[ty] Don't show hover for expressions with no inferred type (#21924)

crates/ty_ide/src/goto.rs

@@ -295,7 +295,7 @@ impl<'db> Definitions<'db> {
 
 impl GotoTarget<'_> {
     pub(crate) fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
-        let ty = match self {
+        match self {
             GotoTarget::Expression(expression) => expression.inferred_type(model),
             GotoTarget::FunctionDef(function) => function.inferred_type(model),
             GotoTarget::ClassDef(class) => class.inferred_type(model),
@@ -317,7 +317,7 @@ impl GotoTarget<'_> {
             } => {
                 // We don't currently support hovering the bare `.` so there is always a name
                 let module = import_name(module_name, *component_index);
-                model.resolve_module_type(Some(module), *level)?
+                model.resolve_module_type(Some(module), *level)
             }
             GotoTarget::StringAnnotationSubexpr {
                 string_expr,
@@ -334,16 +334,16 @@ impl GotoTarget<'_> {
                 } else {
                     // TODO: force the typechecker to tell us its secrets
                     // (it computes but then immediately discards these types)
-                    return None;
+                    None
                 }
             }
             GotoTarget::BinOp { expression, .. } => {
                 let (_, ty) = ty_python_semantic::definitions_for_bin_op(model, expression)?;
-                ty
+                Some(ty)
             }
             GotoTarget::UnaryOp { expression, .. } => {
                 let (_, ty) = ty_python_semantic::definitions_for_unary_op(model, expression)?;
-                ty
+                Some(ty)
             }
             // TODO: Support identifier targets
             GotoTarget::PatternMatchRest(_)
@@ -353,10 +353,8 @@ impl GotoTarget<'_> {
             | GotoTarget::TypeParamParamSpecName(_)
             | GotoTarget::TypeParamTypeVarTupleName(_)
             | GotoTarget::NonLocal { .. }
-            | GotoTarget::Globals { .. } => return None,
+            | GotoTarget::Globals { .. } => None,
-        };
+        }
-
-        Some(ty)
     }
 
     /// Try to get a simplified display of this callable type by resolving overloads

crates/ty_ide/src/hover.rs

@@ -3610,6 +3610,20 @@ def function():
         ");
     }
 
+    #[test]
+    fn hover_tuple_assignment_target() {
+        let test = CursorTest::builder()
+            .source(
+                "test.py",
+                r#"
+                (x, y)<CURSOR> = "test", 10
+                "#,
+            )
+            .build();
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
     impl CursorTest {
         fn hover(&self) -> String {
             use std::fmt::Write;

crates/ty_ide/src/inlay_hints.rs

@@ -362,8 +362,9 @@ impl<'a> SourceOrderVisitor<'a> for InlayHintVisitor<'a, '_> {
             Expr::Name(name) => {
                 if let Some(rhs) = self.assignment_rhs {
                     if name.ctx.is_store() {
-                        let ty = expr.inferred_type(&self.model);
+                        if let Some(ty) = expr.inferred_type(&self.model) {
-                        self.add_type_hint(expr, rhs, ty, !self.in_no_edits_allowed);
+                            self.add_type_hint(expr, rhs, ty, !self.in_no_edits_allowed);
+                        }
                     }
                 }
                 source_order::walk_expr(self, expr);
@@ -371,8 +372,9 @@ impl<'a> SourceOrderVisitor<'a> for InlayHintVisitor<'a, '_> {
             Expr::Attribute(attribute) => {
                 if let Some(rhs) = self.assignment_rhs {
                     if attribute.ctx.is_store() {
-                        let ty = expr.inferred_type(&self.model);
+                        if let Some(ty) = expr.inferred_type(&self.model) {
-                        self.add_type_hint(expr, rhs, ty, !self.in_no_edits_allowed);
+                            self.add_type_hint(expr, rhs, ty, !self.in_no_edits_allowed);
+                        }
                     }
                 }
                 source_order::walk_expr(self, expr);

crates/ty_ide/src/semantic_tokens.rs

@@ -273,7 +273,7 @@ impl<'db> SemanticTokenVisitor<'db> {
         }
 
         // Fall back to type-based classification.
-        let ty = name.inferred_type(self.model);
+        let ty = name.inferred_type(self.model).unwrap_or(Type::unknown());
         let name_str = name.id.as_str();
         self.classify_from_type_and_name_str(ty, name_str)
     }
@@ -302,7 +302,9 @@ impl<'db> SemanticTokenVisitor<'db> {
                 let parsed = parsed_module(db, definition.file(db));
                 let ty = parameter.node(&parsed.load(db)).inferred_type(&model);
 
-                if let Type::TypeVar(type_var) = ty {
+                if let Some(ty) = ty
+                    && let Type::TypeVar(type_var) = ty
+                {
                     match type_var.typevar(db).kind(db) {
                         TypeVarKind::TypingSelf => {
                             return Some((SemanticTokenType::SelfParameter, modifiers));
@@ -344,9 +346,9 @@ impl<'db> SemanticTokenVisitor<'db> {
                     _ => None,
                 };
 
-                if let Some(value) = value {
+                if let Some(value) = value
-                    let value_ty = value.inferred_type(&model);
+                    && let Some(value_ty) = value.inferred_type(&model)
-
+                {
                     if value_ty.is_class_literal()
                         || value_ty.is_subclass_of()
                         || value_ty.is_generic_alias()
@@ -710,12 +712,12 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
                 for alias in &import.names {
                     if let Some(asname) = &alias.asname {
                         // For aliased imports (from X import Y as Z), classify Z based on what Y is
-                        let ty = alias.inferred_type(self.model);
+                        let ty = alias.inferred_type(self.model).unwrap_or(Type::unknown());
                         let (token_type, modifiers) = self.classify_from_alias_type(ty, asname);
                         self.add_token(asname, token_type, modifiers);
                     } else {
                         // For direct imports (from X import Y), use semantic classification
-                        let ty = alias.inferred_type(self.model);
+                        let ty = alias.inferred_type(self.model).unwrap_or(Type::unknown());
                         let (token_type, modifiers) =
                             self.classify_from_alias_type(ty, &alias.name);
                         self.add_token(&alias.name, token_type, modifiers);
@@ -835,7 +837,7 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
                 self.visit_expr(&attr.value);
 
                 // Then add token for the attribute name (e.g., 'path' in 'os.path')
-                let ty = expr.inferred_type(self.model);
+                let ty = expr.inferred_type(self.model).unwrap_or(Type::unknown());
                 let (token_type, modifiers) =
                     Self::classify_from_type_for_attribute(ty, &attr.attr);
                 self.add_token(&attr.attr, token_type, modifiers);

crates/ty_python_semantic/src/semantic_model.rs

@@ -196,7 +196,10 @@ impl<'db> SemanticModel<'db> {
 
     /// Returns completions for symbols available in a `object.<CURSOR>` context.
     pub fn attribute_completions(&self, node: &ast::ExprAttribute) -> Vec<Completion<'db>> {
-        let ty = node.value.inferred_type(self);
+        let Some(ty) = node.value.inferred_type(self) else {
+            return Vec::new();
+        };
+
         all_members(self.db, ty)
             .into_iter()
             .map(|member| Completion {
@@ -400,7 +403,7 @@ pub trait HasType {
     ///
     /// ## Panics
     /// May panic if `self` is from another file than `model`.
-    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db>;
+    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>>;
 }
 
 pub trait HasDefinition {
@@ -412,18 +415,16 @@ pub trait HasDefinition {
 }
 
 impl HasType for ast::ExprRef<'_> {
-    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db> {
+    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
         let index = semantic_index(model.db, model.file);
         // TODO(#1637): semantic tokens is making this crash even with
         // `try_expr_ref_in_ast` guarding this, for now just use `try_expression_scope_id`.
         // The problematic input is `x: "float` (with a dangling quote). I imagine the issue
         // is we're too eagerly setting `is_string_annotation` in inference.
-        let Some(file_scope) = index.try_expression_scope_id(&model.expr_ref_in_ast(*self)) else {
+        let file_scope = index.try_expression_scope_id(&model.expr_ref_in_ast(*self))?;
-            return Type::unknown();
-        };
         let scope = file_scope.to_scope_id(model.db, model.file);
 
