mozilla-central/testing/web-platform/tests/js/builtins/weakrefs/unregister-cleaned-up-cell.optional.any.js (file symbol)

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Test Info: Warnings

// META: script=/common/gc.js
// META: script=resources/maybe-garbage-collect.js
// ├──> maybeGarbageCollectAndCleanupAsync
// └──> resolveGarbageCollection
/*---
esid: sec-finalization-registry.prototype.unregister
info: |
FinalizationRegistry.prototype.cleanupSome ( [ callback ] )
1. Let finalizationRegistry be the this value.
...
5. Perform ! CleanupFinalizationRegistry(finalizationRegistry, callback).
...
CleanupFinalizationRegistry ( finalizationRegistry [ , callback ] )
...
3. While finalizationRegistry.[[Cells]] contains a Record cell such that cell.[[WeakRefTarget]] is ~empty~, then an implementation may perform the following steps,
a. Choose any such cell.
b. Remove cell from finalizationRegistry.[[Cells]].
c. Perform ? Call(callback, undefined, << cell.[[HeldValue]] >>).
...
FinalizationRegistry.prototype.unregister ( unregisterToken )
1. Let removed be false.
2. For each Record { [[Target]], [[Holdings]], [[UnregisterToken]] } cell that is an element of finalizationRegistry.[[Cells]], do
a. If SameValue(cell.[[UnregisterToken]], unregisterToken) is true, then
i. Remove cell from finalizationRegistry.[[Cells]].
ii. Set removed to true.
3. Return removed.
---*/
let value = 'target!';
let token = {};
let finalizationRegistry = new FinalizationRegistry(function() {});
function emptyCells() {
let target = {};
finalizationRegistry.register(target, value, token);
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();
let called = 0;
let holdings = [];
finalizationRegistry.cleanupSome((holding) => {
called += 1;
holdings.push(holding);
});
assert_equals(called, 1);
assert_equals(holdings.length, 1);
assert_equals(holdings[0], value);
let res = finalizationRegistry.unregister(token);
assert_equals(res, false, 'unregister after iterating over it in cleanup');
})().catch(resolveGarbageCollection);
}, 'Cannot unregister a cell that has been cleaned up');