Add flush to debounced methods.

lodash.js

@@ -7904,10 +7904,10 @@
      * Creates a debounced function that delays invoking `func` until after `wait`
      * milliseconds have elapsed since the last time the debounced function was
      * invoked. The debounced function comes with a `cancel` method to cancel
-     * delayed invocations. Provide an options object to indicate that `func`
+     * delayed `func` invocations and a `flush` method to immediately invoke them.
-     * should be invoked on the leading and/or trailing edge of the `wait` timeout.
+     * Provide an options object to indicate that `func` should be invoked on the
-     * Subsequent calls to the debounced function return the result of the last
+     * leading and/or trailing edge of the `wait` timeout. Subsequent calls to the
-     * `func` invocation.
+     * debounced function return the result of the last `func` invocation.
      *
      * **Note:** If `leading` and `trailing` options are `true`, `func` is invoked
      * on the trailing edge of the timeout only if the the debounced function is
@@ -8020,6 +8020,14 @@
         }
       }
 
+      function flush() {
+        if ((timeoutId && trailingCall) || (maxTimeoutId && trailing)) {
+          result = func.apply(thisArg, args);
+        }
+        cancel();
+        return result;
+      }
+
       function maxDelayed() {
         complete(trailing, timeoutId);
       }
@@ -8066,6 +8074,7 @@
         return result;
       }
       debounced.cancel = cancel;
+      debounced.flush = flush;
       return debounced;
     }
 

test/test.js

@@ -18732,6 +18732,33 @@
         done();
       }
     });
+
+    QUnit.test('_.' + methodName + ' should support flushing delayed calls', function(assert) {
+      assert.expect(2);
+
+      var done = assert.async();
+
+      if (!(isRhino && isModularize)) {
+        var callCount = 0;
+
+        var funced = func(function() {
+          return ++callCount;
+        }, 32, { 'leading': false });
+
+        funced();
+        var actual = funced.flush();
+
+        setTimeout(function() {
+          assert.strictEqual(actual, 1);
+          assert.strictEqual(callCount, 1);
+          done();
+        }, 64);
+      }
+      else {
+        skipTest(assert, 2);
+        done();
+      }
+    });
   });
 
   /*--------------------------------------------------------------------------*/