-        infer_scope_types(model.db, scope).expression_type(*self)
+        infer_scope_types(model.db, scope).try_expression_type(*self)
     }
 }
 
@@ -431,7 +432,7 @@ macro_rules! impl_expression_has_type {
     ($ty: ty) => {
         impl HasType for $ty {
             #[inline]
-            fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db> {
+            fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
                 let expression_ref = ExprRef::from(self);
                 expression_ref.inferred_type(model)
             }
@@ -474,7 +475,7 @@ impl_expression_has_type!(ast::ExprSlice);
 impl_expression_has_type!(ast::ExprIpyEscapeCommand);
 
 impl HasType for ast::Expr {
-    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db> {
+    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
         match self {
             Expr::BoolOp(inner) => inner.inferred_type(model),
             Expr::Named(inner) => inner.inferred_type(model),
@@ -525,9 +526,9 @@ macro_rules! impl_binding_has_ty_def {
 
         impl HasType for $ty {
             #[inline]
-            fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db> {
+            fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
                 let binding = HasDefinition::definition(self, model);
-                binding_type(model.db, binding)
+                Some(binding_type(model.db, binding))
             }
         }
     };
@@ -541,12 +542,12 @@ impl_binding_has_ty_def!(ast::ExceptHandlerExceptHandler);
 impl_binding_has_ty_def!(ast::TypeParamTypeVar);
 
 impl HasType for ast::Alias {
-    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db> {
+    fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Option<Type<'db>> {
         if &self.name == "*" {
-            return Type::Never;
+            return Some(Type::Never);
         }
         let index = semantic_index(model.db, model.file);
-        binding_type(model.db, index.expect_single_definition(self))
+        Some(binding_type(model.db, index.expect_single_definition(self)))
     }
 }
 
@@ -584,7 +585,7 @@ mod tests {
 
         let function = ast.suite()[0].as_function_def_stmt().unwrap();
         let model = SemanticModel::new(&db, foo);
-        let ty = function.inferred_type(&model);
+        let ty = function.inferred_type(&model).unwrap();
 
         assert!(ty.is_function_literal());
 
@@ -603,7 +604,7 @@ mod tests {
 
         let class = ast.suite()[0].as_class_def_stmt().unwrap();
         let model = SemanticModel::new(&db, foo);
-        let ty = class.inferred_type(&model);
+        let ty = class.inferred_type(&model).unwrap();
 
         assert!(ty.is_class_literal());
 
@@ -624,7 +625,7 @@ mod tests {
         let import = ast.suite()[0].as_import_from_stmt().unwrap();
         let alias = &import.names[0];
         let model = SemanticModel::new(&db, bar);
-        let ty = alias.inferred_type(&model);
+        let ty = alias.inferred_type(&model).unwrap();
 
         assert!(ty.is_class_literal());
 

crates/ty_python_semantic/src/types.rs

@@ -878,7 +878,7 @@ impl<'db> Type<'db> {
         Self::Dynamic(DynamicType::Any)
     }
 
-    pub(crate) const fn unknown() -> Self {
+    pub const fn unknown() -> Self {
         Self::Dynamic(DynamicType::Unknown)
     }
 

crates/ty_python_semantic/src/types/ide_support.rs

@@ -155,7 +155,8 @@ pub fn definitions_for_name<'db>(
         // https://typing.python.org/en/latest/spec/special-types.html#special-cases-for-float-and-complex
         if matches!(name_str, "float" | "complex")
             && let Some(expr) = node.expr_name()
-            && let Some(union) = expr.inferred_type(&SemanticModel::new(db, file)).as_union()
+            && let Some(ty) = expr.inferred_type(model)
+            && let Some(union) = ty.as_union()
             && is_float_or_complex_annotation(db, union, name_str)
         {
             return union
@@ -234,7 +235,10 @@ pub fn definitions_for_attribute<'db>(
     let mut resolved = Vec::new();
 
