| <!DOCTYPE html> |
| <title>CSS Transitions Test: No transition if @starting-style display value is none</title> |
| <link rel="help" href="https://drafts.csswg.org/css-transitions-2/#defining-before-change-style-the-starting-style-rule"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="/css/css-transitions/support/helper.js"></script> |
| <div id="target"></div> |
| <style> |
| #target { |
| transition-property: background-color; |
| transition-duration: 100s; |
| transition-timing-function: steps(2, start); |
| background-color: green; |
| } |
| @starting-style { |
| #target { |
| display: none; |
| background-color: red; |
| } |
| } |
| </style> |
| <script> |
| setup(() => { |
| assert_true(supportsStartingStyle(), "Prerequisite: @starting-style parses"); |
| }); |
| |
| promise_test(async t => { |
| await waitForAnimationFrames(2); |
| assert_equals(getComputedStyle(target).backgroundColor, "rgb(0, 128, 0)", |
| "No transition of background-color when @starting-style display is 'none'"); |
| }, "@starting-style with display:none"); |
| </script> |
