Extensions for getters don't work on classes that define a setter with the same name.

[jellynoone]

Consider:

// submit
void main(List<String> args) {
  A().a; // not found
}

class A {
  set a(int value) {}
}

extension on A {
  int get a => 0;
}

The .a access is not found even though there is an extension on A that defines it. I'm not sure if this is intended or not considering A defines a setter?

Concrete example, where fixing this bug would be useful:

// Assuming flutter:
abstract interface class ValueListenable<T> {
  T get value;
  void addListener(void Function() listener);
  void removeListener(void Function() listener);
}

// package:library
abstract interface class MyController {
  ValueListenable<MyState> get state;

  set a(int a);
}

class MyState {
  final int a;

  const MyState({
    required this.a,
  });
}

// my_app
void main() {
  final controller = MyController();

  print(controller.a); // Accessing the value of 'a' from `MyState` via getter 
}

extension on MyController {
  int get a => state.value.a;
}

dart --version
Dart SDK version: 3.7.2 (stable) (Tue Mar 11 04:27:50 2025 -0700) on "macos_arm64"

[FMorschel]

This was discussed at #60203 (comment).

@lrhn

[lrhn]

Yes, this is intended.

[FMorschel]

Also, this is the current issue for making a better devexp for this #60210.

[johnniwinther]

Closing this issue, delegating to #60210.