1 files changed, 64 insertions, 0 deletions
diff --git a/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/unregister/unregister-symbol-token.js b/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/unregister/unregister-symbol-token.js
new file mode 100644
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--- /dev/null
+++ b/js/src/tests/test262/built-ins/FinalizationRegistry/prototype/unregister/unregister-symbol-token.js
@@ -0,0 +1,64 @@
+// |reftest| shell-option(--enable-symbols-as-weakmap-keys) skip-if(release_or_beta||!this.hasOwnProperty('FinalizationRegistry')||!xulRuntime.shell) -- symbols-as-weakmap-keys is not released yet, FinalizationRegistry is not enabled unconditionally, requires shell-options
+// Copyright (C) 2022 Igalia, S.L. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+esid: sec-finalization-registry.prototype.unregister
+description: >
+  Return boolean values indicating unregistering of values with Symbol token
+info: |
+  FinalizationRegistry.prototype.unregister ( _unregisterToken_ )
+  4. Let _removed_ be *false*.
+  5. For each Record { [[WeakRefTarget]], [[HeldValue]], [[UnregisterToken]] }
+    _cell_ of _finalizationRegistry_.[[Cells]], do
+    a. If _cell_.[[UnregisterToken]] is not ~empty~ and
+      SameValue(_cell_.[[UnregisterToken]], _unregisterToken_) is *true*, then
+      i. Remove _cell_ from _finalizationRegistry_.[[Cells]].
+      ii. Set _removed_ to *true*.
+  6. Return _removed_.
+features: [FinalizationRegistry, Symbol, symbols-as-weakmap-keys]
+---*/
+
+var fn = function() {};
+var reg = new FinalizationRegistry(fn);
+
+var target1 = {};
+var target2 = {};
+var target3 = {};
+var token = Symbol('unregister');
+
+assert.sameValue(reg.unregister(token), false, 'unregistering regular symbol from empty registry');
+assert.sameValue(reg.unregister(Symbol.hasInstance), false, 'unregistering well-known symbol from empty registry');
+
+reg.register(target1, undefined, token);
+reg.register(target1, undefined, token); // Repeat registering on purpose
+reg.register(target2, undefined, Symbol.hasInstance);
+reg.register(target3, undefined, Symbol.hasInstance);
+
+assert.sameValue(reg.unregister(token), true, 'unregistering regular symbol from finalization registry');
+assert.sameValue(reg.unregister(token), false, 'unregistering regular symbol again from finalization registry');
+assert.sameValue(
+  reg.unregister(Symbol.hasInstance),
+  true,
+  'unregistering well-known symbol to remove target2 and target3'
+);
+assert.sameValue(
+  reg.unregister(Symbol.hasInstance),
+  false,
+  'unregistering well-known again from finalization registry'
+);
+
+// Notice these assertions take advantage of adding targets previously added
+// with a token, but now they have no token so it won't be used to remove them.
+reg.register(target1, token); // heldValue, not unregisterToken
+reg.register(target2, Symbol.hasInstance); // heldValue, not unregisterToken
+reg.register(target3);
+
+assert.sameValue(reg.unregister(token), false, 'nothing to remove with regular symbol unregister token');
+assert.sameValue(
+  reg.unregister(Symbol.hasInstance),
+  false,
+  'nothing to remove with well-known symbol unregister token'
+);
+
+reportCompare(0, 0);