[Merged by Bors] - Implement the WeakRef builtin

[jedel1043]

52/60 tests passing. The remaining tests are either features not implemented (FinalizationRegistry) or features still in development (symbols-as-weakmap-keys).

[github-actions]

Test262 conformance changes

Test result	main count	PR count	difference
Total	93,811	93,811	0
Passed	69,562	69,620	+58
Ignored	18,414	18,452	+38
Failed	5,835	5,739	-96
Panics	0	0	0
Conformance	74.15%	74.21%	+0.06%

Fixed tests (58):

test/built-ins/WeakRef/name.js [strict mode] (previously Failed)
test/built-ins/WeakRef/name.js (previously Failed)
test/built-ins/WeakRef/returns-new-object-from-constructor-with-object-target.js [strict mode] (previously Failed)
test/built-ins/WeakRef/returns-new-object-from-constructor-with-object-target.js (previously Failed)
test/built-ins/WeakRef/prop-desc.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prop-desc.js (previously Failed)
test/built-ins/WeakRef/prototype-from-newtarget.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype-from-newtarget.js (previously Failed)
test/built-ins/WeakRef/prototype-from-newtarget-abrupt.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype-from-newtarget-abrupt.js (previously Failed)
test/built-ins/WeakRef/proto-from-ctor-realm.js [strict mode] (previously Failed)
test/built-ins/WeakRef/proto-from-ctor-realm.js (previously Failed)
test/built-ins/WeakRef/newtarget-prototype-is-not-object.js [strict mode] (previously Failed)
test/built-ins/WeakRef/newtarget-prototype-is-not-object.js (previously Failed)
test/built-ins/WeakRef/throws-when-target-cannot-be-held-weakly.js [strict mode] (previously Failed)
test/built-ins/WeakRef/throws-when-target-cannot-be-held-weakly.js (previously Failed)
test/built-ins/WeakRef/length.js [strict mode] (previously Failed)
test/built-ins/WeakRef/length.js (previously Failed)
test/built-ins/WeakRef/undefined-newtarget-throws.js [strict mode] (previously Failed)
test/built-ins/WeakRef/undefined-newtarget-throws.js (previously Failed)
test/built-ins/WeakRef/is-a-constructor.js [strict mode] (previously Failed)
test/built-ins/WeakRef/is-a-constructor.js (previously Failed)
test/built-ins/WeakRef/proto.js [strict mode] (previously Failed)
test/built-ins/WeakRef/proto.js (previously Failed)
test/built-ins/WeakRef/constructor.js [strict mode] (previously Failed)
test/built-ins/WeakRef/constructor.js (previously Failed)
test/built-ins/WeakRef/prototype-from-newtarget-custom.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype-from-newtarget-custom.js (previously Failed)
test/built-ins/WeakRef/instance-extensible.js [strict mode] (previously Failed)
test/built-ins/WeakRef/instance-extensible.js (previously Failed)
test/built-ins/WeakRef/prototype/prop-desc.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/prop-desc.js (previously Failed)
test/built-ins/WeakRef/prototype/Symbol.toStringTag.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/Symbol.toStringTag.js (previously Failed)
test/built-ins/WeakRef/prototype/proto.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/proto.js (previously Failed)
test/built-ins/WeakRef/prototype/constructor.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/constructor.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/name.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/name.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/prop-desc.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/prop-desc.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/this-not-object-throws.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/this-not-object-throws.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/not-a-constructor.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/not-a-constructor.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/length.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/length.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/return-object-target.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/return-object-target.js (previously Failed)
test/built-ins/WeakRef/prototype/deref/custom-this.js [strict mode] (previously Failed)
test/built-ins/WeakRef/prototype/deref/custom-this.js (previously Failed)
test/built-ins/Object/seal/seal-weakref.js [strict mode] (previously Failed)
test/built-ins/Object/seal/seal-weakref.js (previously Failed)
test/language/statements/class/subclass-builtins/subclass-WeakRef.js [strict mode] (previously Failed)
test/language/statements/class/subclass-builtins/subclass-WeakRef.js (previously Failed)
test/language/expressions/class/subclass-builtins/subclass-WeakRef.js [strict mode] (previously Failed)
test/language/expressions/class/subclass-builtins/subclass-WeakRef.js (previously Failed)

[codecov]

Codecov Report

Merging #2438 (379d7e4) into main (98e6dd3) will increase coverage by 0.13%.
The diff coverage is 76.00%.

@@            Coverage Diff             @@
##             main    #2438      +/-   ##
==========================================
+ Coverage   52.41%   52.54%   +0.13%     
==========================================
  Files         329      329              
  Lines       34945    34942       -3     
==========================================
+ Hits        18315    18360      +45     
+ Misses      16630    16582      -48     

Impacted Files	Coverage Δ
boa_engine/src/builtins/array/mod.rs	75.98% <0.00%> (+0.14%)	⬆️
boa_engine/src/builtins/object/mod.rs	60.22% <0.00%> (ø)
boa_engine/src/vm/code_block.rs	33.42% <0.00%> (ø)
boa_engine/src/object/mod.rs	45.98% <72.72%> (+0.32%)	⬆️
boa_engine/src/builtins/weak/weak_ref.rs	73.80% <73.80%> (ø)
boa_engine/src/builtins/mod.rs	98.57% <100.00%> (+0.02%)	⬆️
boa_engine/src/context/intrinsics.rs	98.76% <100.00%> (+0.02%)	⬆️
boa_engine/src/context/mod.rs	65.32% <100.00%> (+0.89%)	⬆️
boa_engine/src/object/jsobject.rs	66.08% <100.00%> (+0.44%)	⬆️
boa_engine/src/value/mod.rs	65.07% <100.00%> (ø)
... and 10 more

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[raskad]

Looks good to me.

I think if we use a forced gc run, we could create a test to make sure that weakrefs are correctly gc'd after a microtask execution, right?

[jedel1043]

Looks good to me.

I think if we use a forced gc run, we could create a test to make sure that weakrefs are correctly gc'd after a microtask execution, right?

Yep. I think the test262 only tests that objects aren't gc'd between derefs on the same script. To test the other half of the API, we'll need to:

• Create a new Context.
• Run a script that uses the API.
• Call force_collect.
• Check that the WeakRef stored in the previous run returns undefined on deref.

I'll add some tests for it.

[HalidOdat]

Looks great to me! :)

[Razican]

Thank you! Just a small question about one piece of code :)

[Razican]

Bors r+

[bors]

Pull request successfully merged into main.

Build succeeded:

• Build and Test (macos-latest)
• Build and Test (windows-latest)
• Coverage
• Misc