How do I add mobx typescript support?

Question

As what you can see, the "replace" method is not support by ts. Maybe I should use IObservableArray instead of Array, but another problem occurred.

Answer 1

There are a few solutions. but yes you should use IObservableArray so you make sure you have and use the right methods.

I used this work around:

 this.files = [] as any;

or a more cast type once solution:

 function MyArray<T>(): IObservableArray<T> {
     return [] as any; // disable eslint once here.
 }

 this.files = MyArray();

Advised solution

This issue was discussed before on github: https://github.com/mobxjs/mobx/issues/669

The solution provided is to set it as readonly property once:

class AppModel {
  readonly files = observable<IFile>([])
}

this is the shortest typed solution that also makes sure you wont set this.files again mistakenly (and losing all your observers).