FormArray of array element does not work properly

[duydnguyen07]

Is this a regression?

No

Description

Version: ^4.1.0

Given the following interface

interface Example {
   positions: [number, number][];
}

When I create a FormGroup from the above interface, the type of positions is determined to be FormGroup instead of FormArray. I expect it to be a FormArray because it's an array, not an object.

const group = new FormGroup<ControlsOf>({ positions: new FormArray([ new FormControl(0), new FormControl(0) ]) // This throws an error because FormArray is not FormGroup. });

Please provide a link to a minimal reproduction of the bug

No response

Please provide the exception or error you saw

Type 'FormArray<[number, number], FormArray<number, FormControl<number>>>' is not assignable to type 'FormArray<[number, number], FormGroup<[FormControl<number>, FormControl<number>]>>'.
  Type 'FormArray<number, FormControl<number>>' is missing the following properties from type 'FormGroup<[FormControl<number>, FormControl<number>]>': registerControl, addControl, removeControl, contains

Please provide the environment you discovered this bug in

No response

Anything else?

No response

Do you want to create a pull request?

Yes

[NetanelBasal]

You're welcome to create a PR.