Add thisArg to _.tap.

lodash.js

@@ -6842,16 +6842,17 @@
     }
 
     /**
-     * Invokes `interceptor` with the `value` as the first argument and then
-     * returns `value`. The purpose of this method is to "tap into" a method
-     * chain in order to perform operations on intermediate results within
-     * the chain.
+     * This method invokes `interceptor` and returns `value`. The interceptor is
+     * bound to `thisArg` and invoked with one argument; (value). The purpose of
+     * this method is to "tap into" a method chain in order to perform operations
+     * on intermediate results within the chain.
      *
      * @static
      * @memberOf _
      * @category Chaining
      * @param {*} value The value to provide to `interceptor`.
      * @param {Function} interceptor The function to invoke.
+     * @param {*} [thisArg] The `this` binding of `interceptor`.
      * @returns {*} Returns `value`.
      * @example
      *
@@ -6861,8 +6862,8 @@
      *  .value();
      * // => [3, 2, 1]
      */
-    function tap(value, interceptor) {
-      interceptor(value);
+    function tap(value, interceptor, thisArg) {
+      interceptor.call(thisArg, value);
       return value;
     }