feat(xep): Allow inlining CSI

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

@@ -5,6 +5,7 @@ import 'package:moxxmpp/src/negotiators/namespaces.dart';
 import 'package:moxxmpp/src/negotiators/negotiator.dart';
 import 'package:moxxmpp/src/stringxml.dart';
 import 'package:moxxmpp/src/types/result.dart';
+import 'package:moxxmpp/src/xeps/xep_0386.dart';
 
 class CSIActiveNonza extends XMLNode {
   CSIActiveNonza()
@@ -23,7 +24,8 @@ class CSIInactiveNonza extends XMLNode {
 }
 
 /// A Stub negotiator that is just for "intercepting" the stream feature.
-class CSINegotiator extends XmppFeatureNegotiatorBase {
+class CSINegotiator extends XmppFeatureNegotiatorBase
+    implements Bind2FeatureNegotiator {
   CSINegotiator() : super(11, false, csiXmlns, csiNegotiator);
 
   /// True if CSI is supported. False otherwise.
@@ -40,19 +42,43 @@ class CSINegotiator extends XmppFeatureNegotiatorBase {
     return const Result(NegotiatorState.done);
   }
 
+  @override
+  Future<List<XMLNode>> onBind2FeaturesReceived(
+    List<String> bind2Features,
+  ) async {
+    if (!bind2Features.contains(csiXmlns)) {
+      return [];
+    }
+
+    final active = attributes.getManagerById<CSIManager>(csiManager)!.isActive;
+    return [
+      if (active) CSIActiveNonza() else CSIInactiveNonza(),
+    ];
+  }
+
   @override
   void reset() {
     _supported = false;
 
     super.reset();
   }
+
+  @override
+  Future<void> postRegisterCallback() async {
+    attributes
+        .getNegotiatorById<Bind2Negotiator>(bind2Negotiator)
+        ?.registerNegotiator(this);
+  }
 }
 
 /// The manager requires a CSINegotiator to be registered as a feature negotiator.
 class CSIManager extends XmppManagerBase {
   CSIManager() : super(csiManager);
 
+  /// Flag indicating whether the application is currently active and the CSI
+  /// traffic optimisation should be disabled (true).
   bool _isActive = true;
+  bool get isActive => _isActive;
 
   @override
   Future<bool> isSupported() async {
@@ -71,23 +97,31 @@ class CSIManager extends XmppManagerBase {
     }
   }
 
-  /// Tells the server to top optimizing traffic
+  /// Tells the server to stop optimizing traffic.
-  Future<void> setActive() async {
+  /// If [sendNonza] is false, then no nonza is sent. This is useful
+  /// for setting up the CSI manager for Bind2.
+  Future<void> setActive({bool sendNonza = true}) async {
     _isActive = true;
 
-    final attrs = getAttributes();
+    if (sendNonza) {
-    if (await isSupported()) {
+      final attrs = getAttributes();
-      attrs.sendNonza(CSIActiveNonza());
+      if (await isSupported()) {
+        attrs.sendNonza(CSIActiveNonza());
+      }
     }
   }
 
   /// Tells the server to optimize traffic following XEP-0352
-  Future<void> setInactive() async {
+  /// If [sendNonza] is false, then no nonza is sent. This is useful
+  /// for setting up the CSI manager for Bind2.
+  Future<void> setInactive({bool sendNonza = true}) async {
     _isActive = false;
 
-    final attrs = getAttributes();
+    if (sendNonza) {
-    if (await isSupported()) {
+      final attrs = getAttributes();
-      attrs.sendNonza(CSIInactiveNonza());
+      if (await isSupported()) {
+        attrs.sendNonza(CSIInactiveNonza());
+      }
     }
   }
 }

packages/moxxmpp/test/xeps/xep_0352_test.dart

@@ -1,5 +1,6 @@
 import 'package:moxxmpp/moxxmpp.dart';
 import 'package:test/test.dart';
+import '../helpers/logging.dart';
 import '../helpers/xmpp.dart';
 
