xmpp-parsers: Remove Feature from disco#info

This was just a newtype for a String, but in general using it was harder
than without it.  This simplifies the public API.

parsers/ChangeLog

@@ -12,6 +12,8 @@ XXXX-YY-ZZ RELEASER <admin@example.com>
           used in XMPP.
         - Remove the unnecessary SaslMechanisms struct, to directly extract
           SASL mechanisms in a Vec<String> in StreamFeatures.
+        - The type of disco::DiscoInfoResult::features changed from
+          Vec<Feature> to Vec<String>, this lets us remove Feature as well.
         - bind::BindFeature::required is now a bool, thanks to xso’s flag.
         - jingle_rtp::Description::rtcp_mux is now a bool flag too.
         - stream_limits::Limits now extract directly to NonZeroU32.

parsers/src/caps.rs

@@ -7,7 +7,7 @@
 use xso::{AsXml, FromXml};
 
 use crate::data_forms::DataForm;
-use crate::disco::{DiscoInfoQuery, DiscoInfoResult, Feature, Identity};
+use crate::disco::{DiscoInfoQuery, DiscoInfoResult, Identity};
 use crate::hashes::{Algo, Hash};
 use crate::ns;
 use crate::presence::PresencePayload;
@@ -79,8 +79,8 @@ fn compute_items<T, F: Fn(&T) -> Vec<u8>>(things: &[T], encode: F) -> Vec<u8> {
     string
 }
 
-fn compute_features(features: &[Feature]) -> Vec<u8> {
-    compute_items(features, |feature| compute_item(&feature.var))
+fn compute_features(features: &[String]) -> Vec<u8> {
+    compute_items(features, |feature| compute_item(&feature))
 }
 
 fn compute_identities(identities: &[Identity]) -> Vec<u8> {

parsers/src/disco.rs

@@ -26,22 +26,6 @@ pub struct DiscoInfoQuery {
 
 impl IqGetPayload for DiscoInfoQuery {}
 
-/// Structure representing a `<feature xmlns='http://jabber.org/protocol/disco#info'/>` element.
-#[derive(FromXml, AsXml, Debug, Clone, PartialEq, Eq, Hash)]
-#[xml(namespace = ns::DISCO_INFO, name = "feature")]
-pub struct Feature {
-    /// Namespace of the feature we want to represent.
-    #[xml(attribute)]
-    pub var: String,
-}
-
-impl Feature {
-    /// Create a new `<feature/>` with the according `@var`.
-    pub fn new<S: Into<String>>(var: S) -> Feature {
-        Feature { var: var.into() }
-    }
-}
-
 /// Structure representing an `<identity xmlns='http://jabber.org/protocol/disco#info'/>` element.
 #[derive(FromXml, AsXml, Debug, Clone, PartialEq, Eq, Hash)]
 #[xml(namespace = ns::DISCO_INFO, name = "identity")]
@@ -113,8 +97,8 @@ pub struct DiscoInfoResult {
     pub identities: Vec<Identity>,
 
     /// List of features supported by this entity.
-    #[xml(child(n = ..))]
-    pub features: Vec<Feature>,
+    #[xml(extract(n = .., name = "feature", fields(attribute(name = "var", type_ = String))))]
+    pub features: Vec<String>,
 
     /// List of extensions reported by this entity.
     #[xml(child(n = ..))]
@@ -192,7 +176,6 @@ mod tests {
     #[test]
     fn test_size() {
         assert_size!(Identity, 48);
-        assert_size!(Feature, 12);
         assert_size!(DiscoInfoQuery, 12);
         assert_size!(DiscoInfoResult, 48);
 
@@ -205,7 +188,6 @@ mod tests {
     #[test]
     fn test_size() {
         assert_size!(Identity, 96);
-        assert_size!(Feature, 24);
         assert_size!(DiscoInfoQuery, 24);
         assert_size!(DiscoInfoResult, 96);
 
