|  | <!doctype html> | 
|  | <html> | 
|  | <head> | 
|  | <meta charset=utf-8> | 
|  | <title>CSS Transitions Test: Removing transition and changing width applies change immediately</title> | 
|  | <meta name="assert" content="When a transition is removed and a width is changed after a previous transition completes, the change is immediate."> | 
|  | <link rel="help" href="https://drafts.csswg.org/css-transitions/#starting"> | 
|  |  | 
|  | <script src="/resources/testharness.js"></script> | 
|  | <script src="/resources/testharnessreport.js"></script> | 
|  | <script src="./support/helper.js"></script> | 
|  |  | 
|  | </head> | 
|  | <body> | 
|  | <div id="log"></div> | 
|  |  | 
|  | <script> | 
|  | promise_test(async t => { | 
|  | const div = addDiv(t, { | 
|  | style: 'transition: width 0.02s; width: 0px;' | 
|  | }); | 
|  |  | 
|  | // Flush initial state | 
|  | getComputedStyle(div).width; | 
|  | div.style.width = '100px'; | 
|  |  | 
|  | // Wait for transition to complete | 
|  | await waitForTransitionEnd(div); | 
|  |  | 
|  | // Verify the width after first transition | 
|  | const afterFirst = getComputedStyle(div).width; | 
|  | assert_equals(afterFirst, '100px', 'width should be 100px after first transition'); | 
|  |  | 
|  | // Set width back to 0 and remove transition | 
|  | div.style.width = '0px'; | 
|  | div.style.transition = ''; | 
|  |  | 
|  | // Force layout update to ensure style computation | 
|  | const afterSecond = getComputedStyle(div).width; | 
|  | // Check width is immediately updated | 
|  | assert_equals( | 
|  | afterSecond, | 
|  | '0px', | 
|  | 'width should reset to 0 immediately' | 
|  | ); | 
|  |  | 
|  | }, 'Removing transition and changing width applies change immediately'); | 
|  | </script> | 
|  |  | 
|  | </body> | 
|  | </html> |