unmountComponentAtNode doesn't unbind in-flight listeners, throws opaque error.

[lutherism]

Our React app was triggering the following error during navigation events:

Uncaught TypeError: Cannot read property 'firstChild' of undefined

The error was occurring in the function findComponentRoot, when it failed to find a component for an event callback.

In our app, this was happening when we would navigate during a blur event, and call unmountComponentAtNode on the rendering, in order to refresh the page. The docs for unmountComponentAtNode say

Remove a mounted React component from the DOM and clean up its event handlers and state

However, this does not seem to be the case. After we refresh the page with unmountComponentAtNode, there were other React-bound callbacks still in React's queue for that event. Leading to the error.

The docs and intuition seem to imply unmountComponentAtNode should clear these callbacks, since it knows the components will no longer exist to handle them.

[lencioni]

Is this perhaps a duplicate of #3298 and #2605?

[lutherism]

P

On Thu, Nov 12, 2015 at 10:04 AM Joe Lencioni notifications@github.com
wrote:

Is this perhaps a duplicate of #3298
#3298 and #2605
#2605?

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#4892 (comment).

[aweary]

Since there's no repro provided and there's been no activity for almost 2 years, I'm going to close this out. If this is still an issue with the latest version of React, please provide an example reproduction the issue so we can verify.

Thanks!