v8 module: allow TypedArray and DataView

[oyyd]

This commit allow passing TypedArray and DataView to:

• v8.deserialize()
• new v8.Deserializer()
• v8.serializer.writeRawBytes()

Refs: #1826

Checklist

• make -j4 test (UNIX), or vcbuild test (Windows) passes
• tests and/or benchmarks are included
• documentation is changed or added
• commit message follows commit guidelines

[vsemozhetbyt]

CI: https://ci.nodejs.org/job/node-test-pull-request/18218/

[refack]

Nits made me ask a question about timing.

[refack]

Please const

[refack]

Could these be const length2 and const buf2 please?
Recycling variables should be avoided.

[refack]

Could this be const arrayBufferViewsLength instead.
.
.
.
Which made be think isn't there a race here?
Is the callbacks guaranteed to be in order?
At minimum this should be documented in a comment

[oyyd]

Is the callbacks guaranteed to be in order?

Yes. We have only one HostObject so that the callback will be called only once.

I think v8.Serializer.writeRawBytes() being expected to be called inside of the callback of _writeHostObject makes the test a bit confusing. I'm going to refactor this.

[refack]

@oyyd as alway thank you for the contribution. While reviewing the code and looking at cases of variable recycling I found that I don't understand the operation order guarantee.
IMHO we should find a way to explicitly test for that, and document that.

[refack]

Maybe simplest solution is to add a sentinel:

  let has_writeHostObjectCalled = false;

the in _writeHostObject

  has_writeHostObjectCalled = true;

the first line of _readHostObject

  assert.ok(has_writeHostObjectCalled);

[refack]

or dual use arrayBufferViewsLength - initialise it to false, and then assert

  des._readHostObject = common.mustCall(() => {
    assert.notStrictEqual(false, arrayBufferViewsLength);
...

[oyyd]

@refack Thanks for your advice! Comments addressed.

I have separated the test for v8.Serializer.writeRawBytes() so that we can avoid recycling variables and the tests for TypedArray and DateView should be clearer. I have also added an assertion to ensure that _writeHostObject is called before _readHostObject.

[refack]

@refack Thanks for your advice! Comments addressed.

Looks 💯. Thank you for following up!

[refack]

CI: https://ci.nodejs.org/job/node-test-pull-request/18228/

[refack]

Landed in 56881b0 🎉