modelFlow has to be used over functions

[aboyer1013]

Looking for some guidance here with regards to errors when using inheritance with abstract classes. I'm not sure if this is a mobx-keystone bug or a misunderstanding of abstract classes and how they work in TypeScript.

I have to declare the method (fetch2) in the base class in order to resolve the error. Essentially, a noop filler just to get rid of the error. I have some questions:

1. Why does it complain about modelFlow but not the same for modelAction?
2. Is there a better way to do this?

I appreciate any feedback. Thanks!

Code Sandbox demo

import {
  _async,
  _await,
  ExtendedModel,
  model,
  Model,
  modelFlow,
  idProp,
  prop,
  modelAction
} from "mobx-keystone";

abstract class BaseModel extends Model({
  id: idProp,
  name: prop<string>()
}) {
  // If this method is removed, the error goes away.
  @modelFlow
  fetchData = _async(function* (this: BaseModel) {
    const promise = new Promise((resolve) => {
      setTimeout(() => {
        resolve("done");
      }, 3000);
    });
    const response = yield* _await(promise);

    console.log("response: ", response);
  });

  // In order to resolve, this method must be declared in the base model. Uncomment the next line to resolve.
  // fetch2: () => void = () => {}
}

// If this class is removed, the error goes away.
@model("ModelA")
class A extends ExtendedModel(BaseModel, {
  foo: prop<string>()
}) {}

@model("ModelB")
class B extends ExtendedModel(BaseModel, {
  foo: prop<string>()
}) {
  // The existence of fetch2 produces an error: modelFlow has to be used over functions
  @modelFlow
  fetch2 = _async(function* (this: BaseModel) {
    const promise = new Promise((resolve) => {
      setTimeout(() => {
        resolve("done");
      }, 3000);
    });
    const response = yield* _await(promise);

    console.log("response: ", response);
  });

  @modelAction
  something() {
    this.foo = "foo";
  }
}

const a = new A({
  foo: "bar",
  name: "test"
});

console.log(a.name);

[xaviergonz]

@aboyer1013 fixed in 0.69.2

[aboyer1013]

I'm back in business. Thanks for fixing this!