comm-central has a quite useful JS module to deal with arrays and enumerators. I would like to use it for instant messaging code shared between Thunderbird (bug 714733) and Instantbird, but as this module is in comm-central instead of mozilla-central, I would have to fork it in Instantbird's code repository in order to do this, which would be quite sad.

I forgot to also move the tests in the previous patch...

A few comments that could do with being discussed before starting reviews: I'm trying to justify the existence of toArray to myself. Why would you ever use it instead of just directly using [a for (a of foo)]? I'd expect the caller to know what it is dealing with and save us the hassle of flakey duck-typing. fixIterator should be called toJSIterator (as we may well want a toXPCOMIterator at some point). Otherwise this stuff looks sensible, I think we'd want to put it in an IteratorUtils object to match the normal jsms we have in tree (and name the file the same).

Comment on attachment 599094 [details] [diff] [review] Same with tests Review of attachment 599094 [details] [diff] [review]: ----------------------------------------------------------------- I'd like to figure out particularly the first part of my last comment before reviewing this.