feat(xep): Improve the ergonomics of Bind2 negotiators

packages/moxxmpp/lib/src/xeps/xep_0198/negotiator.dart

@@ -28,7 +28,7 @@ enum _StreamManagementNegotiatorState {
 ///       StreamManagementManager at least once before connecting, if stream resumption
 ///       is wanted.
 class StreamManagementNegotiator extends Sasl2FeatureNegotiator
-    implements Bind2FeatureNegotiator {
+    implements Bind2FeatureNegotiatorInterface {
   StreamManagementNegotiator()
       : super(10, false, smXmlns, streamManagementNegotiator);
 
@@ -256,6 +256,9 @@ class StreamManagementNegotiator extends Sasl2FeatureNegotiator
     ];
   }
 
+  @override
+  Future<void> onBind2Success(XMLNode response) async {}
+
   @override
   Future<List<XMLNode>> onSasl2FeaturesReceived(XMLNode sasl2Features) async {
     final inline = sasl2Features.firstTag('inline')!;

packages/moxxmpp/lib/src/xeps/xep_0280.dart

@@ -9,11 +9,8 @@ import 'package:moxxmpp/src/managers/handlers.dart';
 import 'package:moxxmpp/src/managers/namespaces.dart';
 import 'package:moxxmpp/src/namespaces.dart';
 import 'package:moxxmpp/src/negotiators/namespaces.dart';
-import 'package:moxxmpp/src/negotiators/negotiator.dart';
-import 'package:moxxmpp/src/negotiators/sasl2.dart';
 import 'package:moxxmpp/src/stanza.dart';
 import 'package:moxxmpp/src/stringxml.dart';
-import 'package:moxxmpp/src/types/result.dart';
 import 'package:moxxmpp/src/xeps/xep_0030/xep_0030.dart';
 import 'package:moxxmpp/src/xeps/xep_0297.dart';
 import 'package:moxxmpp/src/xeps/xep_0386.dart';
@@ -202,9 +199,8 @@ class CarbonsManager extends XmppManagerBase {
   }
 }
 
-class CarbonsNegotiator extends Sasl2FeatureNegotiator
-    implements Bind2FeatureNegotiator {
-  CarbonsNegotiator() : super(0, false, carbonsXmlns, carbonsNegotiator);
+class CarbonsNegotiator extends Bind2FeatureNegotiator {
+  CarbonsNegotiator() : super(0, carbonsXmlns, carbonsNegotiator);
 
   /// Flag indicating whether we requested to enable carbons inline (true) or not
   /// (false).
@@ -214,19 +210,12 @@ class CarbonsNegotiator extends Sasl2FeatureNegotiator
   final Logger _log = Logger('CarbonsNegotiator');
 
   @override
-  bool canInlineFeature(List<XMLNode> features) => true;
-
-  @override
-  Future<List<XMLNode>> onSasl2FeaturesReceived(XMLNode sasl2Features) async {
-    return [];
+  Future<void> onBind2Success(XMLNode response) async {
+    if (!_requestedEnablement) {
+      return;
     }
 
-  @override
-  Future<Result<bool, NegotiatorError>> onSasl2Success(XMLNode response) async {
-    if (_requestedEnablement) {
-      final enabled = response
-          .firstTag('bound', xmlns: bind2Xmlns)
-          ?.firstTag('enabled', xmlns: carbonsXmlns);
+    final enabled = response.firstTag('enabled', xmlns: carbonsXmlns);
     final cm = attributes.getManagerById<CarbonsManager>(carbonsManager)!;
     if (enabled != null) {
       _log.finest('Successfully enabled Message Carbons inline');
@@ -237,19 +226,10 @@ class CarbonsNegotiator extends Sasl2FeatureNegotiator
     }
   }
 
-    return const Result(true);
-  }
-
-  @override
-  Future<Result<NegotiatorState, NegotiatorError>> negotiate(
-    XMLNode nonza,
-  ) async {
-    return const Result(NegotiatorState.done);
-  }
-
   @override
   Future<List<XMLNode>> onBind2FeaturesReceived(
-      List<String> bind2Features) async {
+    List<String> bind2Features,
+  ) async {
     if (!bind2Features.contains(carbonsXmlns)) {
       return [];
     }
@@ -263,16 +243,6 @@ class CarbonsNegotiator extends Sasl2FeatureNegotiator
     ];
   }
 
-  @override
-  Future<void> postRegisterCallback() async {
-    attributes
-        .getNegotiatorById<Sasl2Negotiator>(sasl2Negotiator)
-        ?.registerNegotiator(this);
-    attributes
-        .getNegotiatorById<Bind2Negotiator>(bind2Negotiator)
-        ?.registerNegotiator(this);
-  }
-
   @override
   void reset() {
     _requestedEnablement = false;

packages/moxxmpp/lib/src/xeps/xep_0352.dart

@@ -25,7 +25,7 @@ class CSIInactiveNonza extends XMLNode {
 
 /// A Stub negotiator that is just for "intercepting" the stream feature.
 class CSINegotiator extends XmppFeatureNegotiatorBase
-    implements Bind2FeatureNegotiator {
+    implements Bind2FeatureNegotiatorInterface {
   CSINegotiator() : super(11, false, csiXmlns, csiNegotiator);
 
