Use function_type::classify for yield-in-init (#2742)

README.md

@@ -1360,7 +1360,7 @@ For more, see [Pylint](https://pypi.org/project/pylint/) on PyPI.
 
 | Code | Name | Message | Fix |
 | ---- | ---- | ------- | --- |
-| PLE0100 | yield-in-init | `__init__` method is a generator |  |
+| PLE0100 | [yield-in-init](https://github.com/charliermarsh/ruff/blob/main/docs/rules/yield-in-init.md) | `__init__` method is a generator |  |
 | PLE0117 | nonlocal-without-binding | Nonlocal name `{name}` found without binding |  |
 | PLE0118 | used-prior-global-declaration | Name `{name}` is used prior to global declaration on line {line} |  |
 | PLE0604 | invalid-all-object | Invalid object in `__all__`, must contain only strings |  |

crates/ruff/src/checkers/ast.rs

@@ -3884,6 +3884,14 @@ impl<'a> Checker<'a> {
         &self.scopes[*(self.scope_stack.last().expect("No current scope found"))]
     }
 
+    pub fn current_scope_parent(&self) -> Option<&Scope> {
+        self.scope_stack
+            .iter()
+            .rev()
+            .nth(1)
+            .map(|index| &self.scopes[*index])
+    }
+
     pub fn current_scopes(&self) -> impl Iterator<Item = &Scope> {
         self.scope_stack
             .iter()

crates/ruff/src/rules/pylint/rules/yield_in_init.rs

@@ -1,6 +1,9 @@
-use ruff_macros::{define_violation, derive_message_formats};
 use rustpython_parser::ast::Expr;
 
+use ruff_macros::{define_violation, derive_message_formats};
+
+use crate::ast::function_type;
+use crate::ast::function_type::FunctionType;
 use crate::{
     ast::types::{FunctionDef, Range, ScopeKind},
     checkers::ast::Checker,
@@ -9,6 +12,19 @@ use crate::{
 };
 
 define_violation!(
+    /// ### What it does
+    /// Checks for `__init__.py` methods that turned into generators
+    /// via the presence of `yield` or `yield from` statements.
+    ///
+    /// ### Why is this bad?
+    /// Generators are not allowed in `__init__.py` methods.
+    ///
+    /// ### Example
+    /// ```python
+    /// class Foo:
+    ///     def __init__(self):
+    ///         yield 1
+    /// ```
     pub struct YieldInInit;
 );
 
@@ -21,23 +37,38 @@ impl Violation for YieldInInit {
 
 /// PLE0100
 pub fn yield_in_init(checker: &mut Checker, expr: &Expr) {
-    let parent_scope_is_class: Option<bool> =
-        checker
-            .current_scopes()
-            .nth(1)
-            .and_then(|scope| match scope.kind {
-                ScopeKind::Class(..) => Some(true),
-                _ => None,
-            });
-
-    let current_scope_is_init = match checker.current_scope().kind {
-        ScopeKind::Function(FunctionDef { name, .. }) => Some(name == "__init__"),
-        _ => None,
+    let scope = checker.current_scope();
+    let ScopeKind::Function(FunctionDef {
+        name,
+        decorator_list,
+        ..
+    }) = &scope.kind else {
+        return;
+    };
+
+    if *name != "__init__" {
+        return;
+    }
+
+    let Some(parent) = checker.current_scope_parent() else {
+        return;
     };
 
-    if parent_scope_is_class == Some(true) && current_scope_is_init == Some(true) {
-        checker
-            .diagnostics
-            .push(Diagnostic::new(YieldInInit, Range::from_located(expr)));
+    if !matches!(
+        function_type::classify(
+            checker,
+            parent,
+            name,
+            decorator_list,
+            &checker.settings.pep8_naming.classmethod_decorators,
+            &checker.settings.pep8_naming.staticmethod_decorators,
+        ),
+        FunctionType::Method
+    ) {
+        return;
     }
+
+    checker
+        .diagnostics
+        .push(Diagnostic::new(YieldInInit, Range::from_located(expr)));
 }

docs/rules/yield-in-init.md

@@ -0,0 +1,17 @@
+# yield-in-init (PLE0100)
+
+Derived from the **Pylint** linter.
+
+### What it does
+Checks for `__init__.py` methods that turned into generators
+via the presence of `yield` or `yield from` statements.
+
+### Why is this bad?
+Generators are not allowed in `__init__.py` methods.
+
+### Example
+```python
+class Foo:
+    def __init__(self):
+        yield 1
+```