feat(xep): Also potentially return "generic" stanza errors

packages/moxxmpp/CHANGELOG.md

@@ -17,6 +17,7 @@
 - **BREAKING**: Removed `PresenceReceivedEvent`. Use a manager registering handlers with priority greater than `[PresenceManager.presenceHandlerPriority]` instead.
 - **BREAKING**: `ChatState.toString()` is now `ChatState.toName()`
 - **BREAKING**: Overriding `BaseOmemoManager` is no longer required. `OmemoManager` now takes callback methods instead.
+- Removed `ErrorResponseDiscoError` from the possible XEP-0030 errors.
 
 ## 0.3.1
 

packages/moxxmpp/lib/src/stanza.dart

@@ -47,28 +47,57 @@ class StanzaDetails {
   final TypedMap<StanzaHandlerExtension>? postSendExtensions;
 }
 
-/// A simple description of the <error /> element that may be inside a stanza
-class StanzaError {
-  StanzaError(this.type, this.error);
-  String type;
-  String error;
+/// A general error type for errors.
+abstract class StanzaError {
+  static StanzaError? fromXMLNode(XMLNode node) {
+    final error = node.firstTag('error');
+    if (error == null) {
+      return null;
+    }
+
+    final specificError = error.firstTagByXmlns(fullStanzaXmlns);
+    if (specificError == null) {
+      return UnknownStanzaError();
+    }
+
+    switch (specificError.tag) {
+      case RemoteServerNotFoundError.tag:
+        return RemoteServerNotFoundError();
+      case RemoteServerTimeoutError.tag:
+        return RemoteServerTimeoutError();
+      case ServiceUnavailableError.tag:
+        return ServiceUnavailableError();
+    }
+
+    return UnknownStanzaError();
+  }
 
-  /// Returns a StanzaError if [stanza] contains a <error /> element. If not, returns
-  /// null.
   static StanzaError? fromStanza(Stanza stanza) {
-    final error = stanza.firstTag('error');
-    if (error == null) return null;
-
-    final stanzaError = error.firstTagByXmlns(fullStanzaXmlns);
-    if (stanzaError == null) return null;
-
-    return StanzaError(
-      error.attributes['type']! as String,
-      stanzaError.tag,
-    );
+    return fromXMLNode(stanza);
   }
 }
 
+/// Recipient does not provide a given service.
+/// https://xmpp.org/rfcs/rfc6120.html#stanzas-error-conditions-service-unavailable
+class ServiceUnavailableError extends StanzaError {
+  static const tag = 'service-unavailable';
+}
+
+/// Could not connect to the remote server.
+/// https://xmpp.org/rfcs/rfc6120.html#stanzas-error-conditions-remote-server-not-found
+class RemoteServerNotFoundError extends StanzaError {
+  static const tag = 'remote-server-not-found';
+}
+
+/// The connection to the remote server timed out.
+/// https://xmpp.org/rfcs/rfc6120.html#stanzas-error-conditions-remote-server-timeout
+class RemoteServerTimeoutError extends StanzaError {
+  static const tag = 'remote-server-timeout';
+}
+
+/// An unknown error.
+class UnknownStanzaError extends StanzaError {}
+
 class Stanza extends XMLNode {
   // ignore: use_super_parameters
   Stanza({

packages/moxxmpp/lib/src/xeps/xep_0030/errors.dart

@@ -1,7 +1,10 @@
-abstract class DiscoError {}
+import 'package:moxxmpp/src/stanza.dart';
 
+/// Base type for disco-related errors.
+abstract class DiscoError extends StanzaError {}
+
+/// An unspecified error that is not covered by another [DiscoError].
 class UnknownDiscoError extends DiscoError {}
 
+/// The received disco response is invalid in some shape or form.
 class InvalidResponseDiscoError extends DiscoError {}
-
-class ErrorResponseDiscoError extends DiscoError {}

packages/moxxmpp/lib/src/xeps/xep_0030/xep_0030.dart

@@ -44,11 +44,11 @@ class DiscoManager extends XmppManagerBase {
   final Map<DiscoCacheKey, DiscoInfo> _discoInfoCache = {};
 
   /// The tracker for tracking disco#info queries that are in flight.
-  final WaitForTracker<DiscoCacheKey, Result<DiscoError, DiscoInfo>>
+  final WaitForTracker<DiscoCacheKey, Result<StanzaError, DiscoInfo>>
       _discoInfoTracker = WaitForTracker();
 
   /// The tracker for tracking disco#info queries that are in flight.
-  final WaitForTracker<DiscoCacheKey, Result<DiscoError, List<DiscoItem>>>
+  final WaitForTracker<DiscoCacheKey, Result<StanzaError, List<DiscoItem>>>
       _discoItemsTracker = WaitForTracker();
 
