rrweb
rrweb copied to clipboard
Published
20 hours ago •
rrweb-io
rrweb-io
[Bug]: Initial "fullSnapshot" does not include styles added via CSSStyleSheet / "adoptedStylesheets"
Preflight Checklist
- [X] I have searched the issue tracker for a bug report that matches the one I want to file, without success.
What package is this bug report for?
rrweb
Version
2.0.0-alpha.18
Expected Behavior
- The initial "fullSnapshot" frame includes styles which are synchronously added via Javascript
Actual Behavior
- The initial "fullSnapshot" frame does NOT include styles added via creation of a
new CSSStyleSheet();added to the DOM viadocument.adoptedStyleSheets
Steps to Reproduce
Issue:
The Initial "fullSnapshot" in a recording does not include styles added via CSSStyleSheet / "adoptedStylesheets".
Styles added via direct DOM manipulation (e.g. "elem.style.border = ...") and via document.createElement("<style>") "work" in the sense that the initial "fullSnapshot" includes those styles.
This is a bug because the un-styled frame is never painted by the browser, but the replay includes this unstyled initial "fullSnapshot."
To reproduce:
Copy this into an HTML file and then open it, and look at the DevTools console log (or download this gist):
<html>
<head>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/rrweb@latest/dist/style.css" />
<script type="module">
import { record } from 'https://cdn.jsdelivr.net/npm/[email protected]/+esm';
window.events = [];
record({
emit(event) {
// store the event in any way you like
window.events.push(event);
},
});
setTimeout(() => {
const initialFrame = window.events.find(e => e.type === 2);
const success = JSON.stringify(initialFrame).includes("lightgrey");
if (success) {
console.log("TEST PASSED: initial frame has our styles");
} else {
console.error("TEST FAILED: initial frame does not have our styles");
const eventIdx = window.events.findIndex(e => JSON.stringify(e).includes("lightgrey"))
console.log(`\t however; window.events[${eventIdx}] does have our styles`, window.events[eventIdx]);
}
}, 1500)
</script>
</head>
<body>
<div id="content">
<h1>test</h1>
<p>some text</p>
</div>
<script>
// three ways to add styles via JS to `#content` div
// the first two work, the third one fails
// ** method (1) **
// const elem = document.getElementById('content');
// elem.style.border = '1px solid black';
// elem.style.backgroundColor = 'lightgrey';
// ** method (2) **
// const s = document.createElement('style');
// const cssVars = `border: 1px solid black;\nbackground-color: lightgrey;`;
// s.type = 'text/css';
// s.innerText = `#content { ${cssVars} }`;
// document.head.appendChild(s);
// ** method (3) **
// this does not; causes unstyled initial "fullSnapshot" frame
let sheet = new CSSStyleSheet();
const cssVars = `border: 1px solid black;\nbackground-color: lightgrey;`;
sheet.insertRule(`#content { ${cssVars} }`);
document.adoptedStyleSheets = [...(document.adoptedStyleSheets ?? []), sheet];
</script>
</body>
</html>
Testcase Gist URL
No response
Additional Information
This is related to, but slightly different from, this issue: https://github.com/rrweb-io/rrweb/issues/1230
