Hi! I'm seeing some unexpected behavior with using ExtensionMacro. According to SE-0402[1] we can expect that an ExtensionMacro applied to a nested type will generate an extension at top-level. I am testing with an ExtensionMacro example from the swift-syntax repo and I am seeing the extension generated at local scope:
struct Outer {
@Observable
struct Inner {}
}
Expands to:
struct Outer {
struct Inner {
let _registrar = ObservationRegistrar<Inner >()
public nonisolated func addObserver(_ observer: some Observer<Inner >) {
_registrar.addObserver(observer)
}
public nonisolated func removeObserver(_ observer: some Observer<Inner >) {
_registrar.removeObserver(observer)
}
private func withTransaction<T>(_ apply: () throws -> T) rethrows -> T {
_registrar.beginAccess()
defer {
_registrar.endAccess()
}
return try apply()
}
private struct Storage {
}
private var _storage = Storage()
}
extension Outer.Inner: Observable {
}
}
Is this a known issue being tracked? I've searched through forums and GitHub and I didn't see this already. Is there any place I can follow along to learn more about a potential fix or workaround? Thanks!
Here is a diff on swift-syntax to repro:
diff --git a/Examples/Sources/MacroExamples/Playground/main.swift b/Examples/Sources/MacroExamples/Playground/main.swift
index 6df22c09..00df357b 100644
--- a/Examples/Sources/MacroExamples/Playground/main.swift
+++ b/Examples/Sources/MacroExamples/Playground/main.swift
@@ -84,6 +84,11 @@ print("Point storage contains only the value we set: \(point)")
// MARK: - ObservableMacro
+struct Outer {
+ @Observable
+ struct Inner {}
+}
+
struct Treat {}
@Observable
