Async auto pass in data from dependency

[mlovrovich]

It would be nice if there was a way to pass in results from a dependency directly into the function.
So instead of doing this:

async.auto({
    a: testFunction,
    b: ['a', function(callback, results){
        testFunction2(results.a, callback);
    }]
})

We could do something like,

async.auto({
    a: testFunction,
    b: ['a', async.apply(testFunction2, <resultsOfA>)]
})

[aearly]

#608 is a proposal for a different flavor of auto. I dont really like it because it relies on Function.toString() and won't play nice with minifiers.

I've also played around with code that builds the auto object from a list of steps, e.g.

[
  {
    task: function taskName(arg1, arg2, cb) {...},
    dependencies: ["arg1", "arg2"]
  },
  {
    task: function arg1 (cb) { cb(null, foo); }
  }
  //...
]

I've also played around with a couple higher-order functions that manipulate the argument order (from my experimental acomb library):

async.auto({
  taskName: ["arg1", "arg2", acomb.flip(acomb.spreadArgs(function (arg1, arg2, cb) {
    //...
  }, "arg1", "arg2")]
})

The main problem is you can't bind functions to future values, because they don't exist yet. Also, you always seem to have to explicitly specify the dependencies as strings. But one thing you can do is use function combinators that manipulate the arguments so that functions fit better into auto. It's a balance between usability and practicality and what is actually possible.