Errors thrown in autoruns are caught by mobx, errors thrown in reactions are not caught

[philipstanislaus]

Expected behavior

Errors thrown from reactions and autoruns are both caught, onReactionError handler is called for both.

Actual behavior

Errors thrown from reactions are not caught, onReactionError handler is not called.

Reproduction example

https://codesandbox.io/s/xr2nzz41zq

Steps to reproduce

1. Click on "Throw error in autorun", go to console => error is caught, onReactionError handler logs to console.
2. Click on "Throw error in reaction" => error is not caught, application crashes, onReactionError handler is not called.

Versions

mobx 4.1.0, mobx-react 5.0.0, react 16.0.0, react-dom 16.0.0

Template

2. Issue:

• Provide error messages including stacktrace
• Provide a minimal sample reproduction. Create a reproduction based on this sandbox
• Did you check this issue wasn't filed before?
• Elaborate on your issue. What behavior did you expect?
• State the versions of MobX and relevant libraries. Which browser / node / ... version?

[urugator]

Note it catches errors thrown in "tracking" part (first arg), but not in "effect" part (second arg). Dunno if it's intention or oversight.

[mweststrate]

Released a fix in 4.2.0

[philipstanislaus]

Thanks!