Add _.throttle unit test for recursive calls.

Former-commit-id: 7208516b56905c83df73aef6b02cee0101602349

doc/README.md

@@ -2221,7 +2221,7 @@ _.template('<%= data.hasWith %>', { 'hasWith': 'no' }, { 'variable': 'data' });
 ### <a id="_throttlefunc-wait"></a>`_.throttle(func, wait)`
 <a href="#_throttlefunc-wait">#</a> [&#x24C8;](https://github.com/bestiejs/lodash/blob/v0.3.1/lodash.js#L2174 "View in source") [&#x24C9;][1]
 
-Creates a new function that, when executed, will only call the `func` function at most once per every `wait` milliseconds. If the throttled function is invoked more than once, `func` will also be called on the trailing edge of the `wait` timeout. Subsequent calls to the throttled function will return the result of the last `func` call.
+Creates a new function that, when executed, will only call the `func` function at most once per every `wait` milliseconds. If the throttled function is invoked more than once during the `wait` timeout, `func` will also be called on the trailing edge of the timeout. Subsequent calls to the throttled function will return the result of the last `func` call.
 
 #### Arguments
 1. `func` *(Function)*: The function to throttle.

lodash.js

@@ -2155,10 +2155,10 @@
 
   /**
    * Creates a new function that, when executed, will only call the `func`
-   * function at most once per every `wait` milliseconds. If the throttled function
-   * is invoked more than once, `func` will also be called on the trailing edge
-   * of the `wait` timeout. Subsequent calls to the throttled function will
-   * return the result of the last `func` call.
+   * function at most once per every `wait` milliseconds. If the throttled
+   * function is invoked more than once during the `wait` timeout, `func` will
+   * also be called on the trailing edge of the timeout. Subsequent calls to the
+   * throttled function will return the result of the last `func` call.
    *
    * @static
    * @memberOf _

test/test.js

@@ -642,6 +642,23 @@
       }
       ok(counter > 1);
     });
+
+    asyncTest('supports recursive calls', function() {
+      var counter = 0;
+      var throttled = _.throttle(function() {
+        counter++;
+        if (counter < 4) {
+          throttled();
+        }
+      }, 100);
+
+      setTimeout(function() {
+        ok(counter > 1);
+        QUnit.start();
+      }, 220);
+
+      throttled();
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -790,6 +807,7 @@
   /*--------------------------------------------------------------------------*/
 
   // explicitly call `QUnit.start()` for Narwhal, Rhino, and RingoJS
-  QUnit.start();
-
+  if (!window.document) {
+    QUnit.start();
+  }
 }(typeof global == 'object' && global || this));