fix dunder slots definition #4344

pyrefly/lib/alt/answers.rs

@@ -1527,6 +1527,19 @@ impl Answers {
         // the preallocated solutions table represents a complete result set.
         if let Some(index) = &self.index {
             let mut index = index.lock();
+            // Retain export occurrences so unopened reverse dependencies need no AST or answers.
+            for entry in bindings.dunder_all_entries() {
+                if let Some(key) = bindings.dunder_all_binding(&entry.id)
+                    && let Some(IntermediateDefinition::NamedImport(_, module, name, None)) =
+                        key_to_intermediate_definition(bindings, key)
+                {
+                    index
+                        .externally_defined_variable_references
+                        .entry((module, name))
+                        .or_default()
+                        .push(entry.range);
+                }
+            }
             // Index bindings with external definitions.
             for idx in bindings.keys::<Key>() {
                 let key = bindings.idx_to_key(idx);

pyrefly/lib/alt/class/class_metadata.rs

@@ -5,8 +5,6 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-use std::iter;
-
 use dupe::Dupe;
 use dupe::IterDupedExt;
 use itertools::Itertools;
@@ -69,7 +67,6 @@ use crate::binding::base_class::BaseClassGeneric;
 use crate::binding::base_class::BaseClassGenericKind;
 use crate::binding::binding::Binding;
 use crate::binding::binding::ClassFieldDefinition;
-use crate::binding::binding::ExprOrBinding;
 use crate::binding::binding::Key;
 use crate::binding::binding::KeyAnnotation;
 use crate::binding::binding::KeyClassField;
@@ -710,33 +707,10 @@ impl<'ctx, 'answer, Ans: LookupAnswer> AnswersSolver<'ctx, 'answer, Ans> {
             return ExplicitSlots::Absent;
         };
         let binding = self.bindings().get::<KeyClassField>(idx);
-        let ClassFieldDefinition::AssignedInBody { value, .. } = &binding.definition else {
-            return ExplicitSlots::Unknown;
-        };
-        let ExprOrBinding::Expr(expr) = value.as_ref() else {
-            return ExplicitSlots::Unknown;
-        };
-
-        fn name_of(expr: &Expr) -> Option<Name> {
-            match expr {
-                Expr::StringLiteral(s) => Some(Name::new(s.value.to_str())),
-                _ => None,
-            }
-        }
-        let names: Option<SmallSet<Name>> = match expr {
-            Expr::Tuple(t) => t.elts.iter().map(name_of).collect(),
-            Expr::List(l) => l.elts.iter().map(name_of).collect(),
-            Expr::Dict(d) => d
-                .items
-                .iter()
-                .map(|item| item.key.as_ref().and_then(name_of))
-                .collect(),
-            Expr::StringLiteral(s) => Some(iter::once(Name::new(s.value.to_str())).collect()),
-            _ => return ExplicitSlots::Unknown,
-        };
-        let Some(names) = names else {
+        let Some(entries) = binding.explicit_slots() else {
             return ExplicitSlots::Unknown;
         };
+        let names: SmallSet<Name> = entries.into_iter().map(|(name, _)| name).collect();
         // A metaclass other than `type` or `ABCMeta` may remove names from the namespace before it
         // creates the class.
         if cls.module().path().is_interface()

pyrefly/lib/binding/binding.rs

@@ -3727,6 +3727,38 @@ pub struct BindingClassField {
     pub definition: ClassFieldDefinition,
 }
 
+impl BindingClassField {
+    /// Extract literal slot names and their editable content ranges from the checked field.
+    pub fn explicit_slots(&self) -> Option<Vec<(Name, Option<TextRange>)>> {
+        let ClassFieldDefinition::AssignedInBody { value, .. } = &self.definition else {
+            return None;
+        };
+        let ExprOrBinding::Expr(expr) = value.as_ref() else {
+            return None;
+        };
+        let name_of = |expr: &Expr| match expr {
+            Expr::StringLiteral(literal) => Some((
+                Name::new(literal.value.to_str()),
+                literal
+                    .as_single_part_string()
+                    .map(|part| part.content_range()),
+            )),
+            _ => None,
+        };
+        match expr {
+            Expr::Tuple(tuple) => tuple.elts.iter().map(name_of).collect(),
+            Expr::List(list) => list.elts.iter().map(name_of).collect(),
+            Expr::Dict(dict) => dict
+                .items
+                .iter()
+                .map(|item| item.key.as_ref().and_then(name_of))
+                .collect(),
+            Expr::StringLiteral(_) => Some(vec![name_of(expr)?]),
+            _ => None,
+        }
+    }
+}
+
 impl DisplayWith<Bindings> for BindingClassField {
     fn fmt(&self, f: &mut fmt::Formatter<'_>, ctx: &Bindings) -> fmt::Result {
         write!(

