added unit testing, and started implementing unit tests...phew

node_modules/async/internal/eachOfLimit.js

@@ -0,0 +1,74 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+exports.default = _eachOfLimit;
+
+var _noop = require('lodash/noop');
+
+var _noop2 = _interopRequireDefault(_noop);
+
+var _once = require('./once');
+
+var _once2 = _interopRequireDefault(_once);
+
+var _iterator = require('./iterator');
+
+var _iterator2 = _interopRequireDefault(_iterator);
+
+var _onlyOnce = require('./onlyOnce');
+
+var _onlyOnce2 = _interopRequireDefault(_onlyOnce);
+
+var _breakLoop = require('./breakLoop');
+
+var _breakLoop2 = _interopRequireDefault(_breakLoop);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+function _eachOfLimit(limit) {
+    return function (obj, iteratee, callback) {
+        callback = (0, _once2.default)(callback || _noop2.default);
+        if (limit <= 0 || !obj) {
+            return callback(null);
+        }
+        var nextElem = (0, _iterator2.default)(obj);
+        var done = false;
+        var running = 0;
+        var looping = false;
+
+        function iterateeCallback(err, value) {
+            running -= 1;
+            if (err) {
+                done = true;
+                callback(err);
+            } else if (value === _breakLoop2.default || done && running <= 0) {
+                done = true;
+                return callback(null);
+            } else if (!looping) {
+                replenish();
+            }
+        }
+
+        function replenish() {
+            looping = true;
+            while (running < limit && !done) {
+                var elem = nextElem();
+                if (elem === null) {
+                    done = true;
+                    if (running <= 0) {
+                        callback(null);
+                    }
+                    return;
+                }
+                running += 1;
+                iteratee(elem.value, elem.key, (0, _onlyOnce2.default)(iterateeCallback));
+            }
+            looping = false;
+        }
+
+        replenish();
+    };
+}
+module.exports = exports['default'];