xmpp-parsers: Convert Forwarded to xso

parsers/ChangeLog

@@ -19,6 +19,11 @@ XXXX-YY-ZZ RELEASER <admin@example.com>
         check whether a child element is present or not, as this is currently
         implemented in xso.  We might revert that change if we implement flag
         metas in xso before the next release.
+      - The forwarding module now hardcodes that its child is a message in the
+        jabber:client namespace.  It previously half-followed the schema, but
+        nothing so far uses it for anything but this message.  We can always
+        change it again once any other specification allows e.g. presences or
+        iqs.
     * New parsers/serialisers:
         - Stream Features (RFC 6120) (!400)
         - Extensible SASL Profile (XEP-0388)

parsers/src/carbons.rs

@@ -58,6 +58,7 @@ impl MessagePayload for Sent {}
 #[cfg(test)]
 mod tests {
     use super::*;
+    use jid::Jid;
     use minidom::Element;
 
     #[cfg(target_pointer_width = "32")]
@@ -104,7 +105,14 @@ mod tests {
             .parse()
             .unwrap();
         let received = Received::try_from(elem).unwrap();
-        assert!(received.forwarded.stanza.is_some());
+        assert_eq!(
+            received.forwarded.message.to.unwrap(),
+            Jid::new("juliet@capulet.example/balcony").unwrap()
+        );
+        assert_eq!(
+            received.forwarded.message.from.unwrap(),
+            Jid::new("romeo@montague.example/home").unwrap()
+        );
 
         let elem: Element = "<sent xmlns='urn:xmpp:carbons:2'>
   <forwarded xmlns='urn:xmpp:forward:0'>
@@ -116,7 +124,14 @@ mod tests {
             .parse()
             .unwrap();
         let sent = Sent::try_from(elem).unwrap();
-        assert!(sent.forwarded.stanza.is_some());
+        assert_eq!(
+            sent.forwarded.message.to.unwrap(),
+            Jid::new("juliet@capulet.example/balcony").unwrap()
+        );
+        assert_eq!(
+            sent.forwarded.message.from.unwrap(),
+            Jid::new("romeo@montague.example/home").unwrap()
+        );
     }
 
     #[test]

parsers/src/forwarding.rs

@@ -4,24 +4,29 @@
 // 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::delay::Delay;
 use crate::message::Message;
+use crate::ns;
 
-generate_element!(
-    /// Contains a forwarded stanza, either standalone or part of another
-    /// extension (such as carbons).
-    Forwarded, "forwarded", FORWARD,
-    children: [
-        /// When the stanza originally got sent.
-        delay: Option<Delay> = ("delay", DELAY) => Delay,
+/// Contains a forwarded stanza, either standalone or part of another
+/// extension (such as carbons).
+#[derive(FromXml, AsXml, Debug, Clone, PartialEq)]
+#[xml(namespace = ns::FORWARD, name = "forwarded")]
+pub struct Forwarded {
+    /// When the stanza originally got sent.
+    #[xml(child(default))]
+    pub delay: Option<Delay>,
 
-        // XXX: really?  Option?
-        /// The stanza being forwarded.
-        stanza: Option<Message> = ("message", DEFAULT_NS) => Message
-
-        // TODO: also handle the two other stanza possibilities.
-    ]
-);
+    /// The stanza being forwarded.
+    // The schema says that we should allow either a Message, Presence or Iq, in either
+    // jabber:client or jabber:server, but in the wild so far we’ve only seen Message being
+    // transmitted, so let’s hardcode that for now.  The schema also makes it optional, but so far
+    // it’s always present (or this wrapper is useless).
+    #[xml(child)]
+    pub message: Message,
+}
 
 #[cfg(test)]
 mod tests {
@@ -43,7 +48,10 @@ mod tests {
 
     #[test]
     fn test_simple() {
-        let elem: Element = "<forwarded xmlns='urn:xmpp:forward:0'/>".parse().unwrap();
+        let elem: Element =
+            "<forwarded xmlns='urn:xmpp:forward:0'><message xmlns='jabber:client'/></forwarded>"
+                .parse()
+                .unwrap();
         Forwarded::try_from(elem).unwrap();
     }
 
@@ -57,15 +65,15 @@ mod tests {
             FromElementError::Invalid(Error::Other(string)) => string,
             _ => panic!(),
         };
-        assert_eq!(message, "Unknown child in forwarded element.");
+        assert_eq!(message, "Unknown child in Forwarded element.");
     }
 
     #[test]
     fn test_serialise() {
-        let elem: Element = "<forwarded xmlns='urn:xmpp:forward:0'/>".parse().unwrap();
+        let elem: Element = "<forwarded xmlns='urn:xmpp:forward:0'><message xmlns='jabber:client' type='chat'/></forwarded>".parse().unwrap();
         let forwarded = Forwarded {
             delay: None,
-            stanza: None,
+            message: Message::new(None),
         };
         let elem2 = forwarded.into();
         assert_eq!(elem, elem2);
@@ -90,7 +98,7 @@ mod tests {
 
         let forwarded = Forwarded {
             delay: Some(delay),
-            stanza: Some(message),
+            message,
         };
 
         let serialized: Element = forwarded.into();
@@ -109,7 +117,7 @@ mod tests {
         };
         assert_eq!(
             message,
-            "Element forwarded must not have more than one delay child."
+            "Forwarded element must not have more than one child in field 'delay'."
         );
     }
 
@@ -125,7 +133,7 @@ mod tests {
         };
         assert_eq!(
             message,
-            "Element forwarded must not have more than one message child."
+            "Forwarded element must not have more than one child in field 'message'."
         );
     }
 }

parsers/src/message.rs

@@ -330,6 +330,28 @@ impl From<Message> for Element {
     }
 }
 
+impl ::xso::FromXml for Message {
+    type Builder = ::xso::minidom_compat::FromEventsViaElement<Message>;
+
+    fn from_events(
+        qname: ::xso::exports::rxml::QName,
+        attrs: ::xso::exports::rxml::AttrMap,
+    ) -> Result<Self::Builder, ::xso::error::FromEventsError> {
+        if qname.0 != crate::ns::DEFAULT_NS || qname.1 != "message" {
+            return Err(::xso::error::FromEventsError::Mismatch { name: qname, attrs });
+        }
+        Self::Builder::new(qname, attrs)
+    }
+}
+
+impl ::xso::AsXml for Message {
+    type ItemIter<'x> = ::xso::minidom_compat::AsItemsViaElement<'x>;
+
+    fn as_xml_iter(&self) -> Result<Self::ItemIter<'_>, ::xso::error::Error> {
+        ::xso::minidom_compat::AsItemsViaElement::new(self.clone())
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;