 class MockedCSINegotiator extends CSINegotiator {
@@ -28,6 +29,8 @@ T? getUnsupportedCSINegotiator<T extends XmppFeatureNegotiatorBase>(String id) {
 }
 
 void main() {
+  initLogger();
+
   group('Test the XEP-0352 implementation', () {
     test('Test setting the CSI state when CSI is unsupported', () {
       var nonzaSent = false;
@@ -111,4 +114,95 @@ void main() {
         ..setInactive();
     });
   });
+
+  test('Test CSI with Bind2', () async {
+    final fakeSocket = StubTCPSocket([
+      StringExpectation(
+        "<stream:stream xmlns='jabber:client' version='1.0' xmlns:stream='http://etherx.jabber.org/streams' to='test.server' xml:lang='en'>",
+        '''
+<stream:stream
+    xmlns="jabber:client"
+    version="1.0"
+    xmlns:stream="http://etherx.jabber.org/streams"
+    from="test.server"
+    xml:lang="en">
+  <stream:features xmlns="http://etherx.jabber.org/streams">
+    <mechanisms xmlns="urn:ietf:params:xml:ns:xmpp-sasl">
+      <mechanism>PLAIN</mechanism>
+    </mechanisms>
+    <authentication xmlns='urn:xmpp:sasl:2'>
+      <mechanism>PLAIN</mechanism>
+      <inline>
+        <bind xmlns="urn:xmpp:bind:0">
+          <inline>
+            <feature var="urn:xmpp:csi:0" />
+          </inline>
+        </bind>
+      </inline>
+    </authentication>
+    <bind xmlns="urn:ietf:params:xml:ns:xmpp-bind">
+      <required/>
+    </bind>
+  </stream:features>''',
+      ),
+      StanzaExpectation(
+        '''
+<authenticate xmlns='urn:xmpp:sasl:2' mechanism='PLAIN'>
+  <user-agent id='d4565fa7-4d72-4749-b3d3-740edbf87770'>
+    <software>moxxmpp</software>
+    <device>PapaTutuWawa's awesome device</device>
+  </user-agent>
+  <initial-response>AHBvbHlub21kaXZpc2lvbgBhYWFh</initial-response>
+  <bind xmlns='urn:xmpp:bind:0'>
+    <inactive xmlns='urn:xmpp:csi:0' />
+  </bind>
+</authenticate>''',
+        '''
+<success xmlns='urn:xmpp:sasl:2'>
+  <authorization-identifier>polynomdivision@test.server/test-resource</authorization-identifier>
+</success>
+        ''',
+      ),
+    ]);
+    final conn = XmppConnection(
+      TestingReconnectionPolicy(),
+      AlwaysConnectedConnectivityManager(),
+      fakeSocket,
+    )..setConnectionSettings(
+        ConnectionSettings(
+          jid: JID.fromString('polynomdivision@test.server'),
+          password: 'aaaa',
+          useDirectTLS: true,
+        ),
+      );
+    final csi = CSIManager();
+    await csi.setInactive(sendNonza: false);
+    await conn.registerManagers([
+      RosterManager(TestingRosterStateManager('', [])),
+      DiscoManager([]),
+      csi,
+    ]);
+    await conn.registerFeatureNegotiators([
+      SaslPlainNegotiator(),
+      ResourceBindingNegotiator(),
+      FASTSaslNegotiator(),
+      Bind2Negotiator(),
+      CSINegotiator(),
+      Sasl2Negotiator(
+        userAgent: const UserAgent(
+          id: 'd4565fa7-4d72-4749-b3d3-740edbf87770',
+          software: 'moxxmpp',
+          device: "PapaTutuWawa's awesome device",
+        ),
+      ),
+    ]);
+
+    final result = await conn.connect(
+      waitUntilLogin: true,
+      shouldReconnect: false,
+      enableReconnectOnSuccess: false,
+    );
+    expect(result.isType<NegotiatorError>(), false);
+    expect(fakeSocket.getState(), 2);
+  });
 }