Bug: Cannot use 'in' operator to search for 'data' in null

[kweng-stripe]

Issue with react-dom, consistently with Chrome 87 Cannot use 'in' operator to search for 'data' in null

In getDataFromCustomEvent: if (typeof detail === 'object' && 'data' in detail) {

The problem is that typeof null is also 'object'

React version: 17.0.2

Steps To Reproduce

Unfortunately I cannot reproduce, but what appears to be a headless chrome87 scanner fairly consistently reproduces the issue.

[eps1lon]

Unfortunately I cannot reproduce, but what appears to be a headless chrome87 scanner fairly consistently reproduces the issue.

Could you create a cloneable repository that has the minimal amount of code to reproduce this issue? It's hard otherwise to understand where assumptions were incorrect.

[kweng-stripe]

I'll try to gather minimal amount of code to repro, but in the meantime it's repro-able on

• https://marketplace.stripe.com
• https://connect.stripe.com/login
• https://dashboard.stripe.com/login from Mac OS X 10.15.7 and Chrome 87.0.4280