Bump to v4.0.0.

differenceBy.js

@@ -0,0 +1,39 @@
+import baseDifference from './internal/baseDifference';
+import baseFlatten from './internal/baseFlatten';
+import baseIteratee from './internal/baseIteratee';
+import isArrayLikeObject from './isArrayLikeObject';
+import last from './last';
+import rest from './rest';
+
+/**
+ * This method is like `_.difference` except that it accepts `iteratee` which
+ * is invoked for each element of `array` and `values` to generate the criterion
+ * by which uniqueness is computed. The iteratee is invoked with one argument: (value).
+ *
+ * @static
+ * @memberOf _
+ * @category Array
+ * @param {Array} array The array to inspect.
+ * @param {...Array} [values] The values to exclude.
+ * @param {Function|Object|string} [iteratee=_.identity] The iteratee invoked per element.
+ * @returns {Array} Returns the new array of filtered values.
+ * @example
+ *
+ * _.differenceBy([3.1, 2.2, 1.3], [4.4, 2.5], Math.floor);
+ * // => [3.1, 1.3]
+ *
+ * // using the `_.property` iteratee shorthand
+ * _.differenceBy([{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }], 'x');
+ * // => [{ 'x': 2 }]
+ */
+var differenceBy = rest(function(array, values) {
+  var iteratee = last(values);
+  if (isArrayLikeObject(iteratee)) {
+    iteratee = undefined;
+  }
+  return isArrayLikeObject(array)
+    ? baseDifference(array, baseFlatten(values, false, true), baseIteratee(iteratee))
+    : [];
+});
+
+export default differenceBy;