P.coroutine and _.curry issue

p-co-and-lodash-curry.js

function asyncSum(x, y) {
  return new Promise(resolve => setInterval(
    () => resolve(x + y)), 10
  )
}

function asyncSquare(x, y) {
  return new Promise(resolve => setInterval(
    () => resolve(x * y)), 10
  )
}


// WORKS
test('can I haz vanilla curry?', async t => {
  const _ = require('_')

  const asyncSumAndSquare = function asyncSumAndSquare(x, y) {
    return asyncSum(x, y).then(sum => asyncSquare(sum, sum))
  }

  const parialAsyncSumAndSquare = _.curry(asyncSumAndSquare)
  const result = await parialAsyncSumAndSquare(2)(2)

  t.is(result, 16)
})


// FAILS, since P.coroutine messes up with parameters, it returns a function that accepts ONE argument
// co behaves in the same way, tested with lodash 3 and 4
test('bad curry', async t => {
  const _ = require('_')
  const P = require('bluebird')

  const asyncSumAndSquare = P.coroutine(function *asyncSumAndSquare(x, y) {
    const sum = yield asyncSum(x, y)
    const square = yield asyncSquare(sum, sum)
    return square
  })

  // curry is unable to curry P.coroutine
  const parialAsyncSumAndSquare = _.curry(asyncSumAndSquare)

  const result = await parialAsyncSumAndSquare(2)(2)
  t.is(result, 16)
})

// WORKS
test('manual curry', async t => {
  const P = require('bluebird')

  const asyncSumAndSquare = P.coroutine(function *asyncSumAndSquare(x, y) {
    const sum = yield asyncSum(x, y)
    const square = yield asyncSquare(sum, sum)
    return square
  })

  const partialAsyncSumAndSquare = x => y => asyncSumAndSquare(x, y)

  const result = await partialAsyncSumAndSquare(2)(2)
  t.is(result, 16)
})