Preact-router and setState callback does not play nice

"preact": "^10.4.4",
"preact-router": "^3.2.1",

Reproduction

Here is a minimal code to reproduce this issue. https://codesandbox.io/s/compassionate-rgb-kl85q?file=/src/index.js

I am setting state with this.setState and reading it immediately in setState callback (second argument). See line # 13

Steps to reproduce

• open console tab
• find console.log output from line # 14

Expected Behavior

state should be { initial: true, handleRoute: true }

Actual Behavior

state is { initial: true }

I can set state and read it immediately in setState callback in componentDidMount and other places but not in preact-router’s onChange callback.

[jamesb3ll]

Thanks @JoviDeCroock for replying on Twitter 😃 From what I understood adding c.state = c._nextState; just before here: https://github.com/preactjs/preact/blob/0f8c55c6cfad8d5cc3aec6785c1f6940998b4782/src/diff/index.js#L251 This will render the following to the console (with the code in prev. comment):

rendered: true
callback { initial: true, rendered: true }
rendered: true
mounted { initial: true, rendered: true, didMount: true }

So I think this fixes the issue 🤦 🎉haha Thanks Jovi! Although it’s still not aligned with React? Is that okay?

[JoviDeCroock]

Putting it behind render makes the intent clear of being done inside of render, so I’m all for it