Bump to v4.0.0.

includes.js

@@ -0,0 +1,51 @@
+import baseIndexOf from './internal/baseIndexOf';
+import isArrayLike from './isArrayLike';
+import isString from './isString';
+import toInteger from './toInteger';
+import values from './values';
+
+/* Built-in method references for those with the same name as other `lodash` methods. */
+var nativeMax = Math.max;
+
+/**
+ * Checks if `value` is in `collection`. If `collection` is a string it's checked
+ * for a substring of `value`, otherwise [`SameValueZero`](http://ecma-international.org/ecma-262/6.0/#sec-samevaluezero)
+ * is used for equality comparisons. If `fromIndex` is negative, it's used as
+ * the offset from the end of `collection`.
+ *
+ * @static
+ * @memberOf _
+ * @category Collection
+ * @param {Array|Object|string} collection The collection to search.
+ * @param {*} value The value to search for.
+ * @param {number} [fromIndex=0] The index to search from.
+ * @param- {Object} [guard] Enables use as an iteratee for functions like `_.reduce`.
+ * @returns {boolean} Returns `true` if `value` is found, else `false`.
+ * @example
+ *
+ * _.includes([1, 2, 3], 1);
+ * // => true
+ *
+ * _.includes([1, 2, 3], 1, 2);
+ * // => false
+ *
+ * _.includes({ 'user': 'fred', 'age': 40 }, 'fred');
+ * // => true
+ *
+ * _.includes('pebbles', 'eb');
+ * // => true
+ */
+function includes(collection, value, fromIndex, guard) {
+  collection = isArrayLike(collection) ? collection : values(collection);
+  fromIndex = (fromIndex && !guard) ? toInteger(fromIndex) : 0;
+
+  var length = collection.length;
+  if (fromIndex < 0) {
+    fromIndex = nativeMax(length + fromIndex, 0);
+  }
+  return isString(collection)
+    ? (fromIndex <= length && collection.indexOf(value, fromIndex) > -1)
+    : (!!length && baseIndexOf(collection, value, fromIndex) > -1);
+}
+
+export default includes;