Can't make @observable parameter properties

[JoshuaKGoldberg]

I have an:

2. Issue:

• Provide error messages including stacktrace
• Provide a minimal sample reproduction.
• 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?

MobX version: 3.3.1
TypeScript version: 2.7.0-dev.20171126

import { observable } from "mobx";

type Model = { };

export class ViewModel {
    public constructor(
        // Argument of type 'number' is not assignable to parameter of type 'PropertyDescriptor | undefined'.
        @observable
        public readonly model: Model,
    ) { }
}

On the other hand, works:

export class ViewModel {
    @observable
    public readonly model: Model;

    public constructor(model: Model) {
        this.model = model;
    }
}

[JoshuaKGoldberg]

Not sure if microsoft/TypeScript#10777 is relevant here.

[mweststrate]

We might implement this ones decorators are standardized. For now blocked until then as there is an easy workaround.

[mweststrate]

Closing for now, will be reopened once #1928 happens.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs or questions.