reactjs
[Bug]: Browser back button not working as expected after scrolling down the page
Summary
After slowly scrolling all the way down a page like https://react.dev/learn/separating-events-from-effects, I have to hit the browser back button several times before I'm actually taken to the previous page in my history.
Page
https://react.dev/learn/separating-events-from-effects
Details
I've often noticed that once I've read to the bottom of a page in the React docs, I have to hit my browser's back button several times before I'm actually taken to the previous page in my browser history. I've noticed this at least on Android Chrome and macOS Firefox.
As I scroll down a page like https://react.dev/learn/separating-events-from-effects, certain elements seem to create "phantom" browser-history entries when they enter the viewport. Here is a video grab demonstrating what I mean:
https://github.com/user-attachments/assets/f67aba96-52f7-4f4c-a744-1122bdf3e91a
In this clip, at first there are no previous browser-history entries available to go back to (the back button is dimmed). However, once the "Extracting non-reactive logic out of Effects" heading comes into view, an entry is created. If I start at the top of the page and scroll all the way to the bottom (slowly), I have to hit the back button four times before the browser navigates to my previous page; the first three times, nothing appears to happen at all.
This may or may not be related to #8021 and/or #787.
I was able to reproduce the bug as well. Upon investigation, I found that the issue lies with the registerBundler in src/components/MDX/Sandpack/Preview.tsx:102. Commenting out that line prevents the history from growing.
