1 files changed, 38 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/register/heldValue-same-as-target.js b/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/register/heldValue-same-as-target.js
new file mode 100644
index 0000000000..11c8142074
--- /dev/null
+++ b/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/register/heldValue-same-as-target.js
@@ -0,0 +1,38 @@
+// |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: heldValue may be the same as target
+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.
+features: [FinalizationRegistry, Symbol]
+---*/
+
+var finalizationRegistry = new FinalizationRegistry(function() {});
+
+var target = {};
+assert.throws(TypeError, () => finalizationRegistry.register(target, target));
+
+// The following will throw regardless of whether the implementation supports
+// Symbols as weak values. Step 3 if no, Step 4 if yes.
+
+var symbolTarget = Symbol('a description');
+assert.throws(
+  TypeError,
+  () => finalizationRegistry.register(symbolTarget, symbolTarget),
+  'target and heldValue are the same regular symbol'
+);
+
+assert.throws(
+  TypeError,
+  () => finalizationRegistry.register(Symbol.hasInstance, Symbol.hasInstance),
+  'target and heldValue are the same well-known symbol'
+);
+
+reportCompare(0, 0);