Issues with types and inheritances of those when used inside FormGroup about angular HOT 2 CLOSED

If you change new FormGroup(...) to new FormGroup<T>(...) you'll get

Argument of type '{ codipostalMercaderies_input: FormControl<string>; katr10_input: FormControl<boolean>; nomMercaderies_input: FormControl<string>; poblacioMercaderies_input: FormControl<...>; ... 20 more ...; pais_input: FormControl<...>; }' is not assignable to parameter of type 'T'.
  'T' could be instantiated with an arbitrary type which could be unrelated to '{ codipostalMercaderies_input: FormControl<string>; katr10_input: FormControl<boolean>; nomMercaderies_input: FormControl<string>; poblacioMercaderies_input: FormControl<...>; ... 20 more ...; pais_input: FormControl<...>; }'.

which exposes a real problem with this code, unrelated to the typings of @angular/forms: T may require additional properties that are not present in the FormGroup's controls object.

The error message isn't great here due to @angular/forms's complexity to support typed forms in a backwards compatible way, but it's fundamentally an issue with your code.

from angular.

As @JoostK explains, he type error is a bit hard to parse here, but is correct.

parent declares a generic type T with the bound of extends iZmerControls. This type could be iZmerControls, or it could be some type which extends iZmerControls and adds extra controls. For example:

interface MyControls extends iZmerControls {
  someName: FormControl<number>;
}

new parent<MyControls>();

What TypeScript is telling you is that new FormGroup({...}) in parent can't be proven to satisfy T, since it might be missing controls which are present in the extended T. For example, it would be missing someName in the case of new parent<MyControls> above.

from angular.