Fix throttle() bug

- now trailing invoke has additional parameter properly.

Author: minhyeong-kim

src/tricks.js

@@ -50,7 +50,7 @@
         delay = delay || 0;
 
         function debounced() {
-            args = arguments;
+            args = aps.call(arguments);
 
             window.clearTimeout(timer);
             timer = window.setTimeout(function() {
@@ -129,7 +129,12 @@
 
             base = base || stamp;
 
-            debounced();
+            // pass array directly because `debounce()`, `tick()` are already use
+            // `apply()` method to invoke developer's `fn` handler.
+            //
+            // also, this `debounced` line invoked every time for implements 
+            // `trailing` features.
+            debounced(args);
 
             if ((stamp - base) >= interval) {
                 tick(args);

test/tricks.test.js

@@ -81,6 +81,40 @@ describe('tricks', function() {
             expect(tui.util.debounce).toHaveBeenCalled();
         });
 
+        it('debounced method must invoke with additional parameter', function() {
+            var magazine = [1, 3, 6, 8, 9],
+                fireGun = reload(magazine),
+                fn;
+
+            spyOn(tui.util, 'timestamp').and.callFake(function() {
+                return fireGun();
+            });
+
+            var debounced = jasmine.createSpy('debounced');
+            spyOn(tui.util, 'debounce').and.returnValue(debounced);
+
+            fn = tui.util.throttle(spy, 7);
+
+            fn('hello');
+            fn('hello');
+            fn('hello');
+            fn('hello');
+            fn('hello');
+
+            expect(spy.calls.count()).toBe(2);
+            expect(tui.util.debounce).toHaveBeenCalled();
+
+            expect(debounced.calls.count()).toBe(4);
+            // debounce가 이미 콜백을 apply 처리하고 있는데, Mock을 했기 때문에
+            // args 를 그냥 넘겨준다 따라서 TC에서만은 각 debounce의 파라미터가 배열 형태임.
+            expect(debounced.calls.allArgs()).toEqual([
+                [['hello']],
+                [['hello']],
+                [['hello']],
+                [['hello']]
+            ]);
+        });
+
         it('reset can remove slugs related with throttling.', function() {
             var magazine = [1, 3, 6, 8, 9],
                 fireGun = reload(magazine),