   /// True if CSI is supported. False otherwise.
@@ -50,12 +50,16 @@ class CSINegotiator extends XmppFeatureNegotiatorBase
       return [];
     }
 
+    _supported = true;
     final active = attributes.getManagerById<CSIManager>(csiManager)!.isActive;
     return [
       if (active) CSIActiveNonza() else CSIInactiveNonza(),
     ];
   }
 
+  @override
+  Future<void> onBind2Success(XMLNode response) async {}
+
   @override
   void reset() {
     _supported = false;

packages/moxxmpp/lib/src/xeps/xep_0386.dart

@@ -1,4 +1,5 @@
 import 'package:collection/collection.dart';
+import 'package:meta/meta.dart';
 import 'package:moxxmpp/src/namespaces.dart';
 import 'package:moxxmpp/src/negotiators/namespaces.dart';
 import 'package:moxxmpp/src/negotiators/negotiator.dart';
@@ -9,10 +10,43 @@ import 'package:moxxmpp/src/types/result.dart';
 /// An interface that allows registering against Bind2's feature list in order to
 /// negotiate features inline with Bind2.
 // ignore: one_member_abstracts
-abstract class Bind2FeatureNegotiator {
+abstract class Bind2FeatureNegotiatorInterface {
   /// Called by the Bind2 negotiator when Bind2 features are received. The returned
   /// [XMLNode]s are added to Bind2's bind request.
   Future<List<XMLNode>> onBind2FeaturesReceived(List<String> bind2Features);
+
+  /// Called by the Bind2 negotiator when Bind2 results are received.
+  Future<void> onBind2Success(XMLNode result);
+}
+
+/// A class that allows for simple negotiators that only registers itself against
+/// the Bind2 negotiator. You only have to implement the functions required by
+/// [Bind2FeatureNegotiatorInterface].
+abstract class Bind2FeatureNegotiator extends XmppFeatureNegotiatorBase
+    implements Bind2FeatureNegotiatorInterface {
+  Bind2FeatureNegotiator(
+    int priority,
+    String negotiatingXmlns,
+    String id,
+  ) : super(priority, false, negotiatingXmlns, id);
+
+  @override
+  bool matchesFeature(List<XMLNode> features) => false;
+
+  @override
+  Future<Result<NegotiatorState, NegotiatorError>> negotiate(
+    XMLNode nonza,
+  ) async {
+    return const Result(NegotiatorState.done);
+  }
+
+  @mustCallSuper
+  @override
+  Future<void> postRegisterCallback() async {
+    attributes
+        .getNegotiatorById<Bind2Negotiator>(bind2Negotiator)!
+        .registerNegotiator(this);
+  }
 }
 
 /// A negotiator implementing XEP-0386. This negotiator is useless on its own
@@ -21,15 +55,15 @@ class Bind2Negotiator extends Sasl2FeatureNegotiator {
   Bind2Negotiator() : super(0, false, bind2Xmlns, bind2Negotiator);
 
   /// A list of negotiators that can work with Bind2.
-  final List<Bind2FeatureNegotiator> _negotiators =
-      List<Bind2FeatureNegotiator>.empty(growable: true);
+  final List<Bind2FeatureNegotiatorInterface> _negotiators =
+      List<Bind2FeatureNegotiatorInterface>.empty(growable: true);
 
   /// A tag to sent to the server when requesting Bind2.
   String? tag;
 
   /// Register [negotiator] against the Bind2 negotiator to append data to the Bind2
   /// negotiation.
-  void registerNegotiator(Bind2FeatureNegotiator negotiator) {
+  void registerNegotiator(Bind2FeatureNegotiatorInterface negotiator) {
     _negotiators.add(negotiator);
   }
 
@@ -87,8 +121,14 @@ class Bind2Negotiator extends Sasl2FeatureNegotiator {
 
   @override
   Future<Result<bool, NegotiatorError>> onSasl2Success(XMLNode response) async {
-    attributes.removeNegotiatingFeature(bindXmlns);
+    final bound = response.firstTag('bound', xmlns: bind2Xmlns);
+    if (bound != null) {
+      for (final negotiator in _negotiators) {
+        await negotiator.onBind2Success(bound);
+      }
+    }
 
+    attributes.removeNegotiatingFeature(bindXmlns);
     return const Result(true);
   }
 

packages/moxxmpp/test/xeps/xep_0280_test.dart

@@ -141,6 +141,8 @@ void main() {
     expect(result.isType<NegotiatorError>(), false);
     expect(conn.resource, 'test-resource');
     expect(
-        conn.getManagerById<CarbonsManager>(carbonsManager)!.isEnabled, true);
+      conn.getManagerById<CarbonsManager>(carbonsManager)!.isEnabled,
+      true,
+    );
   });
 }

packages/moxxmpp/test/xeps/xep_0352_test.dart

@@ -204,5 +204,9 @@ void main() {
     );
     expect(result.isType<NegotiatorError>(), false);
     expect(fakeSocket.getState(), 2);
+    expect(
+      conn.getNegotiatorById<CSINegotiator>(csiNegotiator)!.isSupported,
+      true,
+    );
   });
 }