mobx-utils | Utility functions and common patterns for MobX | State Container library

First of all, do you really need to memoize such simple operation? Or is it just an example?

Second, if you need just to memoize you don't need createTransformer at all, it serves a bit different purpose. But you can use computedFn, like that:

Input is not editable because if you call this const vm = createViewModel(company) inside render then each time new viewModel will be created from your company and all your fields will be reset basically.

What you can do is also just store your ViewModel inside state so it reference will be preserved between re renders.