class Disposable {
  disposed = false;

  [Symbol.dispose]() {
      this.disposed = true
  }
}

const disposables = [new Disposable()]

for (using _ of disposables) {/* ... */}

if (disposables[0].disposed) {
  console.log("✅ dispose ok")
} else {
  console.error("💥 failed to dispose")
}

class AsyncDisposable {
  disposed = false;

  [Symbol.asyncDispose]() {
      this.disposed = true
  }
}

const asyncDisposables = [new AsyncDisposable()]

for (await using _ of asyncDisposables) {/* ... */}

if (asyncDisposables[0].disposed) {
  console.log("✅ async dispose ok")
} else {
  console.error("💥 failed to async dispose")
}