[domains] domain.intercept - remove err argument from cb function

[wavded]

Just throwing it out there for discussion. Been reviewing domains in 0.7.x and really glad we are getting them! Good work.

One API thing at the moment has bugged a me a few times that I thought it would be worth a discussion regardless of the outcome (and at the very least would help me understand the current design choices).

Right now domain.intercept takes a callback that includes the err argument but from what I see in the code (https://github.com/joyent/node/blob/master/lib/domain.js#L142-177) that error argument will always be null if it makes it that far. Why not remove it entirely to give the user a tip off that intercept is actually taking care of that?

e.g.

var d = domain.create()
d.on('error', function (err) { /* handle errors */ })

fs.readFile('./foo', d.intercept(function (data) {
   // do something with successfully returned data
}));

[isaacs]

Yeah, that's a good point.

Wanna write a patch? Should be pretty simple.

[wavded]

Sure can.

[wavded]

@isaacs made a pull request and it was my first time for this project :) so if I need to change anything or do more or less let me know, tried to follow guidelines on the wiki.

[isaacs]

@wavded I was just about to ask that you sign the CLA, but I see you just did :)

I'll review this soon for the next 0.7 release.

[wavded]

Sounds good, thanks @isaacs!