1 files changed, 46 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/register/return-undefined-register-object.js b/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/register/return-undefined-register-object.js
new file mode 100644
index 0000000000..b185a37113
--- /dev/null
+++ b/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/register/return-undefined-register-object.js
@@ -0,0 +1,46 @@
+// |reftest| skip-if(!this.hasOwnProperty('FinalizationRegistry')) -- FinalizationRegistry is not enabled unconditionally
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-registry.prototype.register
+description: Return undefined after registering an Object
+info: |
+  FinalizationRegistry.prototype.register ( _target_ , _heldValue_ [, _unregisterToken_ ] )
+  1. Let _finalizationRegistry_ be the *this* value.
+  2. Perform ? RequireInternalSlot(_finalizationRegistry_, [[Cells]]).
+  3. If CanBeHeldWeakly(_target_) is *false*, throw a *TypeError* exception.
+  4. If SameValue(_target_, _heldValue_) is *true*, throw a *TypeError*
+    exception.
+  5. If CanBeHeldWeakly(_unregisterToken_) is *false*,
+    a. If _unregisterToken_ is not *undefined*, throw a *TypeError* exception.
+    b. Set _unregisterToken_ to ~empty~.
+  6. Let _cell_ be the Record { [[WeakRefTarget]]: _target_, [[HeldValue]]:
+    _heldValue_, [[UnregisterToken]]: _unregisterToken_ }.
+  7. Append _cell_ to _finalizationRegistry_.[[Cells]].
+  8. Return *undefined*.
+features: [FinalizationRegistry]
+---*/
+
+var fn = function() {};
+var finalizationRegistry = new FinalizationRegistry(fn);
+
+var target = {};
+assert.sameValue(finalizationRegistry.register(target), undefined, 'Register a target');
+assert.sameValue(finalizationRegistry.register(target), undefined, 'Register the same target again');
+assert.sameValue(finalizationRegistry.register(target), undefined, 'Register the same target again and again');
+
+assert.sameValue(finalizationRegistry.register({}), undefined, 'Register other targets');
+
+assert.sameValue(finalizationRegistry.register(target, undefined, {}), undefined, 'Register target with unregisterToken');
+assert.sameValue(
+  finalizationRegistry.register(target, undefined, target),
+  undefined,
+  'Register target with unregisterToken being the registered target'
+);
+
+assert.sameValue(finalizationRegistry.register(target, undefined, undefined), undefined, 'Register target with explicit undefined unregisterToken');
+
+assert.sameValue(finalizationRegistry.register(fn), undefined, 'register the cleanup callback fn');
+
+reportCompare(0, 0);