experimental implementation: flow.exec

gistfile1.js

var flow = require('../index').flow;
var fs = require('fs');

var hogeFlow = flow(
  function (a, b) {
    var self = this;
    throw new Error('ERROR');
    setTimeout(function () {
      self.next('HELLO' + a + b);
    }, 0);
  }
);

flow.exec = function exec(fn) {
  var callback = arguments[arguments.length - 1];
  var args = Array.prototype.slice.call(arguments, 1, arguments.length - 1);
  flow(fn, function () {
    callback.apply(null, [this.err].concat(this.args));
  }).apply(null, args);
}

var myFlow = flow(
  function readFiles(file1, file2) {
    fs.readFile(file1, 'utf8', this.async());
    fs.readFile(file2, 'utf8', this.async());
    flow.exec(hogeFlow, 'a', 'b', this.async());
  },
  function concat(data1, data2, data3) {
    this.next(data1 + data2 + data3);
  },
  function end(data) {
    if (this.err) throw this.err;
    console.log(data);
    console.log('done');
    this.next();
  }
);

myFlow('file1', 'file2');