[ty] hotfix panic in semantic tokens

crates/ty_ide/src/semantic_tokens.rs

@@ -1579,6 +1579,8 @@ z = "int"
 w1: "int | str" = "hello"
 w2: "int | sr" = "hello"
 w3: "int | " = "hello"
+w4: "float"
+w5: "float
 "#,
         );
 
@@ -1604,6 +1606,10 @@ w3: "int | " = "hello"
         "w3" @ 86..88: Variable [definition]
         "\"int | \"" @ 90..98: String
         "\"hello\"" @ 101..108: String
+        "w4" @ 109..111: Variable [definition]
+        "float" @ 114..119: Class
+        "w5" @ 121..123: Variable [definition]
+        "float" @ 126..131: Class
         "#);
     }
 

crates/ty_python_semantic/src/semantic_model.rs

@@ -408,7 +408,13 @@ pub trait HasDefinition {
 impl HasType for ast::ExprRef<'_> {
     fn inferred_type<'db>(&self, model: &SemanticModel<'db>) -> Type<'db> {
         let index = semantic_index(model.db, model.file);
-        let file_scope = index.expression_scope_id(&model.expr_ref_in_ast(*self));
+        // 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 {
+            return Type::unknown();
+        };
         let scope = file_scope.to_scope_id(model.db, model.file);
 
         infer_scope_types(model.db, scope).expression_type(*self)