Path::new("B018.py"))]
+    #[test_case(Rule::UselessExpression, Path::new("B018_attribute_docstring.py"))]
     #[test_case(Rule::LoopIteratorMutation, Path::new("B909.py"))]
     fn rules(rule_code: Rule, path: &Path) -> Result<()> {
         let snapshot = format!("{}_{}", rule_code.noqa_code(), path.to_string_lossy());
@@ -73,6 +75,26 @@ mod tests {
         Ok(())
     }
 
+    #[test_case(Rule::UselessExpression, Path::new("B018.ipynb"))]
+    #[test_case(Rule::UselessExpression, Path::new("B018.py"))]
+    #[test_case(Rule::UselessExpression, Path::new("B018_attribute_docstring.py"))]
+    fn preview_rules(rule_code: Rule, path: &Path) -> Result<()> {
+        let snapshot = format!(
+            "preview__{}_{}",
+            rule_code.noqa_code(),
+            path.to_string_lossy()
+        );
+        let diagnostics = test_path(
+            Path::new("flake8_bugbear").join(path).as_path(),
+            &LinterSettings {
+                preview: PreviewMode::Enabled,
+                ..LinterSettings::for_rule(rule_code)
+            },
+        )?;
+        assert_messages!(snapshot, diagnostics);
+        Ok(())
+    }
+
     #[test]
     fn zip_without_explicit_strict() -> Result<()> {
         let snapshot = "B905.py";

crates/ruff_linter/src/rules/flake8_bugbear/rules/useless_expression.rs

@@ -16,6 +16,9 @@ use super::super::helpers::at_last_top_level_expression_in_cell;
 /// by mistake. Assign a useless expression to a variable, or remove it
 /// entirely.
 ///
+/// In [preview mode], this rule will also flag string literals and f-strings that
+/// are not used as a docstring or an attribute docstring.
+///
 /// ## Example
 /// ```python
 /// 1 + 1
@@ -45,6 +48,8 @@ use super::super::helpers::at_last_top_level_expression_in_cell;
 /// with errors.ExceptionRaisedContext():
 ///     _ = obj.attribute
 /// ```
+///
+/// [preview]: https://docs.astral.sh/ruff/preview/
 #[violation]
 pub struct UselessExpression {
     kind: Kind,
@@ -69,15 +74,16 @@ impl Violation for UselessExpression {
 /// B018
 pub(crate) fn useless_expression(checker: &mut Checker, value: &Expr) {
     // Ignore comparisons, as they're handled by `useless_comparison`.
-    if value.is_compare_expr() {
+    if matches!(value, Expr::Compare(_) | Expr::EllipsisLiteral(_)) {
         return;
     }
 
-    // Ignore strings, to avoid false positives with docstrings.
-    if matches!(
-        value,
-        Expr::FString(_) | Expr::StringLiteral(_) | Expr::EllipsisLiteral(_)
-    ) {
+    if checker.settings.preview.is_enabled() {
+        if checker.semantic().in_pep_257_docstring() || checker.semantic().in_attribute_docstring()
+        {
+            return;
+        }
+    } else if matches!(value, Expr::StringLiteral(_) | Expr::FString(_)) {
         return;
     }
 

crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B018_B018.py.snap

@@ -3,8 +3,8 @@ source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs
 ---
 B018.py:11:5: B018 Found useless expression. Either assign it to a variable or remove it.
    |
- 9 |     "str"  # Str (no raise)
-10 |     f"{int}"  # JoinedStr (no raise)
+ 9 |     "str"  # StringLiteral
+10 |     f"{int}"  # FString
 11 |     1j  # Number (complex)
    |     ^^ B018
 12 |     1  # Number (int)
@@ -13,7 +13,7 @@ B018.py:11:5: B018 Found useless expression. Either assign it to a variable or r
 
 B018.py:12:5: B018 Found useless expression. Either assign it to a variable or remove it.
    |
-10 |     f"{int}"  # JoinedStr (no raise)
+10 |     f"{int}"  # FString
 11 |     1j  # Number (complex)
 12 |     1  # Number (int)
    |     ^ B018
@@ -117,8 +117,8 @@ B018.py:27:5: B018 Found useless expression. Either assign it to a variable or r
 
 B018.py:39:5: B018 Found useless expression. Either assign it to a variable or remove it.
    |
-37 |     "str"  # Str (no raise)
-38 |     f"{int}"  # JoinedStr (no raise)
+37 |     "str"  # StringLiteral
+38 |     f"{int}"  # FString
 39 |     1j  # Number (complex)
    |     ^^ B018
 40 |     1  # Number (int)
@@ -127,7 +127,7 @@ B018.py:39:5: B018 Found useless expression. Either assign it to a variable or r
 