pyrefly/lib/binding/bindings.rs

@@ -417,6 +417,13 @@ table! {
     pub struct BindingTable(pub BindingEntry)
 }
 
+/// A literal slot occurrence and the class whose field binding declares it.
+#[derive(Debug)]
+pub struct SlotEntry {
+    pub name: Identifier,
+    pub class_idx: Idx<KeyClass>,
+}
+
 #[derive(Debug)]
 pub struct Bindings {
     module_info: ModuleInfo,
@@ -433,6 +440,9 @@ pub struct Bindings {
     annotated_metadata_ranges: Vec<TextRange>,
     /// Ranges of the types that were read from docstrings, sorted and non-overlapping.
     docstring_type_ranges: Vec<TextRange>,
+    /// Each entry records an `__all__` name and its range without string delimiters.
+    dunder_all_entries: Vec<Identifier>,
+    dunder_slots_entries: Vec<SlotEntry>,
     scope_trace: Option<ScopeTrace>,
     /// Names `del`eted at module scope; retained outside the LSP `scope_trace`.
     module_deletes: SmallSet<Name>,
@@ -694,6 +704,8 @@ impl Bindings {
             annotated_metadata_ranges: Vec::new(),
             docstring_type_ranges: Vec::new(),
             scope_trace: None,
+            dunder_all_entries: Vec::new(),
+            dunder_slots_entries: Vec::new(),
             module_deletes: SmallSet::new(),
             unset_nodes: UnsetNodes::default(),
             global_declarations: SmallSet::new(),
@@ -951,6 +963,26 @@ impl Bindings {
         }
     }
 
+    pub fn dunder_slots_entries(&self) -> &[SlotEntry] {
+        &self.dunder_slots_entries
+    }
+
+    pub fn dunder_slots_entry_at(&self, position: TextSize) -> Option<&SlotEntry> {
+        self.dunder_slots_entries
+            .iter()
+            .find(|entry| entry.name.range.contains_inclusive(position))
+    }
+
+    pub fn dunder_all_entries(&self) -> &[Identifier] {
+        &self.dunder_all_entries
+    }
+
+    /// Return the final local binding for an export, preserving local import aliases.
+    pub fn dunder_all_binding(&self, name: &Name) -> Option<&Key> {
+        let export = self.key_to_idx_hashed_opt(Hashed::new(&KeyExport(name.clone())))?;
+        Some(self.idx_to_key(self.get(export).key_idx()))
+    }
+
     /// Within the LSP, check if a key exists.
     /// It may not exist within `if False:` or `if sys.version == 0:` style code.
     pub fn is_valid_key(&self, k: &Key) -> bool {
@@ -1109,6 +1141,12 @@ impl Bindings {
         use_shape_comments_and_stubs: bool,
     ) -> Self {
         let module_range = x.range;
+        let dunder_all_entries = exports
+            .dunder_all_names()
+            .filter_map(|(_, name, content_range)| {
+                Some(Identifier::new(name.clone(), content_range?))
+            })
+            .collect();
         let pytest_info = PytestBindingInfo::from_module(&x);
         let errors = ErrorCollector::new(module_info.dupe(), error_style);
         let shape_comments = if use_shape_comments_and_stubs {
@@ -1287,7 +1325,7 @@ impl Bindings {
                 classes: builder.django_relation_classes.into_boxed_slice(),
             },
         );
-        Self {
+        let mut bindings = Self {
             module_info,
             parse_errors,
             binding_errors: builder.errors.finish(),
@@ -1297,6 +1335,8 @@ impl Bindings {
             module_ranges,
             annotated_metadata_ranges: merge_ranges(builder.annotated_metadata_ranges),
             docstring_type_ranges: merge_ranges(builder.docstring_type_ranges),
+            dunder_all_entries,
+            dunder_slots_entries: Vec::new(),
             scope_trace: if enable_trace {
                 Some(scope_trace)
             } else {
@@ -1321,7 +1361,28 @@ impl Bindings {
             subsequently_initialized: builder.subsequently_initialized,
             promote_ranges: builder.promote_ranges,
             functools_wrapper_mutation,
-        }
+        };
+        bindings.dunder_slots_entries = bindings
+            .keys::<KeyClassField>()
+            .flat_map(|idx| {
+                let field = bindings.get(idx);
+                if field.name != *dunder::SLOTS {
+                    return Vec::new();
+                }
+                field
+                    .explicit_slots()
+                    .into_iter()
+                    .flatten()
+                    .filter_map(|(name, range)| {
+                        Some(SlotEntry {
+                            name: Identifier::new(name, range?),
+                            class_idx: field.class_idx,
+                        })
+                    })
+                    .collect()
+            })
+            .collect();
+        bindings
     }
 
     fn should_emit_semantic_syntax_error(error: &SemanticSyntaxError) -> bool {