| <!DOCTYPE html> |
| <html class="reftest-wait foo"> |
| <title>View transitions: ensure :only-child is supported on view-transition-image-pair</title> |
| <link rel="help" href="https://drafts.csswg.org/css-view-transitions-1/"> |
| <link rel="author" href="mailto:khushalsagar@chromium.org"> |
| |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| |
| <style> |
| ::view-transition { |
| background-color: black; |
| } |
| html:only-child { |
| background-color: black; |
| } |
| :root:only-child { |
| background-color: black; |
| } |
| :only-child { |
| background-color: black; |
| } |
| .foo:only-child { |
| background-color: black; |
| } |
| |
| ::view-transition-image-pair(root):only-child { |
| background-color: red; |
| } |
| ::view-transition-image-pair(*):only-child { |
| color: red; |
| } |
| </style> |
| |
| <script> |
| promise_test(() => { |
| assert_implements(document.startViewTransition, "Missing document.startViewTransition"); |
| return new Promise(async (resolve, reject) => { |
| let transition = document.startViewTransition(); |
| transition.ready.then(() => { |
| let style = getComputedStyle(document.documentElement, "::view-transition-image-pair(root)"); |
| if (style.backgroundColor == "rgb(255, 0, 0)" && style.color == "rgb(255, 0, 0)") |
| resolve(); |
| else |
| reject(style.backgroundColor + " and " + style.color); |
| }); |
| }); |
| }, ":only-child should always match for ::view-transition-image-pair"); |
| </script> |
