Add a way to unregister life-cycle listeners

packages/riverpod/CHANGELOG.md

@@ -24,6 +24,8 @@
 - **Breaking**: A provider is now considered "paused" if all
   of its listeners are also paused. So if a provider `A` is watched _only_ by a provider `B`, and `B` is currently unused,
   then `A` will be paused.
+- All `Ref` life-cycles (such as `Ref.onDispose`) and `Notifier.listenSelf`
+  now return a function to remove the listener.
 - Added methods to `ProviderObserver` for listening to "mutations".
   Mutations are a new code-generation-only feature. See riverpod_generator's changelog
   for more information.

packages/riverpod/lib/riverpod.dart

@@ -22,7 +22,6 @@ export 'src/framework.dart'
         ProviderElementProxy,
         OnError,
         ProviderContainerTest,
-        DebugRiverpodDevtoolBiding,
         TransitiveFamilyOverride,
         TransitiveProviderOverride,
         $ProviderPointer,

packages/riverpod/lib/src/core/provider/notifier_provider.dart

@@ -65,12 +65,14 @@ abstract class NotifierBase<StateT, CreatedT> {
   /// As opposed to [Ref.listen], the listener will be called even if
   /// [updateShouldNotify] returns false, meaning that the previous
   /// and new value can potentially be identical.
+  ///
+  /// Returns a function which can be called to remove the listener.
   @protected
-  void listenSelf(
+  RemoveListener listenSelf(
     void Function(StateT? previous, StateT next) listener, {
     void Function(Object error, StackTrace stackTrace)? onError,
   }) {
-    $ref.listenSelf(listener, onError: onError);
+    return $ref.listenSelf(listener, onError: onError);
   }
 
   @visibleForTesting

packages/riverpod/lib/src/core/provider_container.dart

@@ -636,7 +636,6 @@ class ProviderContainer implements Node {
     // This ensures that if an error is thrown, the parent & global state
     // are not affected.
     parent?._children.add(this);
-    if (kDebugMode) DebugRiverpodDevtoolBiding.addContainer(this);
   }
 
   /// An automatically disposed [ProviderContainer].
@@ -954,10 +953,6 @@ class ProviderContainer implements Node {
     for (final element in getAllProviderElementsInOrder().toList().reversed) {
       element.dispose();
     }
-
-    if (kDebugMode) {
-      DebugRiverpodDevtoolBiding.removeContainer(this);
-    }
   }
 
   /// Release all the resources associated with this [ProviderContainer].

packages/riverpod/lib/src/core/ref.dart

@@ -257,24 +257,32 @@ final <yourProvider> = Provider(dependencies: [<dependency>]);
 
   /// A life-cycle for whenever a new listener is added to the provider.
   ///
+  /// Returns a function which can be called to remove the listener.
+  ///
   /// See also:
   /// - [onRemoveListener], for when a listener is removed
-  void onAddListener(void Function() cb) {
+  RemoveListener onAddListener(void Function() cb) {
     _throwIfInvalidUsage();
 
-    _onAddListeners ??= [];
-    _onAddListeners!.add(cb);
+    final list = _onAddListeners ??= [];
+    list.add(cb);
+
+    return () => list.remove(cb);
   }
 
   /// A life-cycle for whenever a listener is removed from the provider.
   ///
+  /// Returns a function which can be called to remove the listener.
+  ///
   /// See also:
   /// - [onAddListener], for when a listener is added
-  void onRemoveListener(void Function() cb) {
+  RemoveListener onRemoveListener(void Function() cb) {
     _throwIfInvalidUsage();
 
-    _onRemoveListeners ??= [];
-    _onRemoveListeners!.add(cb);
+    final list = _onRemoveListeners ??= [];
+    list.add(cb);
+
+    return () => list.remove(cb);
   }
 
   /// Add a listener to perform an operation when the last listener of the provider
@@ -287,35 +295,43 @@ final <yourProvider> = Provider(dependencies: [<dependency>]);
   /// _will_ get paused/dispose. It is possible that after the last listener
   /// is removed, a new listener is immediately added.
   ///
+  /// Returns a function which can be called to remove the listener.
+  ///
   /// See also:
   /// - [keepAlive], which can be combined with [onCancel] for
   ///   advanced manipulation on when the provider should get disposed.
   /// - [Provider.autoDispose], a modifier which tell a provider that it should
   ///   destroy its state when no longer listened to.
   /// - [onDispose], a life-cycle for when a provider is disposed.
   /// - [onResume], a life-cycle for when the provider is listened to again.
-  void onCancel(void Function() cb) {
+  RemoveListener onCancel(void Function() cb) {
     _throwIfInvalidUsage();
 
-    _onCancelListeners ??= [];
-    _onCancelListeners!.add(cb);
+    final list = _onCancelListeners ??= [];
+    list.add(cb);
+
+    return () => list.remove(cb);
   }
 
