1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
|
<!doctype html>
<meta charset=utf-8>
<title>Observer notifications when updating styles</title>
<link rel="help" href="https://drafts.csswg.org/cssom/#dom-cssstyledeclaration-setproperty">
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<body>
<script>
"use strict";
promise_test(async () => {
let called = 0;
const el = document.createElement("div");
document.body.appendChild(el);
const m = new MutationObserver(() => {
called++;
});
m.observe(el, { attributes: true });
el.style.height = "100px";
await Promise.resolve();
assert_equals(called, 1, "times callback called");
el.style.height = "100px";
await Promise.resolve();
assert_equals(called, 1, "times callback called");
}, "Updating style property with the same value does not trigger an observation callback");
promise_test(async () => {
let called = 0;
const el = document.createElement("div");
document.body.appendChild(el);
const m = new MutationObserver(() => {
called++;
});
m.observe(el, { attributes: true });
el.style.cssText = "height:100px";
await Promise.resolve();
assert_equals(called, 1, "times callback called");
el.style.cssText = "height:100px";
await Promise.resolve();
assert_equals(called, 2, "times callback called");
}, "Updating cssText triggers an observation callback even if the value is the same");
</script>
|
