xmpp-parsers: Move the Stanza type from tokio-xmpp

It doesn’t come with the ensure_id() method, but otherwise this is a
much better location for it.

parsers/ChangeLog

@@ -24,6 +24,8 @@ XXXX-YY-ZZ RELEASER <admin@example.com>
           not be rejected by xmpp-parsers by default anymore. The `pedantic`
           feature can be used to opt into the previous default behaviour.
     * Improvements:
+        - Take the Stanza type from tokio-xmpp, it’s an enum which can wrap
+          Message, Presence and Iq.
         - Make Priority’s inner i8 pub, which had been broken since the
           conversion to xso. (!632)
         - ibr::LegacyQuery now implements Default, allowing users to more

parsers/src/lib.rs

@@ -64,6 +64,8 @@ pub mod presence;
 /// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
 pub mod sasl;
 /// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
+pub mod stanza;
+/// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
 pub mod stanza_error;
 /// RFC 6120: Extensible Messaging and Presence Protocol (XMPP): Core
 pub mod starttls;

parsers/src/stanza.rs

@@ -0,0 +1,81 @@
+// Copyright (c) 2024 Jonas Schäfer <jonas@zombofant.net>
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+use xso::{AsXml, FromXml};
+
+use crate::{iq::Iq, message::Message, presence::Presence};
+
+/// A stanza sent/received over the stream.
+///
+/// WARNING: do not add variants to this enum! Adding variants which refer
+/// to anything but [`Iq`], [`Message`] or [`Presence`] stanzas will cause the
+/// stream management counters to be off.
+#[derive(FromXml, AsXml, Debug, PartialEq)]
+#[xml()]
+pub enum Stanza {
+    /// IQ stanza
+    #[xml(transparent)]
+    Iq(Iq),
+
+    /// Message stanza
+    #[xml(transparent)]
+    Message(Message),
+
+    /// Presence stanza
+    #[xml(transparent)]
+    Presence(Presence),
+}
+
+impl From<Iq> for Stanza {
+    fn from(other: Iq) -> Self {
+        Self::Iq(other)
+    }
+}
+
+impl From<Presence> for Stanza {
+    fn from(other: Presence) -> Self {
+        Self::Presence(other)
+    }
+}
+
+impl From<Message> for Stanza {
+    fn from(other: Message) -> Self {
+        Self::Message(other)
+    }
+}
+
+impl TryFrom<Stanza> for Message {
+    type Error = Stanza;
+
+    fn try_from(other: Stanza) -> Result<Self, Stanza> {
+        match other {
+            Stanza::Message(st) => Ok(st),
+            other => Err(other),
+        }
+    }
+}
+
+impl TryFrom<Stanza> for Presence {
+    type Error = Stanza;
+
+    fn try_from(other: Stanza) -> Result<Self, Stanza> {
+        match other {
+            Stanza::Presence(st) => Ok(st),
+            other => Err(other),
+        }
+    }
+}
+
+impl TryFrom<Stanza> for Iq {
+    type Error = Stanza;
+
+    fn try_from(other: Stanza) -> Result<Self, Stanza> {
+        match other {
+            Stanza::Iq(st) => Ok(st),
+            other => Err(other),
+        }
+    }
+}