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

node_modules/async/mapValuesLimit.js

@@ -0,0 +1,61 @@
+'use strict';
+
+Object.defineProperty(exports, "__esModule", {
+    value: true
+});
+exports.default = mapValuesLimit;
+
+var _eachOfLimit = require('./eachOfLimit');
+
+var _eachOfLimit2 = _interopRequireDefault(_eachOfLimit);
+
+var _noop = require('lodash/noop');
+
+var _noop2 = _interopRequireDefault(_noop);
+
+var _once = require('./internal/once');
+
+var _once2 = _interopRequireDefault(_once);
+
+var _wrapAsync = require('./internal/wrapAsync');
+
+var _wrapAsync2 = _interopRequireDefault(_wrapAsync);
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+
+/**
+ * The same as [`mapValues`]{@link module:Collections.mapValues} but runs a maximum of `limit` async operations at a
+ * time.
+ *
+ * @name mapValuesLimit
+ * @static
+ * @memberOf module:Collections
+ * @method
+ * @see [async.mapValues]{@link module:Collections.mapValues}
+ * @category Collection
+ * @param {Object} obj - A collection to iterate over.
+ * @param {number} limit - The maximum number of async operations at a time.
+ * @param {AsyncFunction} iteratee - A function to apply to each value and key
+ * in `coll`.
+ * The iteratee should complete with the transformed value as its result.
+ * Invoked with (value, key, callback).
+ * @param {Function} [callback] - A callback which is called when all `iteratee`
+ * functions have finished, or an error occurs. `result` is a new object consisting
+ * of each key from `obj`, with each transformed value on the right-hand side.
+ * Invoked with (err, result).
+ */
+function mapValuesLimit(obj, limit, iteratee, callback) {
+    callback = (0, _once2.default)(callback || _noop2.default);
+    var newObj = {};
+    var _iteratee = (0, _wrapAsync2.default)(iteratee);
+    (0, _eachOfLimit2.default)(obj, limit, function (val, key, next) {
+        _iteratee(val, key, function (err, result) {
+            if (err) return next(err);
+            newObj[key] = result;
+            next();
+        });
+    }, function (err) {
+        callback(err, newObj);
+    });
+}
+module.exports = exports['default'];