From ce0800fccf7c7f712ff36d98140e7d9946329136 Mon Sep 17 00:00:00 2001
From: yunchi <yunchipang@gmail.com>
Date: Wed, 7 May 2025 11:34:34 -0700
Subject: [PATCH] [`pylint`] add fix safety section (`PLC2801`) (#17825)

parent: #15584
fix was introduced at: #9587
reasoning: #9572
---
 .../pylint/rules/unnecessary_dunder_call.rs   | 28 +++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/crates/ruff_linter/src/rules/pylint/rules/unnecessary_dunder_call.rs b/crates/ruff_linter/src/rules/pylint/rules/unnecessary_dunder_call.rs
index 28163c94fc..6da31dbd85 100644
--- a/crates/ruff_linter/src/rules/pylint/rules/unnecessary_dunder_call.rs
+++ b/crates/ruff_linter/src/rules/pylint/rules/unnecessary_dunder_call.rs
@@ -15,6 +15,34 @@ use ruff_python_ast::PythonVersion;
 /// Dunder names are not meant to be called explicitly and, in most cases, can
 /// be replaced with builtins or operators.
 ///
+/// ## Fix safety
+/// This fix is always unsafe. When replacing dunder method calls with operators
+/// or builtins, the behavior can change in the following ways:
+///
+/// 1. Types may implement only a subset of related dunder methods. Calling a
+///    missing dunder method directly returns `NotImplemented`, but using the
+///    equivalent operator raises a `TypeError`.
+///    ```python
+///    class C: pass
+///    c = C()
+///    c.__gt__(1)  # before fix: NotImplemented
+///    c > 1        # after fix: raises TypeError
+///    ```
+/// 2. Instance-assigned dunder methods are ignored by operators and builtins.
+///    ```python
+///    class C: pass
+///    c = C()
+///    c.__bool__ = lambda: False
+///    c.__bool__() # before fix: False
+///    bool(c)      # after fix: True
+///    ```
+///
+/// 3. Even with built-in types, behavior can differ.
+///    ```python
+///    (1).__gt__(1.0)  # before fix: NotImplemented
+///    1 > 1.0          # after fix: False
+///    ```
+///
 /// ## Example
 /// ```python
 /// three = (3.0).__str__()