Bug: React Refresh with HMR regresses changes if a dependent module changes and then the depending module changes

[aaronjensen]

If I have a module tree like this:

App imports Guide

Guide imports Bubble

Bubble exports a string const

Guide uses the string in a React compnoent

If I change Bubble, then HMR works and I see the new Bubble
If I change Guide AFTER that, then the previous version of Bubble is used, which regresses the first HMR.

Here's a video:

Screen Recording 2020-11-16 at 9.05.19 PM.mp4.zip

Here's a repro:

https://github.com/aaronjensen/snowpack-hmr-repro

I couldn't find any existing discussions that had this same issue...

[aaronjensen]

I don't know for certain, but it's possible this is related: facebook/react#17281

[aaronjensen]

I just tested the same scenario on Next.js and it didn't reproduce, so it seems unlikely to be an issue with Fast Refresh itself. @FredKSchott any ideas?

[aaronjensen]

Okay, it looks like this regressed in 2.9.0. The bad commit is:

c5490fd

@Akimyou do you know what would cause this? I'll dig into the change a little and see if I can find the cause.

[aaronjensen]

This fixes it, though I do not understand the original change fully, so I do not know if it is correct: #1642

[aaronjensen]

This regressed again. It's broken in Snowpack 3.3.7.