| <!DOCTYPE html> |
| <meta charset="utf-8"> |
| <title>window.getComputedStyle() basics</title> |
| <link rel="help" href="https://drafts.csswg.org/cssom/#dom-window-getcomputedstyle"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| |
| <div id="div">Test</div> |
| |
| <script> |
| "use strict"; |
| |
| const div = document.getElementById("div"); |
| const computed = window.getComputedStyle(div); |
| |
| test(() => { |
| assert_equals(div.style.cssText, "", "Specified CSS text is empty string."); |
| assert_equals(computed.cssText, "", "Computed CSS text is empty string."); |
| assert_equals(div.style.backgroundColor, "", "Specified property value is empty string"); |
| assert_equals(computed.backgroundColor, "rgba(0, 0, 0, 0)", "Computed property value is resolved initial value."); |
| assert_not_equals(computed, window.getComputedStyle(div), "getComputedStyle() creates new instance each time."); |
| }, "Sanity check"); |
| |
| test(() => { |
| div.style.cssText = "color: green;"; |
| assert_equals( |
| div.style.cssText, |
| "color: green;", |
| "CSS text of specified value is not empty." |
| ); |
| assert_equals( |
| window.getComputedStyle(div).cssText, |
| "", |
| "CSS text of computed value is always empty string." |
| ); |
| }, "cssText"); |
| |
| test(() => { |
| assert_throws_dom( |
| "NoModificationAllowedError", |
| () => { |
| computed.setProperty("color", "red"); |
| }, |
| "Modifying computed value is not allowed." |
| ); |
| }, "setProperty"); |
| |
| test(() => { |
| assert_throws_dom( |
| "NoModificationAllowedError", |
| () => { |
| computed.removeProperty("color"); |
| }, |
| "Modifying property is not allowed." |
| ); |
| }, "removeProperty"); |
| </script> |
