Extension types on JS types generate suboptimal method invocations

[leonsenft]

I just tried rewriting some use of package:js to dart:js_interop and noticed that it generates rather inefficient function invocations:

@JS('signals')
library dart.signals;

@JS('s')
external WritableSignal<T> _signal<T>(ExternalDartReference? initialValue);

WritableSignal<T> signal<T>(T initialValue) =>
    _signal(initialValue?.toExternalReference);

Previously, this snippet:

void main() {
  final x = signal(1);
  ...
}

Produced a direct call to the function s:

main() {
  var x = signals.s(1);
  ...
}

After switching to dart:js_interop, it now generates:

A = {
  callMethod(o, method, args) {
    return o[method].apply(o, args);
  },
  signal(initialValue) {
    var t1 = self.signals;
    return A.callMethod(t1, "s", [initialValue]);
  },
  ...
};

main() {
  var x = A.signal(1);
}

The previous code seems more efficient and smaller–is there a rationale for this change or is it perhaps a regression?