Add tests

Author: jedel1043

core/engine/src/builtins/finalization_registry/mod.rs

@@ -23,11 +23,13 @@ use crate::{
 
 use super::{BuiltInConstructor, BuiltInObject, IntrinsicObject, builder::BuiltInBuilder};
 
+#[cfg(test)]
+mod tests;
+
 /// On GG collection, sends a message to a [`FinalizationRegistry`] indicating that it needs to
 /// be collected.
 #[derive(Trace)]
-#[boa_gc(unsafe_empty_trace)]
-struct CleanupSignaler(Cell<Option<async_channel::WeakSender<()>>>);
+struct CleanupSignaler(#[unsafe_ignore_trace] Cell<Option<async_channel::WeakSender<()>>>);
 
 impl Finalize for CleanupSignaler {
     fn finalize(&self) {
@@ -313,12 +315,7 @@ impl FinalizationRegistry {
                 let _key = cell.target.key();
                 // TODO: it might be better to add a special ref for the value that
                 // also preserves the original key instead.
-                // SAFETY: the original key is alive per our previous call to `key`,
-                // so if this returns `Some`, then the value cannot be collected
-                // until `key` gets dropped.
-                unsafe {
-                    cell.target.value_ref().and_then(|v| v.0.take());
-                }
+                cell.target.value().and_then(|v| v.0.take());
 
                 // ii. Set removed to true.
                 removed = true;

core/engine/src/builtins/finalization_registry/tests.rs

@@ -0,0 +1,21 @@
+use indoc::indoc;
+
+use crate::{TestAction, run_test_actions};
+
+#[test]
+fn finalization_registry_simple() {
+    run_test_actions([
+        TestAction::run(indoc! {r#"
+            let counter = 0;
+            const registry = new FinalizationRegistry(() => {
+                counter++;
+            });
+
+            registry.register(["foo"]);
+        "#}),
+        TestAction::assert_eq("counter", 0),
+        TestAction::inspect_context(|_| boa_gc::force_collect()),
+        TestAction::inspect_context(|ctx| ctx.run_jobs().unwrap()),
+        TestAction::assert_eq("counter", 1),
+    ]);
+}

core/engine/src/builtins/mod.rs

@@ -447,6 +447,7 @@ pub(crate) fn set_default_global_bindings(context: &mut Context) -> JsResult<()>
     global_binding::<WeakSet>(context)?;
     global_binding::<IteratorConstructor>(context)?;
     global_binding::<Atomics>(context)?;
+    global_binding::<FinalizationRegistry>(context)?;
 
     #[cfg(feature = "annex-b")]
     {