fix: Allow use as self in method call after unbinding

Author: eliassjogreen

nova_lint/src/immediately_bind_scoped.rs

@@ -161,6 +161,32 @@ fn is_valid_use_of_unbound_value(cx: &LateContext<'_>, expr: &Expr, hir_id: HirI
         return true;
     }
 
+    // If this is the self value of a method call, it's valid
+    if path_to_local_id(expr, hir_id) && is_in_self_position(cx, expr) {
+        return true;
+    }
+
+    false
+}
+
+fn is_in_self_position(cx: &LateContext<'_>, expr: &Expr) -> bool {
+    let mut current_expr = expr;
+
+    // Walk up the parent chain to see if we're in a method call
+    while let Some(parent) = get_parent_expr(cx, current_expr) {
+        match parent.kind {
+            // If we find a method call where our expression is in the receiver position
+            ExprKind::MethodCall(_, receiver, args, _) => {
+                if receiver.hir_id == current_expr.hir_id {
+                    return true;
+                }
+            }
+            // Continue walking up for other expression types
+            _ => {}
+        }
+        current_expr = parent;
+    }
+
     false
 }
 

nova_lint/ui/immediately_bind_scoped.rs

@@ -3,8 +3,8 @@
 use nova_vm::{
     ecmascript::{execution::Agent, types::Value},
     engine::{
+        context::{Bindable, GcScope, NoGcScope},
         Scoped,
-        context::{Bindable, NoGcScope},
     },
 };
 
@@ -35,6 +35,19 @@ fn test_scoped_get_can_be_immediately_passed_on(
     test_consumes_unbound_value(a);
 }
 
+fn test_scoped_get_can_be_used_as_self(agent: &Agent, scoped: Scoped<Value>) {
+    scoped.get(agent).is_undefined();
+}
+
+fn test_scoped_get_can_be_used_as_self_immediately_after(
+    agent: &Agent,
+    scoped: Scoped<Value>,
+    gc: NoGcScope,
+) {
+    let a = scoped.get(agent);
+    a.is_undefined();
+}
+
 fn test_consumes_unbound_value(value: Value) {
     unimplemented!()
 }
@@ -55,6 +68,30 @@ fn test_improbable_but_technically_bad_situation(
     let _a = Scoped::new(agent, Value::Undefined, gc).get(agent);
 }
 
+// fn take_and_return_value_with_gc<'gc>(
+//     agent: &mut Agent,
+//     value: Value,
+//     mut gc: GcScope<'gc, '_>,
+// ) -> Value<'gc> {
+//     Value::Undefined
+// }
+
+// fn test_scoped_used_twice_right_after<'gc>(
+//     agent: &mut Agent,
+//     value: Scoped<Value>,
+//     mut gc: GcScope<'gc, '_>,
+// ) {
+//     let value = value.get(agent);
+//     let something = if value.is_undefined() {
+//         true
+//     } else {
+//         take_and_return_value_with_gc(agent, value, gc.reborrow())
+//             .unbind()
+//             .bind(gc.nogc())
+//             .is_undefined()
+//     };
+// }
+
 fn main() {
     unimplemented!()
 }

nova_lint/ui/immediately_bind_scoped.stderr

@@ -1,5 +1,5 @@
 error: the result of `Scoped<Value>::get` should be immediately bound
-  --> $DIR/immediately_bind_scoped.rs:43:14
+  --> $DIR/immediately_bind_scoped.rs:56:14
    |
 LL |     let _a = scoped.get(agent);
    |              ^^^^^^^^^^^^^^^^^
@@ -8,7 +8,7 @@ LL |     let _a = scoped.get(agent);
    = note: `#[deny(immediately_bind_scoped)]` on by default
 
 error: the result of `Scoped<Value>::get` should be immediately bound
-  --> $DIR/immediately_bind_scoped.rs:55:14
+  --> $DIR/immediately_bind_scoped.rs:68:14
    |
 LL |     let _a = Scoped::new(agent, Value::Undefined, gc).get(agent);
    |              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^