In these tests, cleanupSome() would have optionally emptied the
FinalizationRegistry synchronously and called the finalization callbacks.
Without cleanupSome(), there is no way to observe a FinalizationRegistry
being emptied using "pure" ECMAScript: FinalizationRegistry doesn't get
cleaned up until the microtask queue is empty, and without external APIs
such as setTimeout() there is no way to pause execution until after the
microtask queue is empty.
Non-deterministic tests are not that useful anyway; these tests are
probably better left to implementations' internal testing strategies.
This adds tests to WeakMap, WeakSet, WeakRef, and FinalizationRegistry for
Symbols as weakly-held values. Regular symbols and well-known symbols are
both tested. These tests correspond to existing tests for Objects as
weakly-held values, but are put in separate files so that they can be
filtered out with the "symbols-as-weakmap-keys" feature flag.
Registered symbols are not allowed; this is already tested in the "cannot-
be-held-weakly" tests.
See: #2850
There are many existing tests for WeakMap, WeakSet, WeakRef, and
FinalizationRegistry using Objects as weak values. For symbols-as-weakmap-
keys, we'll want to write tests that parallel these for Symbol keys.
Change the descriptions and filenames of these tests to describe their new
scope of only Object weak values.
Update the front matter of these tests while we're at it, to reflect the
changes to the spec text that the symbols-as-weakmap-keys brings in. (In
some cases, remove irrelevant bits of the front matter.)
See: #2850
WeakMap, WeakSet, WeakRef, and FinalizationRegistry all had tests
verifying what would happen if they were called with a value that wasn't
allowed as a weak value: before this proposal, that was a non-Object.
Now, allowed weak values are Objects, well-known Symbols, and unregistered
Symbols. That leaves registered Symbols that are still not allowed as weak
values.
This commit updates those tests to use a registered Symbol instead of an
unregistered Symbol; they should still pass, regardless of whether the
implementation has implemented symbols-as-weakmap-keys yet.
The tests are renamed as appropriate.
Also updates the frontmatter to the most current spec text, including the
CanBeHeldWeakly abstract operation.
See: #2850
The WeakRefs proposal advanced to Stage 4 but cleanupSome moved back to a Stage 2 status.
The tests should remain in Test262 for now but this feature flag should help users to
filter tests out.
Philip Chimento
Kevin Gibbons
snek
Rick Waldron
Rick Waldron
Leo Balter
Shu-yu Guo
Daniel Ehrenberg