preventScroll-textarea.html (1983B)
1 <!doctype html> 2 <title>focus(options) - preventScroll on textarea element</title> 3 <link rel="author" href="https://mozilla.org" title="Mozilla"> 4 <link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez"> 5 <link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1634153"> 6 <script src=/resources/testharness.js></script> 7 <script src=/resources/testharnessreport.js></script> 8 <div style="height: 200vh"></div> 9 <textarea>ABCD</textarea> 10 <input value="EFGH"> 11 <button></button> 12 <div style="height: 200vh"></div> 13 <script> 14 promise_test(async function(t) { 15 await new Promise(resolve => window.addEventListener("load", resolve)); 16 let elements = document.querySelectorAll("textarea, input, button"); 17 assert_equals(elements.length, 3, `Precondition`); 18 for (let element of elements) { 19 let name = element.nodeName; 20 assert_equals(window.scrollY, 0, `${name}: Precondition`); 21 element.focus({ preventScroll: true }); 22 assert_equals(window.scrollY, 0, `${name}: Should not have scrolled`); 23 assert_equals(document.activeElement, element, `${name}: Should have been focused`); 24 25 // Wait a couple event loop turns because the original bug was triggered off 26 // an async event. 27 await new Promise(resolve => t.step_timeout(resolve, 0)); 28 await new Promise(resolve => t.step_timeout(resolve, 0)); 29 assert_equals(window.scrollY, 0, `${name}: Should not have scrolled after a couple event loop ticks`); 30 assert_equals(document.activeElement, element, `${name}: Should remain focused`); 31 32 // Also wait for rendering, just out of paranoia. 33 await new Promise(resolve => requestAnimationFrame(resolve)); 34 await new Promise(resolve => requestAnimationFrame(resolve)); 35 36 assert_equals(window.scrollY, 0, `${name}: Should not have scrolled after rendering`); 37 assert_equals(document.activeElement, element, `${name}: Should remain focused after rendering`); 38 } 39 }, "preventScroll: true on a textarea element"); 40 </script>