Avoid "value can be null" warning for extension method - flutter

Question

I am using an extension on Iterable that adds the following two methods
extension MyIterableExt<T> on Iterable<T> {
bool get isEmptyOrNull => this == null || this.isEmpty;
bool get isNotEmptyOrNull => this != null && this.isNotEmpty;
}
This works as I expected, but when I try to use it in statements where the receiver can be null, I get a warning in IntelliJ. For example, the following code works and prints true:
List<String> x;
print('${x?.reversed.isEmptyOrNull}');
Is there any way I can make the Dart Analyzer understand that the extension checks if this == null and thus not show the warning?
Please note that I do not want to have to add suppression directives to every file or line where I use this extension!
I know I can add // ignore_for_file: can_be_null_after_null_aware or // ignore: can_be_null_after_null_aware to make the warning go away, but what I'm looking for is a way to make the Dart Analyzer understand that the warning for this particular extension method is not needed.
This is in a non null-safe project, if that matters.

Answer 1

you can make Iterable Nullable
extension MyIterableExt<T> on Iterable<T>? {
bool get isEmptyOrNull => this == null || this!.isEmpty;
bool get isNotEmptyOrNull => this != null && this!.isNotEmpty;
}

Answer 2

Make extension base on Iterable? is the way, if you have to find something to disable the warning but not want to change the code then im sorry cause i never do that before.
void main() {
Iterable? a = [];
Iterable b = ['1', '2', '3'];
print('a.isEmptyOrNull: ${a.isEmptyOrNull}');
print('b.isEmptyOrNull: ${b.isEmptyOrNull}');
print('a.isNotEmptyOrNull: ${a.isNotEmptyOrNull}');
print('b.isNotEmptyOrNull: ${b.isNotEmptyOrNull}');
}
extension on Iterable? {
bool get isEmptyOrNull => this == null || this!.isEmpty;
bool get isNotEmptyOrNull => this != null && this!.isNotEmpty;
}
result
a.isEmptyOrNull: true
b.isEmptyOrNull: false
a.isNotEmptyOrNull: false
b.isNotEmptyOrNull: true

Answer 3

Based on the Flutter docs, you should be able to add a comment at the top of your code that will essentially disable null safety checks:
// #dart=2.9
import 'src/my_app.dart';
main() {
//...
}
You should be able to put that comment at the top of any specific file you want this behavior. It doesn't have to be in your "main" file.