updateField method Null safety

FormData updateField(
  1. FormField field
)

Implementation

FormData updateField(FormField field) {
  final fields = List<FormField>.from(this.fields);
  final index = fields.toList().indexWhere((f) => field.isSameKey(f));
  if (index == -1) {
    fields.add(field);
  } else {
    fields[index] = field;
  }
  return FormData(fields: fields);
}