Bug: Signal Forms FieldTree as component param in MockRender corrupts parameter

[wimbarelds]

Description of the bug

When using signal forms, if a component has an input:

items = input.required<FieldTree<Item[]>>();

And a value for this is provided via MockRender / MockRenderFactory:

const factory = MockRenderFactory(MyComponent, ['items']);
const formState = signal({ items: [{name: 'test'}] });
const formModel = TestBed.runInInjectionContext(() => form(formState));

const fixture = factory({ items: formModel.items });
const component = fixture.point.componentInstance;
expect(component).toBeTruthy();

Produces the following error:

TypeError: newCollection[Symbol.iterator] is not a function

The same also happens if using MockRender directly without runInInjectionContext, however that also provides a warning saying that form(...) must be in an injection context.

An example of the bug

Link:
https://codesandbox.io/p/devbox/keen-river-xhh7tg

Expected vs actual behavior

Expected is no error.

Also...

1: I realize signal forms are experimental etc.
2: It's kind of a chore to have to use the MockRenderFactory to get signal forms 'form()into an injection context. It would be awesome if we could do something likeMockRender(MyComponent, () => ({ items: form(formState).items }))`, where the provided callback creates component parameters inside the injection context.