Node 6 support.

Github code search reports that there is no use of async or await in koa itself. Therefore, it should work fine in Node 6 (and anecdotally it seems to). Therefore I am struggling to understand the engine restriction on >=7.6 (sorry if I’ve missed something obvious). Obviously middleware authors can require Node > 7.6 if they are going to have async and await directly in npm-published code, but it would be great if Koa itself could relax this restriction for the core if it is unnecessary. My own reasoning is that I’ll be damned if I put non-LTS versions of Node into production.

[jonathanong]

you could just ignore the engine restriction. it would be a bigger issue if someone tried to use koa@2 with async/await on node v6 not knowing that it’s not available on that version of node.

we could drop it, but we’re not going to bother adding babel as a dev dependency just to support v6.

[bttmly]

Further, it seems weird to insist users use async/await – Koa works perfectly fine with Promises and indeed, even without async/await I find the Koa middleware model far superior to Express/Connect.

As for the worry of someone running koa@2 in an environment that doesn’t support async/await, it doesn’t seem like it should be the library’s responsibility for ensuring developers know the features of then own platform. I think disclaimer in the docs about Node versions that support async/await and a note that Promises can be used instead should be sufficient.