- Fix bug in auto dispose where signal causes cycle

- Fix bug in auto dispose where signal causes cycle
- add private reset
- dispose does not reset to initial value and will read the last value with a warning

packages/signals_core/lib/src/async/signal.dart

@@ -45,8 +45,9 @@ class AsyncSignal<T> extends ValueSignal<AsyncState<T>> {
     _completer = Completer<bool>();
   }
 
-  void reset() {
-    value = _initialValue;
+  @override
+  void reset([AsyncState<T>? value]) {
+    this.value = value ?? _initialValue;
     _initialized = false;
     _completer = Completer<bool>();
   }

packages/signals_core/lib/src/async/stream.dart

@@ -109,8 +109,8 @@ class StreamSignal<T> extends AsyncSignal<T> {
   }
 
   @override
-  void reset() {
-    super.reset();
+  void reset([AsyncState<T>? value]) {
+    super.reset(value);
     _fetching = false;
     _done = false;
     _subscription?.cancel();

packages/signals_core/lib/src/core/computed.dart

@@ -201,6 +201,9 @@ class _Computed<T> implements Computed<T>, _Listenable {
         }
       }
     }
+    if (autoDispose && _allTargets.isEmpty) {
+      dispose();
+    }
   }
 
   @override
@@ -239,7 +242,8 @@ class _Computed<T> implements Computed<T>, _Listenable {
   T get value {
     if (disposed) {
       if (kDebugMode) {
-        print('computed warning: [$globalId|$debugLabel] has been read after disposed');
+        print(
+            'computed warning: [$globalId|$debugLabel] has been read after disposed');
       }
       return this._value;
     }
@@ -296,19 +300,22 @@ class _Computed<T> implements Computed<T>, _Listenable {
 
   @override
   void dispose() {
+    if (disposed) return;
     for (final cleanup in _disposeCallbacks) {
       cleanup();
     }
     _disposeCallbacks.clear();
     _flags |= DISPOSED;
-    if (_node != null) _unsubscribe(_node!);
-    _value = _initialValue;
-    _previousValue = _initialValue;
     disposed = true;
   }
 
   @override
   T get initialValue => _initialValue;
+
+  void reset([T? value]) {
+    _value = value ?? _initialValue;
+    _previousValue = value ?? _initialValue;
+  }
 }
 
 typedef ComputedCallback<T> = T Function();

packages/signals_core/lib/src/core/signal.dart

@@ -227,13 +227,15 @@ class _Signal<T> extends Signal<T> {
         signal._targets = next;
       }
     }
-    if (signal.autoDispose && signal._allTargets.isEmpty) {
-      signal.dispose();
-    }
   }
 
   @override
-  void _unsubscribe(_Node node) => __unsubscribe(this, node);
+  void _unsubscribe(_Node node) {
+    __unsubscribe(this, node);
+    if (autoDispose && _allTargets.isEmpty) {
+      dispose();
+    }
+  }
 
   @override
   EffectCleanup subscribe(void Function(T value) fn) {
@@ -363,14 +365,17 @@ class _Signal<T> extends Signal<T> {
 
   @override
   void dispose() {
+    if (disposed) return;
     for (final cleanup in _disposeCallbacks) {
       cleanup();
     }
-    if (_node != null) _unsubscribe(_node!);
-    _value = _initialValue;
-    _previousValue = _initialValue;
     disposed = true;
   }
+
+  void reset([T? value]) {
+    _value = value ?? _initialValue;
+    _previousValue = value ?? _initialValue;
+  }
 }
 
 /// The `signal` function creates a new signal. A signal is a container

packages/signals_core/test/core/signals_test.dart

@@ -84,6 +84,45 @@ void main() {
         expect(() => s.value = [3], throwsA(isA<SignalsError>()));
         // expect(() => s.value, throwsA(isA<SignalsError>()));
       });
+
+      test('should autoDispose signal when it has no listeners', () {
+        var count = signal(2, autoDispose: true);
+        var multiple = signal(2);
+        var product = computed(() => count() * multiple());
+
+        expect(count.value, 2);
+        expect(multiple.value, 2);
+        expect(product.value, 4);
+
+        count.onDispose(() => print('disposed count'));
+        product.onDispose(() => print('disposed doubled'));
+
+        count.value = 3;
+        multiple.value = 3;
+
+        expect(count.value, 3);
+        expect(multiple.value, 3);
+        expect(product.value, 9);
+
+        // simulate widget listeners
+        var unmount = effect(() {
+          print('count: ${count.value}');
+          print('product: ${product.value}');
+        });
+
+        // simulate widget unmount
+        unmount();
+
+        expect(count.disposed, isTrue);
+        expect(multiple.disposed, isFalse);
+        expect(product.disposed, isFalse);
+
+        multiple.value = 4; // update signal that's not autodisposed
+
+        print('count: ${product.value}');
+
+        expect(product.value, 12);
+      });
     });
 
     test('should inherit from Signal', () {