     // Determine the type of the LHS
-    let lhs_ty = attribute.value.inferred_type(model);
+    let Some(lhs_ty) = attribute.value.inferred_type(model) else {
+        return resolved;
+    };
+
     let tys = match lhs_ty {
         Type::Union(union) => union.elements(model.db()).to_vec(),
         _ => vec![lhs_ty],
@@ -374,7 +378,9 @@ pub fn definitions_for_keyword_argument<'db>(
     call_expr: &ast::ExprCall,
 ) -> Vec<ResolvedDefinition<'db>> {
     let db = model.db();
-    let func_type = call_expr.func.inferred_type(model);
+    let Some(func_type) = call_expr.func.inferred_type(model) else {
+        return Vec::new();
+    };
 
     let Some(keyword_name) = keyword.arg.as_ref() else {
         return Vec::new();
@@ -498,7 +504,9 @@ pub fn call_signature_details<'db>(
     model: &SemanticModel<'db>,
     call_expr: &ast::ExprCall,
 ) -> Vec<CallSignatureDetails<'db>> {
-    let func_type = call_expr.func.inferred_type(model);
+    let Some(func_type) = call_expr.func.inferred_type(model) else {
+        return Vec::new();
+    };
 
     // Use into_callable to handle all the complex type conversions
     if let Some(callable_type) = func_type
@@ -507,7 +515,9 @@ pub fn call_signature_details<'db>(
     {
         let call_arguments =
             CallArguments::from_arguments(&call_expr.arguments, |_, splatted_value| {
-                splatted_value.inferred_type(model)
+                splatted_value
+                    .inferred_type(model)
+                    .unwrap_or(Type::unknown())
             });
         let bindings = callable_type
             .bindings(model.db())
@@ -564,7 +574,7 @@ pub fn call_type_simplified_by_overloads(
     call_expr: &ast::ExprCall,
 ) -> Option<String> {
     let db = model.db();
-    let func_type = call_expr.func.inferred_type(model);
+    let func_type = call_expr.func.inferred_type(model)?;
 
     // Use into_callable to handle all the complex type conversions
     let callable_type = func_type.try_upcast_to_callable(db)?.into_type(db);
@@ -579,7 +589,9 @@ pub fn call_type_simplified_by_overloads(
 
     // Hand the overload resolution system as much type info as we have
     let args = CallArguments::from_arguments_typed(&call_expr.arguments, |_, splatted_value| {
-        splatted_value.inferred_type(model)
+        splatted_value
+            .inferred_type(model)
+            .unwrap_or(Type::unknown())
     });
 
     // Try to resolve overloads with the arguments/types we have
@@ -612,8 +624,8 @@ pub fn definitions_for_bin_op<'db>(
     model: &SemanticModel<'db>,
     binary_op: &ast::ExprBinOp,
 ) -> Option<(Vec<ResolvedDefinition<'db>>, Type<'db>)> {
-    let left_ty = binary_op.left.inferred_type(model);
+    let left_ty = binary_op.left.inferred_type(model)?;
-    let right_ty = binary_op.right.inferred_type(model);
+    let right_ty = binary_op.right.inferred_type(model)?;
 
     let Ok(bindings) = Type::try_call_bin_op(model.db(), left_ty, binary_op.op, right_ty) else {
         return None;
@@ -639,7 +651,7 @@ pub fn definitions_for_unary_op<'db>(
     model: &SemanticModel<'db>,
     unary_op: &ast::ExprUnaryOp,
 ) -> Option<(Vec<ResolvedDefinition<'db>>, Type<'db>)> {
-    let operand_ty = unary_op.operand.inferred_type(model);
+    let operand_ty = unary_op.operand.inferred_type(model)?;
 
     let unary_dunder_method = match unary_op.op {
         ast::UnaryOp::Invert => "__invert__",