decorated, un-assigned no longer throws error (and breaks action.bound)

[alisman]

In trying to upgrade Mobx 4 to 6, we just spent a few hours debugging a situation where we han observable decorator on an un-assigned class property. This curiously caused action.bound decorator to fail on an unrelated method! I understand we are kind of asking for trouble by continuing to use the now marginalized decorators (true/false?) but our code base is so dependent on them and we also really like them. But anyhow, i think there used to be an error message when you left an observable undefined? Anyway we can catch this so we don't run into it again?

class something {
 
    // leaving this un-assigned is illegal and strangely breaks the action.bound below
    // must be something with the way decorators are now handled
    @observable someVar;

    @action.bound doSomething(){
           // this is not bound due to the un-assigned property
    }

}

[mweststrate]

Did you update your compiler settings according to the migration guide? Can you provide a minimal repro?

…

On Tue, 1 Dec 2020, 00:03 alisman, ***@***.***> wrote: In trying to upgrade Mobx 4 to 6, we just spent a few hours debugging a situation where we han observable decorator on an un-assigned class property. This curiously caused action.bound decorator to fail on an unrelated method! I understand we are kind of asking for trouble by continuing to use the now marginalized decorators (true/false?) but our code base is so dependent on them and we also really like them. But anyhow, i think there used to be an error message when you left an observable undefined? Anyway we can catch this so we don't run into it again? ` class something { // leaving this un-assigned is illegal and strangely breaks the action.bound below // must be something with the way decorators are now handled @observable someVar; @action.bound doSomething(){ // this is not bound due to the un-assigned property } } ` — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#2655>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAN4NBC2EN2DTQAROGOOOCDSSQXGNANCNFSM4UIIPKQQ> .

[alisman]

We will double check compiler settings, thanks! @mweststrate just wanted to say a huge thank you. it is INCREDIBLE that you respond to these kind of messages. i hope that FB is paying you very well b/c you deserve to be rewarded for your contribution to web development. Mobx is at the heart of our application at cbioportal.org, a data visualization platform that is used by cancer researchers all around the world. So, kudos to you.