Modifiers are not sticky when reassigning to @observable fields

[jeffijoe]

As discussed with @mweststrate on Discord.

When using the @observable decorator, modifiers are not sticky when reassigning.

Example:

class Stuff {
  @observable thingy = asFlat([]);

  constructor() {
    // Not sure if this is the cause..
    transaction(() => {
      this.thingy = [{more: 'stuff'}];
    });
  }
}

[mweststrate]

Note that thing.replace([{more: 'stuff'}]) can currently be used to work around this.

[mweststrate]

Stickyness is now solved by introducing additional decorators / modifiers. From MobX 3 onward one should use: @observable.shallow thing = [], which will be sticky

Closing this issue as [email protected] is now available, which addresses this issue. Changelog: https://github.com/mobxjs/mobx/blob/mobx3/CHANGELOG.md#300. The changes in more details: https://github.com/mobxjs/mobx/pull/725/files. Feel free to re-open if questions arise!

[jeffijoe]

My man! 👍