Bug: React DevTools 'Why did this component render?' incorrectly reports 'The parent component rendered'

[bgirard]

React Devtools shows why a component has re-render but sometimes it says 'The parent component rendered' when it just doesn't know. Ideally we would split out these two scenario, otherwise the string should highlight the uncertainty. Me and another Jimmy both went debugging the wrong thing and I lost time assuming the message was correct.

React version: React DevTools 4.8.2

Steps To Reproduce

I believe this bug happens when there's a context changing but I'm not positive.

[bpernick]

@bgirard looks like you're right; 'The parent component rendered' is the default when no changes are detected. I thought for now we could change it to 'Not verified. Likely that parent component rendered.' I think that makes it clear that it's a default; what do you think?

[bpernick]

It appears that the code handles context changes -- or thinks it does; I might submit a pr with the wording change right now and then poke around to see if I can figure out what broke it for you specifically

[bgirard]

Yea, any wording change for now would be great. If you can't find the root cause tell me know and I'll dig a bit more in my project to reduce it. But I'm fairly sure it was a useContext(...) that changed.

[kambleaa007]

should we close this, as @bpernick commited the fix for it?

[stale]

This issue has been automatically marked as stale. If this issue is still affecting you, please leave any comment (for example, "bump"), and we'll keep it open. We are sorry that we haven't been able to prioritize it yet. If you have any new additional information, please include it with your comment!

[penx]

the PR with the fix isn't merged yet and I'm seeing this issue today - I have:

const MyComponentMemo = React.memo(MyComponent)
MyComponentMemo.displayName = 'MyComponentMemo'

In dev tools (4.13.5-0ae5290b54) I can see that MyComponentMemo does not render, but MyComponent does render. The reason given is "The parent component rendered".

[Undistraction]

Still seeing the same thing in Version 4.21.0 (10/31/2021). Incorrect reporting of 'The parent component rendered' when it didn't. Looks like PR is still open.

[Lxylona]

Still seeing the same thing in Version 4.24.3 (4/21/2022). Incorrect reporting of 'The parent component rendered' when it didn't.

[eps1lon]

It would help a lot if someone could provide a minimal reproduction. In a large codebase start removing code until you can no longer reproduce the problem. Either share this reproduciton via https://react.new or a cloneable GitHub repository.

A context change has it's own message so it's likely not the cause of this issue: https://codesandbox.io/s/context-change-why-did-this-render-message-9rwf8i
Tested with DevTools version: 4.24.3-46a98cff2