| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>CSS Properties and Values API: optional initial-value descriptor</title> |
| <link rel="help" href="https://drafts.css-houdini.org/css-properties-values-api/#initial-value-descriptor"> |
| <link rel="help" href="https://github.com/w3c/csswg-drafts/issues/9078"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <style> |
| @property --registered { |
| syntax: '*'; |
| initial-value: ; |
| inherits: false; |
| } |
| #target { |
| --test-bg: var(--registered) green; |
| --test-fallback: var(--registered, red); |
| background-color: var(--test-bg, var(--test-fallback)); |
| } |
| </style> |
| <div id="target"></div> |
| <script> |
| test(function() { |
| const target = document.getElementById('target'); |
| const style = getComputedStyle(target); |
| |
| // When initial-value is omitted (empty space), the property should be registered |
| // with a space character as the initial value, making var(--registered) green |
| // evaluate to " green" which is a valid color value. |
| assert_equals(style.backgroundColor, 'rgb(0, 128, 0)', |
| 'background-color should be green when @property has empty initial-value'); |
| }, '@property with empty initial-value should use space character'); |
| </script> |