 B018.py:40:5: B018 Found useless expression. Either assign it to a variable or remove it.
    |
-38 |     f"{int}"  # JoinedStr (no raise)
+38 |     f"{int}"  # FString
 39 |     1j  # Number (complex)
 40 |     1  # Number (int)
    |     ^ B018
@@ -254,5 +254,3 @@ B018.py:65:5: B018 Found useless expression. Either assign it to a variable or r
 65 |     "foo" + "bar"  # BinOp (raise)
    |     ^^^^^^^^^^^^^ B018
    |
-
-

crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__B018_B018_attribute_docstring.py.snap

@@ -0,0 +1,11 @@
+---
+source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs
+---
+B018_attribute_docstring.py:22:2: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+20 |     "d: not a docstring"
+21 | 
+22 | (e := 1)
+   |  ^^^^^^ B018
+23 | "e: not a docstring"
+   |

crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B018_B018.ipynb.snap

@@ -0,0 +1,32 @@
+---
+source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs
+---
+B018.ipynb:5:1: B018 Found useless expression. Either assign it to a variable or remove it.
+  |
+3 | x
+4 | # Only skip the last expression
+5 | x  # B018
+  | ^ B018
+6 | x
+7 | # Nested expressions isn't relevant
+  |
+
+B018.ipynb:9:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+ 7 | # Nested expressions isn't relevant
+ 8 | if True:
+ 9 |     x
+   |     ^ B018
+10 | # Semicolons shouldn't affect the output
+11 | x;
+   |
+
+B018.ipynb:13:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+11 | x;
+12 | # Semicolons with multiple expressions
+13 | x; x
+   | ^ B018
+14 | # Comments, newlines and whitespace
+15 | x  # comment
+   |

crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B018_B018.py.snap

@@ -0,0 +1,295 @@
+---
+source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs
+---
+B018.py:10:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+ 8 |     a = 2
+ 9 |     "str"  # StringLiteral
+10 |     f"{int}"  # FString
+   |     ^^^^^^^^ B018
+11 |     1j  # Number (complex)
+12 |     1  # Number (int)
+   |
+
+B018.py:11:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+ 9 |     "str"  # StringLiteral
+10 |     f"{int}"  # FString
+11 |     1j  # Number (complex)
+   |     ^^ B018
+12 |     1  # Number (int)
+13 |     1.0  # Number (float)
+   |
+
+B018.py:12:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+10 |     f"{int}"  # FString
+11 |     1j  # Number (complex)
+12 |     1  # Number (int)
+   |     ^ B018
+13 |     1.0  # Number (float)
+14 |     b"foo"  # Binary
+   |
+
+B018.py:13:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+11 |     1j  # Number (complex)
+12 |     1  # Number (int)
+13 |     1.0  # Number (float)
+   |     ^^^ B018
+14 |     b"foo"  # Binary
+15 |     True  # NameConstant (True)
+   |
+
+B018.py:14:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+12 |     1  # Number (int)
+13 |     1.0  # Number (float)
+14 |     b"foo"  # Binary
+   |     ^^^^^^ B018
+15 |     True  # NameConstant (True)
+16 |     False  # NameConstant (False)
+   |
+
+B018.py:15:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+13 |     1.0  # Number (float)
+14 |     b"foo"  # Binary
+15 |     True  # NameConstant (True)
+   |     ^^^^ B018
+16 |     False  # NameConstant (False)
+17 |     None  # NameConstant (None)
+   |
+
+B018.py:16:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+14 |     b"foo"  # Binary
+15 |     True  # NameConstant (True)
+16 |     False  # NameConstant (False)
+   |     ^^^^^ B018
+17 |     None  # NameConstant (None)
+18 |     [1, 2]  # list
+   |
+
+B018.py:17:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+15 |     True  # NameConstant (True)
+16 |     False  # NameConstant (False)
+17 |     None  # NameConstant (None)
+   |     ^^^^ B018
+18 |     [1, 2]  # list
+19 |     {1, 2}  # set
+   |
+
+B018.py:18:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+16 |     False  # NameConstant (False)
+17 |     None  # NameConstant (None)
+18 |     [1, 2]  # list
+   |     ^^^^^^ B018
+19 |     {1, 2}  # set
+20 |     {"foo": "bar"}  # dict
+   |
+
+B018.py:19:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+17 |     None  # NameConstant (None)
+18 |     [1, 2]  # list
+19 |     {1, 2}  # set
+   |     ^^^^^^ B018
+20 |     {"foo": "bar"}  # dict
+   |
+
+B018.py:20:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+18 |     [1, 2]  # list
+19 |     {1, 2}  # set
+20 |     {"foo": "bar"}  # dict
+   |     ^^^^^^^^^^^^^^ B018
+   |
+
+B018.py:24:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+23 | class Foo3:
+24 |     123
+   |     ^^^ B018
+25 |     a = 2
+26 |     "str"
+   |
+
+B018.py:27:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+25 |     a = 2
+26 |     "str"
+27 |     1
+   |     ^ B018
+   |
+
+B018.py:37:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+35 |     """my docstring"""
+36 |     a = 2
+37 |     "str"  # StringLiteral
+   |     ^^^^^ B018
+38 |     f"{int}"  # FString
+39 |     1j  # Number (complex)
+   |
+
+B018.py:38:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+36 |     a = 2
+37 |     "str"  # StringLiteral
+38 |     f"{int}"  # FString
+   |     ^^^^^^^^ B018
+39 |     1j  # Number (complex)
+40 |     1  # Number (int)
+   |
+
+B018.py:39:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+37 |     "str"  # StringLiteral
+38 |     f"{int}"  # FString
+39 |     1j  # Number (complex)
+   |     ^^ B018
+40 |     1  # Number (int)
+41 |     1.0  # Number (float)
+   |
+
+B018.py:40:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+38 |     f"{int}"  # FString
+39 |     1j  # Number (complex)
+40 |     1  # Number (int)
+   |     ^ B018
+41 |     1.0  # Number (float)
+42 |     b"foo"  # Binary
+   |
+
+B018.py:41:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+39 |     1j  # Number (complex)
+40 |     1  # Number (int)
+41 |     1.0  # Number (float)
+   |     ^^^ B018
+42 |     b"foo"  # Binary
+43 |     True  # NameConstant (True)
+   |
+
+B018.py:42:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+40 |     1  # Number (int)
+41 |     1.0  # Number (float)
+42 |     b"foo"  # Binary
+   |     ^^^^^^ B018
+43 |     True  # NameConstant (True)
+44 |     False  # NameConstant (False)
+   |
+
+B018.py:43:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+41 |     1.0  # Number (float)
+42 |     b"foo"  # Binary
+43 |     True  # NameConstant (True)
+   |     ^^^^ B018
+44 |     False  # NameConstant (False)
+45 |     None  # NameConstant (None)
+   |
+
+B018.py:44:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+42 |     b"foo"  # Binary
+43 |     True  # NameConstant (True)
+44 |     False  # NameConstant (False)
+   |     ^^^^^ B018
+45 |     None  # NameConstant (None)
+46 |     [1, 2]  # list
+   |
+
+B018.py:45:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+43 |     True  # NameConstant (True)
+44 |     False  # NameConstant (False)
+45 |     None  # NameConstant (None)
+   |     ^^^^ B018
+46 |     [1, 2]  # list
+47 |     {1, 2}  # set
+   |
+
+B018.py:46:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+44 |     False  # NameConstant (False)
+45 |     None  # NameConstant (None)
+46 |     [1, 2]  # list
+   |     ^^^^^^ B018
+47 |     {1, 2}  # set
+48 |     {"foo": "bar"}  # dict
+   |
+
+B018.py:47:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+45 |     None  # NameConstant (None)
+46 |     [1, 2]  # list
+47 |     {1, 2}  # set
+   |     ^^^^^^ B018
+48 |     {"foo": "bar"}  # dict
+   |
+
+B018.py:48:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+46 |     [1, 2]  # list
+47 |     {1, 2}  # set
+48 |     {"foo": "bar"}  # dict
+   |     ^^^^^^^^^^^^^^ B018
+   |
+
+B018.py:52:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+51 | def foo3():
+52 |     123
+   |     ^^^ B018
+53 |     a = 2
+54 |     "str"
+   |
+
+B018.py:54:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+52 |     123
+53 |     a = 2
+54 |     "str"
+   |     ^^^^^ B018
+55 |     3
+   |
+
+B018.py:55:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+53 |     a = 2
+54 |     "str"
+55 |     3
+   |     ^ B018
+   |
+
+B018.py:63:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+62 | def foo5():
+63 |     foo.bar  # Attribute (raise)
+   |     ^^^^^^^ B018
+64 |     object().__class__  # Attribute (raise)
+65 |     "foo" + "bar"  # BinOp (raise)
+   |
+
+B018.py:64:5: B018 Found useless attribute access. Either assign it to a variable or remove it.
+   |
+62 | def foo5():
+63 |     foo.bar  # Attribute (raise)
+64 |     object().__class__  # Attribute (raise)
+   |     ^^^^^^^^^^^^^^^^^^ B018
+65 |     "foo" + "bar"  # BinOp (raise)
+   |
+
+B018.py:65:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+63 |     foo.bar  # Attribute (raise)
+64 |     object().__class__  # Attribute (raise)
+65 |     "foo" + "bar"  # BinOp (raise)
+   |     ^^^^^^^^^^^^^ B018
+   |

