[bz5440307] ac.composite.execute() fails with an empty children list

[add0n]

If you pass an empty object for the children property in your cfg to ac.composite.execute(), Mojito will sort of just hang there. I think I've tracked the issue down to lines 260-262 of composite.common.js (in the function AdapterBuffer.done).

What I think happens is that the buffer.counter property will start at 0, and gets decremented to -1:

if(--this.buffer.counter === 0){
this.callback();
}

... so this.callback() will never execute. In my case, I'd greatly prefer it if it checked for counter <= 0 instead of === 0, so that it could handle empty children objects elegantly.

FYI, my current workaround is to include a dummy child that won't get output anywhere.

[imalberto]

Is a composite mojit with no "children" considered valid configuration ?
If not, then perhaps do the same check as in ac.composite.done() and throw an error if size is 0.

[caridy]

            if (!children || Y.Object.size(children) === 0) {
                throw new Error('Cannot run composite mojit children because' +
                                ' there are no children defined in the' +
                                ' composite mojit spec.');
            }

In 0.5.x we have that check in place.