Memory leaks on page refresh

[aiyer07]

🐛 Bug Report

When refreshing a page that is using useSpring or Spring renderprop I'm noticing a memory leak

To Reproduce

1. Go to https://codesandbox.io/s/cocky-smoke-v6x9y for a simple count up example
2. Open browser incognito and open memory tab. Using heap timeline and snapshots, notice the memory steadily increases even after forcing garbage collection
3. Comment out Spring and there is no memory increase

Expected behavior

Expected memory to be garbage collected on refresh

Environment

Although I am running react-spring 9 i have noticed the same issue on the latest react-spring

• react-spring v9.0.0-beta.34
• react v16.13.1 (latest)
• next v9.4.4 (latest)

[aleclarson]

Please try v9.0.0-rc.3 #985 👍

[aiyer07]

Please try v9.0.0-rc.3 #985 👍

I updated the codesandbox to be v9.0.0-rc.3. Same issue. Just for the sake of visualizing, here's a heap allocation timeline while I refresh the app:

[aleclarson]

You can reproduce outside of CodeSandbox?

[aiyer07]

@aleclarson Yes I can. I am actually doing something very similar (a simple count up animation) in a next.js app.

Simply creating a spring using useSpring causes the leak in my components. Specifically seems to be a problem on page refresh

[aleclarson]

Ah, I looked over the detail that you're using NextJS. See here: #778

[aiyer07]

@aleclarson Thanks for that link I'm following that thread now. One thing that might be worth noting is that the codesandbox is not actually using ssr/nextjs, although i did discover the issue initially in a next app.