crates/ruff_linter/src/rules/flake8_bugbear/snapshots/ruff_linter__rules__flake8_bugbear__tests__preview__B018_B018_attribute_docstring.py.snap

@@ -0,0 +1,165 @@
+---
+source: crates/ruff_linter/src/rules/flake8_bugbear/mod.rs
+---
+B018_attribute_docstring.py:10:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+ 8 | b = 1
+ 9 | "b: docstring" " continue"
+10 | "b: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^ B018
+11 | 
+12 | c: int = 1
+   |
+
+B018_attribute_docstring.py:20:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+18 | if True:
+19 |     d = 1
+20 |     "d: not a docstring"
+   |     ^^^^^^^^^^^^^^^^^^^^ B018
+21 | 
+22 | (e := 1)
+   |
+
+B018_attribute_docstring.py:22:2: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+20 |     "d: not a docstring"
+21 | 
+22 | (e := 1)
+   |  ^^^^^^ B018
+23 | "e: not a docstring"
+   |
+
+B018_attribute_docstring.py:23:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+22 | (e := 1)
+23 | "e: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^ B018
+24 | 
+25 | f = 0
+   |
+
+B018_attribute_docstring.py:27:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+25 | f = 0
+26 | f += 1
+27 | "f: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^ B018
+28 | 
+29 | g.h = 1
+   |
+
+B018_attribute_docstring.py:30:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+29 | g.h = 1
+30 | "g.h: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^^^ B018
+31 | 
+32 | (i) = 1
+   |
+
+B018_attribute_docstring.py:42:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+41 | l = m = 1
+42 | "l m: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^^^ B018
+43 | 
+44 | n.a = n.b = n.c = 1
+   |
+
+B018_attribute_docstring.py:45:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+44 | n.a = n.b = n.c = 1
+45 | "n.*: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^^^ B018
+46 | 
+47 | (o, p) = (1, 2)
+   |
+
+B018_attribute_docstring.py:48:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+47 | (o, p) = (1, 2)
+48 | "o p: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^^^ B018
+49 | 
+50 | [q, r] = [1, 2]
+   |
+
+B018_attribute_docstring.py:51:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+50 | [q, r] = [1, 2]
+51 | "q r: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^^^ B018
+52 | 
+53 | *s = 1
+   |
+
+B018_attribute_docstring.py:54:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+53 | *s = 1
+54 | "s: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^ B018
+   |
+
+B018_attribute_docstring.py:63:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+61 |     b: int
+62 |     "Foo.b: docstring"
+63 |     "Foo.b: not a docstring"
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^ B018
+64 | 
+65 |     c: int = 1
+   |
+
+B018_attribute_docstring.py:71:9: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+69 |         # This is actually a docstring but we currently don't detect it.
+70 |         self.x = 1
+71 |         "self.x: not a docstring"
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^ B018
+72 | 
+73 |         t = 2
+   |
+
+B018_attribute_docstring.py:74:9: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+73 |         t = 2
+74 |         "t: not a docstring"
+   |         ^^^^^^^^^^^^^^^^^^^^ B018
+75 | 
+76 |     def random(self):
+   |
+
+B018_attribute_docstring.py:78:9: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+76 |     def random(self):
+77 |         self.y = 2
+78 |         "self.y: not a docstring"
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^ B018
+79 | 
+80 |         u = 2
+   |
+
+B018_attribute_docstring.py:81:9: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+80 |         u = 2
+81 |         "u: not a docstring"
+   |         ^^^^^^^^^^^^^^^^^^^^ B018
+82 | 
+83 |     def add(self, y: int):
+   |
+
+B018_attribute_docstring.py:89:5: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+87 | def function():
+88 |     v = 2
+89 |     "v: not a docstring"
+   |     ^^^^^^^^^^^^^^^^^^^^ B018
+   |
+
+B018_attribute_docstring.py:93:1: B018 Found useless expression. Either assign it to a variable or remove it.
+   |
+92 | function.a = 1
+93 | "function.a: not a docstring"
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ B018
+   |