Receiver parameter for CallAsFunction should be Local<Value>

[cscott]

The receiver can be null, so the receiver parameter for Nan::CallAsFunction should be Local<Value> not Local<Object>. The parameter is declared as Local<Value> in v8, it's just Nan which has the overly-restrictive type.

[kkoopa]

No.

On October 21, 2015 9:47:07 AM GMT+03:00, "C. Scott Ananian" notifications@github.com wrote:

The receiver can be null, so the receiver parameter for
Nan::CallAsFunction should be Local<Value> not Local<Object>.
The parameter is declared as Local<Value> in v8, it's just Nan which
has the overly-restrictive type.

---

Reply to this email directly or view it on GitHub:
#497

[cscott]

Hm. JavaScript has changed since the node 0.8.x days.

[kkoopa]

Try telling that to the holdouts who refuse to upgrade. Here I am, seemingly stuck with supporting outdated software until the heat death of the universe. The same goes for 0.10.

[bnoordhuis]

It would be possible to emulate it for older versions with something like this:

Local<Value> recv = /* ... */;
Local<Object> recv_obj;
if (recv->IsUndefined() || recv->IsNull()) {
  recv_obj = Context::Global();
} else {
  recv_obj = recv->ToObject();
}

The IsUndefined() and IsNull() checks are cheap, probably cheaper than putting in an extra if (recv->IsObject()) for the common case.

[kkoopa]

Interesting. Would this apply to all the other function-related stuff which has
the same problem?

On Wednesday 21 October 2015 02:47:00 Ben Noordhuis wrote:

It would be possible to emulate it for older versions with something like
this:

Local<Value> recv = /* ... */;
Local<Object> recv_obj;
if (recv->IsUndefined() || recv->IsNull()) {
  recv_obj = Context::Global();
} else {
  recv_obj = recv->ToObject();
}

The IsUndefined() and IsNull() checks are cheap, probably cheaper than
putting in an extra if (recv->IsObject()) for the common case.

---

Reply to this email directly or view it on GitHub:
#497 (comment)

[bnoordhuis]

What function-related stuff is that? My comment was mostly in the context of Function::Call().

[kkoopa]

I seem to remember a couple other places where there has been a change from Object to Value. Some in V8 some in Node. Maybe MakeCallback? I think there was a bunch of stuff that eventually boiled down to Function::Call.

On October 21, 2015 12:58:33 PM GMT+03:00, Ben Noordhuis notifications@github.com wrote:

What function-related stuff is that? My comment was mostly in the
context of Function::Call().

---

Reply to this email directly or view it on GitHub:
#497 (comment)

[bnoordhuis]

Oh, like that. Yes, for consistency the nan wrapper for node::MakeCallback() should get the same treatment.

[kkoopa]

After grepping for v8::Object it seems these are the ones that need updating:
CallAsFunction
MakeCallback
Callback::Call
Callback::operator()
Call #496

[cscott]

It would be nice to ensure that (5).toString() works as well -- I'm not sure if ToObject (as @bnoordhuis wrote above) does the full object conversion for primitives.

[kkoopa]

Primitive is-a Value which is where ToObject is defined. It's a v8 bug if it does not work.

[bnoordhuis]

I'm not sure if ToObject (as @bnoordhuis wrote above) does the full object conversion for primitives.

It does (or should - like @kkoopa said, it's a V8 bug if it doesn't.)

[kkoopa]

http://www.ecma-international.org/ecma-262/5.1/#sec-9.9

[kkoopa]

Could not come up with a way to handle the differences between strict and sloppy mode correctly, so this cannot be done until 0.10 support is dropped.