Bump to v4.0.0.

xorBy.js

@@ -0,0 +1,35 @@
+define(['./internal/arrayFilter', './internal/baseIteratee', './internal/baseXor', './isArrayLikeObject', './last', './rest'], function(arrayFilter, baseIteratee, baseXor, isArrayLikeObject, last, rest) {
+
+  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
+  var undefined;
+
+  /**
+   * This method is like `_.xor` except that it accepts `iteratee` which is
+   * invoked for each element of each `arrays` to generate the criterion by which
+   * uniqueness is computed. The iteratee is invoked with one argument: (value).
+   *
+   * @static
+   * @memberOf _
+   * @category Array
+   * @param {...Array} [arrays] The arrays to inspect.
+   * @param {Function|Object|string} [iteratee=_.identity] The iteratee invoked per element.
+   * @returns {Array} Returns the new array of values.
+   * @example
+   *
+   * _.xorBy([2.1, 1.2], [4.3, 2.4], Math.floor);
+   * // => [1.2, 4.3]
+   *
+   * // using the `_.property` iteratee shorthand
+   * _.xorBy([{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }], 'x');
+   * // => [{ 'x': 2 }]
+   */
+  var xorBy = rest(function(arrays) {
+    var iteratee = last(arrays);
+    if (isArrayLikeObject(iteratee)) {
+      iteratee = undefined;
+    }
+    return baseXor(arrayFilter(arrays, isArrayLikeObject), baseIteratee(iteratee));
+  });
+
+  return xorBy;
+});