   /// Cache lock
@@ -67,7 +67,7 @@ class DiscoManager extends XmppManagerBase {
   List<String> get features => _features;
 
   @visibleForTesting
-  WaitForTracker<DiscoCacheKey, Result<DiscoError, DiscoInfo>>
+  WaitForTracker<DiscoCacheKey, Result<StanzaError, DiscoInfo>>
       get infoTracker => _discoInfoTracker;
 
   @override
@@ -231,7 +231,7 @@ class DiscoManager extends XmppManagerBase {
 
   Future<void> _exitDiscoInfoCriticalSection(
     DiscoCacheKey key,
-    Result<DiscoError, DiscoInfo> result,
+    Result<StanzaError, DiscoInfo> result,
     bool shouldCache,
   ) async {
     await _cacheLock.synchronized(() async {
@@ -252,7 +252,7 @@ class DiscoManager extends XmppManagerBase {
   ///
   /// [shouldCache] indicates whether the successful result of the disco#info query
   /// should be cached (true) or not(false).
-  Future<Result<DiscoError, DiscoInfo>> discoInfoQuery(
+  Future<Result<StanzaError, DiscoInfo>> discoInfoQuery(
     JID entity, {
     String? node,
     bool shouldEncrypt = false,
@@ -263,7 +263,7 @@ class DiscoManager extends XmppManagerBase {
     final ecm = getAttributes()
         .getManagerById<EntityCapabilitiesManager>(entityCapabilitiesManager);
     final ffuture = await _cacheLock
-        .synchronized<Future<Future<Result<DiscoError, DiscoInfo>>?>?>(
+        .synchronized<Future<Future<Result<StanzaError, DiscoInfo>>?>?>(
             () async {
       // Check if we already know what the JID supports
       if (_discoInfoCache.containsKey(cacheKey)) {
@@ -297,16 +297,18 @@ class DiscoManager extends XmppManagerBase {
         shouldEncrypt: shouldEncrypt,
       ),
     ))!;
-    final query = stanza.firstTag('query');
-    if (query == null) {
-      final result = Result<DiscoError, DiscoInfo>(InvalidResponseDiscoError());
+
+    // Error handling
+    if (stanza.attributes['type'] == 'error') {
+      final result =
+          Result<StanzaError, DiscoInfo>(StanzaError.fromXMLNode(stanza));
       await _exitDiscoInfoCriticalSection(cacheKey, result, shouldCache);
       return result;
     }
 
-    if (stanza.attributes['type'] == 'error') {
-      //final error = stanza.firstTag('error');
-      final result = Result<DiscoError, DiscoInfo>(ErrorResponseDiscoError());
+    final query = stanza.firstTag('query');
+    if (query == null) {
+      final result = Result<DiscoError, DiscoInfo>(InvalidResponseDiscoError());
       await _exitDiscoInfoCriticalSection(cacheKey, result, shouldCache);
       return result;
     }
@@ -322,7 +324,7 @@ class DiscoManager extends XmppManagerBase {
   }
 
   /// Sends a disco items query to the (full) jid [entity], optionally with node=[node].
-  Future<Result<DiscoError, List<DiscoItem>>> discoItemsQuery(
+  Future<Result<StanzaError, List<DiscoItem>>> discoItemsQuery(
     JID entity, {
     String? node,
     bool shouldEncrypt = false,
@@ -340,19 +342,18 @@ class DiscoManager extends XmppManagerBase {
       ),
     ))!;
 
-    final query = stanza.firstTag('query');
-    if (query == null) {
+    // Error handling
+    if (stanza.attributes['type'] == 'error') {
       final result =
-          Result<DiscoError, List<DiscoItem>>(InvalidResponseDiscoError());
+          Result<StanzaError, List<DiscoItem>>(StanzaError.fromXMLNode(stanza));
       await _discoItemsTracker.resolve(key, result);
       return result;
     }
 
-    if (stanza.attributes['type'] == 'error') {
-      //final error = stanza.firstTag('error');
-      //print("Disco Items error: " + error.toXml());
+    final query = stanza.firstTag('query');
+    if (query == null) {
       final result =
-          Result<DiscoError, List<DiscoItem>>(ErrorResponseDiscoError());
+          Result<DiscoError, List<DiscoItem>>(InvalidResponseDiscoError());
       await _discoItemsTracker.resolve(key, result);
       return result;
     }
@@ -419,7 +420,7 @@ class DiscoManager extends XmppManagerBase {
   /// [entity] supports the disco feature [feature]. If not, returns false.
   Future<bool> supportsFeature(JID entity, String feature) async {
     final info = await discoInfoQuery(entity);
-    if (info.isType<DiscoError>()) return false;
+    if (info.isType<StanzaError>()) return false;
 
     return info.get<DiscoInfo>().features.contains(feature);
   }