componentDidUpdate affects component state

[zjhch123]

• Check if updating to the latest Preact version resolves the issue

Describe the bug

componentDidUpdate affects component state

To Reproduce

https://codesandbox.io/s/crimson-worker-1koisq?file=/src/index.js

1. Open Console, it shows { count: null, isLoading: false }
   

2. Comment the line of componentDidUpdate, refresh demo page, in console, it shows { count: { value: 10 }, isLoading: false }
   

Expected behavior

Whether or not there is a componentDidUpdate event, the console should be { count: { value: 10 }, isLoading: false }

[JoviDeCroock]

Just took a quick look at the issue and it looks like the following is happening:

• componentDidMount gets invoked and initiates a render.
• we push a componentDidUpdate to the _renderCallbacks
• componentDidMount gets invoked and updates state
• the above setState call pushes to the _renderCallbacks queue
• render completes and the renderCallbacks get consumed before the next render is initiated making the setState callback called with a stale state as that one completes on the next invocation

[zjhch123]

Thank you @JoviDeCroock for your quick action!