Can't catch thrown 'FLOW_CANCELED' anywhere

[DMS40]

Intended outcome:

This issue came from here

When flow function's cancel() fired, Can't catch thrown 'FLOW_CANCELED' anywhere

Actual outcome:

Can catch the flow function's cancel() fired, for don't want to show throw error message

This also interferes with the integrated test. like for react-testing-library

How to reproduce the issue:

https://codesandbox.io/s/magical-hugle-qc0d1?file=/src/App.js

Versions
mobx : 6.1.5
mobx-react-lite : 3.2.0
react : 17.0.1
react-dom : 17.0.1
react-scripts : 4.0.0

[urugator]

useEffect(() => {
    const fetch = flowResult(store.flowAction());
    // ---
    fetch.catch(error => console.log("CATCHED"));
    // ---
    return () => fetch.cancel();
  }, [store]);

[iChenLei]

issue Errors handing for effect callbacks
testing-library/react-hooks-testing-library#308

I think we should add usage(code example) to official document.
👉 https://mobx.js.org/actions.html#cancelling-flows-

urugtor's code snippt is a great solution.

[DMS40]

Oops! It's my mistake not to try that way. Thank you @urugator

I thought it should be handled inside the flow method!

I tried it on the actual product and it worked perfectly as I wanted.

@iChenLei
Should I close this issue? Or will you close it after considering what you were talking about?

Thank you for your time everyone!

[iChenLei]

https://mobx.js.org/actions.html#cancelling-flows-

@DMS40 please keep it until we get a unanimous view for Do we need mention this case in official doc , Thanks
Better doc , Better development experience 😄 @mweststrate Any suggestion ?

[mweststrate]

@iChenLei yeah it is probably good to mention that the promise returned from the flow will reject and can be catched. You can't catch it inside the flow itself, but as mentioned the finalization block will run so could be used to detect it.