Print form groups validity

form_group_printer.ts

printValidility(formGroup: FormGroup) {
  return Object.keys(formGroup.controls).reduce((acc, current) => {
    if ((formGroup.controls[current] as FormGroup).controls) {
      acc[current] = this.printValidility(formGroup.controls[current] as FormGroup);
    } else {
      acc[current] = formGroup.controls[current].valid;
    }
    return acc;
  }, {});
}