Use '@override' decorator for methods overriden by subclass

[gcattan]

Hello,

I updated a project from mobx 4 to mobx 6.6.1 and I encountered the error:

[MobX] Cannot apply '@observable' to ...: The field is already decorated with '@observable'. Re-decorating fields is not allowed. Use '@override' decorator for methods overriden by subclass.

The same error also appear with the the decorator '@action'.

The project is quiet big and there is a lot of places where I need to handle the suggested change.

Is there a convenient way to avoid this refactoring, and have a consistent behavior with mobx 4?

Thanks :)

[kubk]

Hi, as far as I know there is no way to automate this

[kubk]

TypeScript has a setting to force adding override TS keyword to child's methods: https://dev.to/lioness100/introducing-typescript-override-keyword-4b36

It is not the same as adding Mobx override keyword, but it might be helpful to run it once to detect what methods require adding @override Mobx decorator

[gcattan]

Hm. OK. I will try to do this, but we have around 2-3 thousand of methods with implicit override and almost the same number of reference to @action and @observable.
Is there a lower version of mobx 6 where this behavior does not exists and that I can use in case?

[urugator]

Is there a lower version of mobx 6 where this behavior does not exists

< 6.1, but especially inheritance was quite broken (therefore the rework)

what methods require adding @OverRide Mobx decorator

Just to clarify a bit, @override is not (at least at the moment) required, leaving overriden field in subclass non-decorated is enough.

[gcattan]

Hi,
Thanks for the explanation and sorry for the delay in my response. It took some time, but I proceeded with the typescript settings as suggested to replace all the references.
Because the project is big, I left the @observable in place and use makeObservable(this) in the store as indicated in the doc. However, the render method calls exceed the react limit. It look like I am missing an additional setting, but I cannot find where.