Type issue when assigning a store with a reference

[RickLucassen]

Bug report

• I've checked documentation and searched for existing issues
• I've made sure my project is based on the latest MST version
• Fork this code sandbox or another minimal reproduction.

Sandbox link or minimal reproduction code
https://codesandbox.io/s/mobx-state-tree-todolist-forked-o9yj3

Describe the expected behavior
In the example we're defining a root store with another store as a property. That store has a property of type array of a model.
When that model doesn't have a types.reference present everything is fine. However, when the model does have a types.reference present typescript complains about an incorrect type.

Typescript should resolve these types correctly.

Describe the observed behavior
As seen in the rootStore, where there is a version with and without the reference, the one with the reference generates a typescript error about the someModel type not matching.

[RickLucassen]

It seems that wrapping the createTodoStoreWithReference with castToSnapshot does make it work. Would this be the proposed solution?

Still strange that without the castToSnapshot there is a difference in behavior between the two stores (with and without a reference).

[coolsoftwaretyler]

Hey @RickLucassen - sorry it took so long for anyone to get back to you here. We are trying to give some more care and attention here to MobX-State-Tree

I don't know for 100% sure that castToSnapshot is the best case solve, but if it did help your issue, that makes sense. There are some known issues with the TypeScript inferences in MST, and we're highly interested in fixing that.

If you're still having the problem, or if you solved it elsewise, I'd love to hear what worked for you. Or if you moved on, no worries.

For now, I'll leave this issue and label with with TS and help/PR welcome. Hopefully we can find some ways to improve this moving forward.