TypeError: 'set' on proxy: trap returned falsish for property '__proto__'

[lvvlan]

Pls help, why is not working

This is demo https://codesandbox.io/s/lj3l95m09

Thx!

[kuitos]

The component which you used try to re-define the property of observable of mobx, use a non-mobx observable data or observable.ref instead.

class Model {
  @observable.ref
  data = []
}

[lvvlan]

Thx~ But if use @observable.ref, the changes in model do not respond to view，How should I do？

[kuitos]

do not modify the array with push or splice or such way, modify the reference instead. check the doc https://mobx.js.org/refguide/modifiers.html#reference-observability

[lvvlan]

Thx very much! But I don't understand what do u mean modify the reference instead, If I use @observable.ref, It means I can't change model？?
This is simple demo https://codesandbox.io/s/lj3l95m09, that use @observable.ref, how should I change the model, it can be respond to view?

[kuitos]

What u decorated with observable.ref was val rather than the nested val.b.test, so re-assign val with a new reference then the reaction would be triggered.

handleChangeModel() {
    this.model.val.b.test = [
      {
        time: "我被改变了！"
      }
    ];
    this.model.val = {...this.model.val}
  }

To achieve the immutable approach u could try immer to reduce the verbose boilerplate code.

[lvvlan]

sorry sorry I'm wrong and update https://codesandbox.io/s/lj3l95m09
I think this.model= {...this.model}, u mean a new reference then the reaction would be triggered. however that mobx-vue is not used, because @Observer will replace Vue Watcher, right?

[lvvlan]

but this.model.val = {...this.model.val} can be update view, because I changed the reference, right?

[kuitos]

yep, observable.ref only react to reference changing

[Nemikolh]

Hi,
I am also seeing a similar error after migrating vuejs from 2.5.17 to 2.5.18. However, I can't use observable.ref or pass { deep: false } to my observable as it breaks some of my observer. The codebase is relatively big, I will try to provide a minimal reproduction link.

Does that problem sounds familiar?

[Nemikolh]

Ok, so I managed to reproduce the problem: https://codesandbox.io/s/p7zwrvjrz7.

I'm really annoyed because it used to work until we had to update vuetify which in turns forced us to update vue to at least version 2.5.18. Maybe this bug should be reported on the vuejs repo?

EDIT: A simpler example that does not use vuetify: https://codesandbox.io/s/k90k8kwn2r

Note: To see the error select an item

[Nemikolh]

After investigating more this PR vuejs/vue#7828 broke mobxjs/mobx-vue.
@kuitos, I see several options:

• Submit a PR to github.com/mobxjs/mobx to allow setting __proto__ in some way. Not sure of the implication of the change.
• Submit a PR to github.com/vuejs/vue to skip object of type Proxy.
• Do something in this library? However I'm not sure if there's anything that can be done...

[Nemikolh]

@kuitos: Could you re-open this issue until a solution is found?

[kuitos]

@Nemikolh Thanks for your great efforts, I will look into it this weekend:smiley: