(req, res) signature

[jonathanong]

reopening a clean issue. references: #34 #36

[jonathanong]

since we're doing this.request and this.response, would be nice if the signature was:

app.use(function* (req, res) {
  assert(this.request === req);
  assert(this.response === res);
})

because doing this.request and this.response or var req = this.request would be pretty annoying. of course this shouldn't be necessary since a lot of properties are delegated to this, but i don't see the harm of passing these as arguments. it would also make it more similar to express, especially if you decided to make express 4.0 an opinionated version of koa.

[jonathanong]

possible implementation: koajs/compose#1

variable arity would be pretty simple to do if we compose this way.

[tj]

the one thing I like about not using arguments at all is that it frees up args for stuff like koa-route parameters. which could still use this.request but then it kind of diverges more from other koa related code, but definitely worth a consideration it does look better than if (this.response.header[blahblah]). The other reason I like it being on this is that it's reasonably obvious that those are not node's request/response objects since it doesn't match express

hopefully we don't even use those very much in every-day koa code, it just gets awkward with a few of those properties we had. On the other hand I'm totally cool with just doing this.params again in koa-route, not a huge deal

[jonathanong]

hmmm i'm actually liking doing this.request and this.response and it's probably better for users not to worry about arity (as you know, i hate when people check a function's arity. :P). should we close this?

[tj]

yeah might as well close for now I don't have super strong opinions on it, keeps the signature nice and clean :D