See https://github.com/cujojs/when/issues/403

gistfile1.js

// See https://github.com/cujojs/when/issues/403

// Generated by CoffeeScript 1.8.0
var When, arrayItems, catchCount, esprima, expand, file, fileTxt, files, fs, i, jspath, path, readFileP, _i, _j, _len;

fs = require('fs');

When = require('when');

When.node = require('when/node');

When.sequence = require('when/sequence');

readFileP = When.node.lift(fs.readFile);

path = require('path');

expand = require('glob-expand');

esprima = require('esprima');

jspath = '../node_modules/lodash';

arrayItems = [];

for (i = _i = 1; _i <= 1000; i = ++_i) {
  arrayItems.push((function(i) {
    return function() {
      return When(i);
    };
  })(i));
}

fileTxt = null;

files = expand({
  cwd: jspath,
  filter: 'isFile'
}, ['**/*.js']);

for (_j = 0, _len = files.length; _j < _len; _j++) {
  file = files[_j];
  fileTxt = fs.readFileSync(path.join(jspath, file), 'utf8');
  esprima.parse(fileTxt);
  console.log("test parsing file is ok `" + file + "`");
}

catchCount = 0;

When.iterate(function(i) {
  return i + 1;
}, function(i) {
  return !(i < arrayItems.length);
}, function(i) {
  var item;
  item = arrayItems[i];
  return When.iterate(function(j) {
    return j + 1;
  }, function(j) {
    return !(j < files.length);
  }, function(j) {
    var p;
    file = files[j];
    p = When.sequence([
      function() {
        return item().then(function(v) {
          return When(v).delay(1).then(function(v) {
            console.log("#" + v + " reading file with promise: `" + file + "`");
            return readFileP(path.join(jspath, file), 'utf8').then(function(res) {
              return fileTxt = res;
            });
          });
        });
      }, function() {
        return item().then(function(v) {
          return When(v).delay(1).then(function(v) {
            var ast, _k;
            console.log("#" + v + " parsing file: `" + file + "`");
            for (i = _k = 1; _k <= 10; i = ++_k) {
              ast = esprima.parse(fileTxt);
            }
            return console.log(fileTxt.slice(1, 101), ast.type);
          });
        });
      }
    ]);
    console.log('registering catch #', catchCount++);
    return p["catch"](function(err) {
      l.error("An error was caught:", err);
      return process.exit(1);
    });
  }, 0);
}, 0);