From f3d3fa750c0ecf8f209b74741910dc0632fd3009 Mon Sep 17 00:00:00 2001
From: Charlie Marsh <charlie.r.marsh@gmail.com>
Date: Wed, 22 May 2024 00:11:18 -0400
Subject: [PATCH] Ignore __slots__ with dynamic values

---
 .../fixtures/pylint/non_slot_assignment.py    | 13 +++++++
 .../rules/pylint/rules/non_slot_assignment.rs | 34 +++++++++++++++----
 2 files changed, 41 insertions(+), 6 deletions(-)

diff --git a/crates/ruff_linter/resources/test/fixtures/pylint/non_slot_assignment.py b/crates/ruff_linter/resources/test/fixtures/pylint/non_slot_assignment.py
index 0c443e773cad9..504374c27001b 100644
--- a/crates/ruff_linter/resources/test/fixtures/pylint/non_slot_assignment.py
+++ b/crates/ruff_linter/resources/test/fixtures/pylint/non_slot_assignment.py
@@ -82,3 +82,16 @@ def qux(self):
     @qux.setter
     def qux(self, value):
         self.bar = value / 2
+
+
+class StudentG:
+    names = ("surname",)
+    __slots__ = (*names, "a")
+
+    def __init__(self, name, surname):
+        self.name = name
+        self.surname = surname  # [assigning-non-slot]
+        self.setup()
+
+    def setup(self):
+        pass
diff --git a/crates/ruff_linter/src/rules/pylint/rules/non_slot_assignment.rs b/crates/ruff_linter/src/rules/pylint/rules/non_slot_assignment.rs
index 08260ed04c18a..3e2d8a7bc9e52 100644
--- a/crates/ruff_linter/src/rules/pylint/rules/non_slot_assignment.rs
+++ b/crates/ruff_linter/src/rules/pylint/rules/non_slot_assignment.rs
@@ -98,6 +98,8 @@ impl Ranged for AttributeAssignment<'_> {
 }
 
 /// Return a list of attributes that are assigned to but not included in `__slots__`.
+///
+/// If the `__slots__` attribute cannot be statically determined, returns an empty vector.
 fn is_attributes_not_in_slots(body: &[Stmt]) -> Vec<AttributeAssignment> {
     // First, collect all the attributes that are assigned to `__slots__`.
     let mut slots = FxHashSet::default();
@@ -110,7 +112,13 @@ fn is_attributes_not_in_slots(body: &[Stmt]) -> Vec<AttributeAssignment> {
                 };
 
                 if id == "__slots__" {
-                    slots.extend(slots_attributes(value));
+                    for attribute in slots_attributes(value) {
+                        if let Some(attribute) = attribute {
+                            slots.insert(attribute);
+                        } else {
+                            return vec![];
+                        }
+                    }
                 }
             }
 
@@ -125,7 +133,13 @@ fn is_attributes_not_in_slots(body: &[Stmt]) -> Vec<AttributeAssignment> {
                 };
 
                 if id == "__slots__" {
-                    slots.extend(slots_attributes(value));
+                    for attribute in slots_attributes(value) {
+                        if let Some(attribute) = attribute {
+                            slots.insert(attribute);
+                        } else {
+                            return vec![];
+                        }
+                    }
                 }
             }
 
@@ -136,7 +150,13 @@ fn is_attributes_not_in_slots(body: &[Stmt]) -> Vec<AttributeAssignment> {
                 };
 
                 if id == "__slots__" {
-                    slots.extend(slots_attributes(value));
+                    for attribute in slots_attributes(value) {
+                        if let Some(attribute) = attribute {
+                            slots.insert(attribute);
+                        } else {
+                            return vec![];
+                        }
+                    }
                 }
             }
             _ => {}
@@ -237,12 +257,14 @@ fn is_attributes_not_in_slots(body: &[Stmt]) -> Vec<AttributeAssignment> {
 }
 
 /// Return an iterator over the attributes enumerated in the given `__slots__` value.
-fn slots_attributes(expr: &Expr) -> impl Iterator<Item = &str> {
+///
+/// If an attribute can't be statically determined, it will be `None`.
+fn slots_attributes(expr: &Expr) -> impl Iterator<Item = Option<&str>> {
     // Ex) `__slots__ = ("name",)`
     let elts_iter = match expr {
         Expr::Tuple(ast::ExprTuple { elts, .. })
         | Expr::List(ast::ExprList { elts, .. })
-        | Expr::Set(ast::ExprSet { elts, .. }) => Some(elts.iter().filter_map(|elt| match elt {
+        | Expr::Set(ast::ExprSet { elts, .. }) => Some(elts.iter().map(|elt| match elt {
             Expr::StringLiteral(ast::ExprStringLiteral { value, .. }) => Some(value.to_str()),
             _ => None,
         })),
@@ -251,7 +273,7 @@ fn slots_attributes(expr: &Expr) -> impl Iterator<Item = &str> {
 
     // Ex) `__slots__ = {"name": ...}`
     let keys_iter = match expr {
-        Expr::Dict(dict) => Some(dict.iter_keys().filter_map(|key| match key {
+        Expr::Dict(dict) => Some(dict.iter_keys().map(|key| match key {
             Some(Expr::StringLiteral(ast::ExprStringLiteral { value, .. })) => Some(value.to_str()),
             _ => None,
         })),