Migration bot

[tj]

Will implement this sometime unless someone wants to have some fun before me!

• fetch list of middleware etc from npm
• transform gen functions to async functions
• transform yields to awaits
• warn on use of co-isms (yield {}, yield [], etc)
• send pull-request for 2.x support

This doesn't need to really perform the PRs any time soon, but ideally we're ready for it when the time comes.

Related: #621

[haoxins]

transform yields to awaits

So, the recommended way for koa@2's middlewares is async/await(babel compiled for now), not use Promise directly ?

[dead-horse]

So, the recommended way for koa@2's middlewares is async/await(babel compiled for now), not use Promise directly ?

definitely.

[tj]

@coderhaoxin yea I think it's pointless to convert everything to promises, the yield -> async is almost a 1:1 change, promises are a little more complicated that way, and everyone will just be doing it all over again otherwise. I'm not suggesting babel here either though, just that we have something available for when Node gets async/await

[tejasmanohar]

So, the recommended way for koa@2's middlewares is async/await(babel compiled for now), not use Promise directly ?

+1. Either use Babel compiled (and still keep it on next dist-tag, not latest) or just wait but converting to the raw Promise-based API is not worth the effort since it's regression (IMO).

[SupaJoon]

I'd be happy to work on these things but I may need some guidance!

[tejasmanohar]

@aquascaper just ask whenever you have questions / need help :)

@tj Were you planning to run this bot on all koa 1.x middleware you can find in NPM or just the "official" ones (koajs/* repos)? I think it'd be fair to run them on ones we don't maintain as well since most of the "koa" related packages on NPM are middleware (since there's not much else I can think of that you can write for Koa haha).

[tj]

yea probably everything, could test drive on a few of the koajs/* ones first

[tejasmanohar]

👍 fair

[jonathanong]

If anyone wants to get started on this, I will make an empty repo in this org and add you to the team.

[Tankenstein]

I'm interested in doing this, need a couple days before i can start though.

[magicdawn]

warn on use of co-isms (yield {}, yield [], etc)

how about warn this in co.
cause foo = async function(){ } & foo = co.wrap(function*(){ }) are alomost same. but you can yield {}, yield [], yield thunk, and await can not.

[sibelius]

@tj consider using a codemod to transform javascript code using https://github.com/facebook/jscodeshift

Take a look at this: https://medium.com/@cpojer/effective-javascript-codemods-5a6686bb46fb#.vh2b6nqse

[shime]

@jonathanong I would love to start on this, what's the next step?

[jonathanong]

@shime start from scratch? i'm not sure anyone has started on this yet

[shime]

@jonathanong yup, sent you an email.

[hedgerh]

@shime @jonathanong let me know if i can do anything to help. jscodeshift, linked above by @sibelius, looks like it could be pretty handy for the transforms. https://github.com/facebook/jscodeshift

[shime]

@hedgerh sure, yeah that's a good idea. feel free to submit PRs to related middleware, I haven't submitted any yet.

[jonathanong]

I don't think we need this anymore :)