1 files changed, 51 insertions, 0 deletions
diff --git a/testing/web-platform/tests/js/builtins/weakrefs/cleanup-prevented-with-reference.optional.any.js b/testing/web-platform/tests/js/builtins/weakrefs/cleanup-prevented-with-reference.optional.any.js
new file mode 100644
index 0000000000..da902ac4f1
--- /dev/null
+++ b/testing/web-platform/tests/js/builtins/weakrefs/cleanup-prevented-with-reference.optional.any.js
@@ -0,0 +1,51 @@
+// META: script=/common/gc.js
+// META: script=resources/maybe-garbage-collect.js
+// ├──> maybeGarbageCollectAndCleanupAsync
+// └──> resolveGarbageCollection
+/*---
+esid: sec-finalization-registry.prototype.cleanupSome
+info: |
+  FinalizationRegistry.prototype.cleanupSome ( [ callback ] )
+
+  1. Let finalizationRegistry be the this value.
+  2. If Type(finalizationRegistry) is not Object, throw a TypeError exception.
+  3. If finalizationRegistry does not have a [[Cells]] internal slot, throw a TypeError exception.
+  4. If callback is not undefined and IsCallable(callback) is false, throw a TypeError exception.
+  5. Perform ? CleanupFinalizationRegistry(finalizationRegistry, callback).
+  6. Return undefined.
+---*/
+
+let holdingsList = [];
+function cb(holding) {
+  holdingsList.push(holding);
+};
+let finalizationRegistry = new FinalizationRegistry(function() {});
+
+let referenced = {};
+
+function emptyCells() {
+  let target = {};
+  finalizationRegistry.register(target, 'target!');
+  finalizationRegistry.register(referenced, 'referenced');
+
+  let prom = maybeGarbageCollectAndCleanupAsync(target);
+  target = null;
+
+  return prom;
+}
+
+promise_test(() => {
+  return (async () => {
+    assert_implements(
+      typeof FinalizationRegistry.prototype.cleanupSome === 'function',
+      'FinalizationRegistry.prototype.cleanupSome is not implemented.'
+    );
+
+    await emptyCells();
+    finalizationRegistry.cleanupSome(cb);
+
+    assert_equals(holdingsList.length, 1);
+    assert_equals(holdingsList[0], 'target!');
+    assert_equals(typeof referenced, 'object', 'referenced preserved');
+  })().catch(resolveGarbageCollection);
+}, 'cleanupCallback has only one optional chance to be called for a GC that cleans up a registered target.');