   /// A life-cycle for when a provider is listened again after it was paused
   /// (and [onCancel] was triggered).
   ///
+  /// Returns a function which can be called to remove the listener.
+  ///
   /// See also:
   /// - [keepAlive], which can be combined with [onCancel] for
   ///   advanced manipulation on when the provider should get disposed.
   /// - [Provider.autoDispose], a modifier which tell a provider that it should
   ///   destroy its state when no longer listened to.
   /// - [onDispose], a life-cycle for when a provider is disposed.
   /// - [onCancel], a life-cycle for when all listeners of a provider are removed.
-  void onResume(void Function() cb) {
+  RemoveListener onResume(void Function() cb) {
     _throwIfInvalidUsage();
 
-    _onResumeListeners ??= [];
-    _onResumeListeners!.add(cb);
+    final list = _onResumeListeners ??= [];
+    list.add(cb);
+
+    return () => list.remove(cb);
   }
 
   /// Adds a listener to perform an operation right before the provider is destroyed.
@@ -357,18 +373,22 @@ final <yourProvider> = Provider(dependencies: [<dependency>]);
   ///   if an exception happens before [onDispose] is called, then
   ///   some of your objects may not be disposed.
   ///
+  /// Returns a function which can be called to remove the listener.
+  ///
   /// See also:
   ///
   /// - [Provider.autoDispose], a modifier which tell a provider that it should
   ///   destroy its state when no longer listened to.
   /// - [ProviderContainer.dispose], to destroy all providers associated with
   ///   a [ProviderContainer] at once.
   /// - [onCancel], a life-cycle for when all listeners of a provider are removed.
-  void onDispose(void Function() listener) {
+  RemoveListener onDispose(void Function() listener) {
     _throwIfInvalidUsage();
 
-    _onDisposeListeners ??= [];
-    _onDisposeListeners!.add(listener);
+    final list = _onDisposeListeners ??= [];
+    list.add(listener);
+
+    return () => list.remove(listener);
   }
 
   /// Read the state associated with a provider, without listening to that provider.
@@ -611,7 +631,7 @@ class _Ref<StateT> extends Ref {
   /// As opposed to [listen], the listener will be called even if
   /// [ProviderElement.updateShouldNotify] returns false, meaning that the previous
   /// and new value can potentially be identical.
-  void listenSelf(
+  RemoveListener listenSelf(
     void Function(StateT? previous, StateT next) listener, {
     void Function(Object error, StackTrace stackTrace)? onError,
   }) {
@@ -622,6 +642,11 @@ class _Ref<StateT> extends Ref {
       _onErrorSelfListeners ??= [];
       _onErrorSelfListeners!.add(onError);
     }
+
+    return () {
+      _onChangeSelfListeners?.remove(listener);
+      _onErrorSelfListeners?.remove(onError);
+    };
   }
 }
 

packages/riverpod/lib/src/framework.dart

@@ -6,6 +6,7 @@ import 'dart:math' as math;
 
 import 'package:collection/collection.dart';
 import 'package:meta/meta.dart';
+import 'package:state_notifier/state_notifier.dart';
 import 'package:test/test.dart' as test;
 import 'common/env.dart';
 import 'common/pragma.dart';
@@ -27,5 +28,4 @@ part 'core/modifiers/select.dart';
 part 'core/scheduler.dart';
 part 'core/override_with_value.dart';
 part 'core/override.dart';
-part 'core/devtool.dart';
 part 'core/modifiers/future.dart';

packages/riverpod/test/src/core/provider_container_test.dart

@@ -81,11 +81,6 @@ TypeMatcher<ProviderDirectory> isProviderDirectory({
 }
 
 void main() {
-  tearDown(() {
-    // Verifies that there is no container leak.
-    expect(DebugRiverpodDevtoolBiding.containers, isEmpty);
-  });
-
   group('ProviderPointerManager', () {
     group('findDeepestTransitiveDependencyProviderContainer', () {
       final transitiveDependency = Provider(
@@ -1025,13 +1020,6 @@ void main() {
         );
       });
 
-      test('registers itself in the container list', () {
-        final container = ProviderContainer();
-        addTearDown(container.dispose);
-
-        expect(DebugRiverpodDevtoolBiding.containers, [container]);
-      });
-
       test('throws if "parent" is disposed', () {
         final root = ProviderContainer();
         root.dispose();
@@ -1046,11 +1034,6 @@ void main() {
           isEmpty,
           reason: 'Invalid containers should not be added as children',
         );
-        expect(
-          DebugRiverpodDevtoolBiding.containers,
-          isEmpty,
-          reason: 'Invalid containers should not be added to the global list',
-        );
       });
 
       test('if parent is null, assign "root" to "null"', () {
@@ -1812,17 +1795,6 @@ void main() {
         expect(callCount, 0);
       });
 
-      test('unregister itself from the container list', () {
-        final container = ProviderContainer();
-        addTearDown(container.dispose);
-
-        expect(DebugRiverpodDevtoolBiding.containers, [container]);
-
-        container.dispose();
-
-        expect(DebugRiverpodDevtoolBiding.containers, isEmpty);
-      });
-
       test('Disposes its children first', () {
         final rootOnDispose = OnDisposeMock();
         final childOnDispose = OnDisposeMock();