@@ -325,9 +307,11 @@ mod tests {
             FromElementError::Invalid(Error::Other(string)) => string,
             _ => panic!(),
         };
+        // TODO: Make xso generate a better error message, with s/unnamed field 0/'var'/ for
+        // instance.
         assert_eq!(
             message,
-            "Required attribute field 'var' on Feature element missing."
+            "Required attribute unnamed field 0 on extraction for field 'features' in DiscoInfoResult element missing."
         );
     }
 

parsers/src/ecaps2.rs

@@ -7,7 +7,7 @@
 use xso::{AsXml, FromXml};
 
 use crate::data_forms::DataForm;
-use crate::disco::{DiscoInfoQuery, DiscoInfoResult, Feature, Identity};
+use crate::disco::{DiscoInfoQuery, DiscoInfoResult, Identity};
 use crate::hashes::{Algo, Hash};
 use crate::ns;
 use crate::presence::PresencePayload;
@@ -64,8 +64,8 @@ fn compute_items<'x, T: 'x, I: IntoIterator<Item = &'x T>, F: Fn(&'x T) -> Vec<u
     string
 }
 
-fn compute_features(features: &[Feature]) -> Vec<u8> {
-    compute_items(features, 0x1c, |feature| compute_item(&feature.var))
+fn compute_features(features: &[String]) -> Vec<u8> {
+    compute_items(features, 0x1c, |feature| compute_item(&feature))
 }
 
 fn compute_identities(identities: &[Identity]) -> Vec<u8> {

tokio-xmpp/examples/download_avatars.rs

@@ -9,7 +9,7 @@ use tokio_xmpp::{Client, Stanza};
 use xmpp_parsers::{
     avatar::{Data as AvatarData, Metadata as AvatarMetadata},
     caps::{compute_disco, hash_caps, Caps},
-    disco::{DiscoInfoQuery, DiscoInfoResult, Feature, Identity},
+    disco::{DiscoInfoQuery, DiscoInfoResult, Identity},
     hashes::Algo,
     iq::Iq,
     jid::{BareJid, Jid},
@@ -185,8 +185,8 @@ fn make_error(
 fn make_disco() -> DiscoInfoResult {
     let identities = vec![Identity::new("client", "bot", "en", "tokio-xmpp")];
     let features = vec![
-        Feature::new(ns::DISCO_INFO),
-        Feature::new(format!("{}+notify", ns::AVATAR_METADATA)),
+        String::from(ns::DISCO_INFO),
+        format!("{}+notify", ns::AVATAR_METADATA),
     ];
     DiscoInfoResult {
         node: None,

xmpp/src/builder.rs

@@ -11,7 +11,7 @@ use crate::{
     Agent, ClientFeature, ClientType, Config, RoomNick,
     jid::{BareJid, Jid, ResourceRef},
     parsers::{
-        disco::{DiscoInfoResult, Feature, Identity},
+        disco::{DiscoInfoResult, Identity},
         ns,
     },
     tokio_xmpp::{Client as TokioXmppClient, connect::ServerConnector, xmlstream::Timeouts},
@@ -107,15 +107,15 @@ impl<C: ServerConnector> ClientBuilder<'_, C> {
             "en",
             self.config.disco.1.to_string(),
         )];
-        let mut features = vec![Feature::new(ns::DISCO_INFO)];
+        let mut features = vec![String::from(ns::DISCO_INFO)];
         #[cfg(feature = "avatars")]
         {
             if self.features.contains(&ClientFeature::Avatars) {
-                features.push(Feature::new(format!("{}+notify", ns::AVATAR_METADATA)));
+                features.push(format!("{}+notify", ns::AVATAR_METADATA));
             }
         }
         if self.features.contains(&ClientFeature::JoinRooms) {
-            features.push(Feature::new(format!("{}+notify", ns::BOOKMARKS2)));
+            features.push(format!("{}+notify", ns::BOOKMARKS2));
         }
         DiscoInfoResult {
             node: None,

xmpp/src/disco/mod.rs

@@ -25,12 +25,9 @@ pub async fn handle_disco_info_result(agent: &mut Agent, disco: DiscoInfoResult,
         // Trigger bookmarks query
         // TODO: only send this when the JoinRooms feature is enabled.
         agent.awaiting_disco_bookmarks_type = false;
-        let mut perform_bookmarks2 = false;
-        for feature in disco.features {
-            if feature.var == "urn:xmpp:bookmarks:1#compat" {
-                perform_bookmarks2 = true;
-            }
-        }
+        let perform_bookmarks2 = disco
+            .features
+            .contains(&String::from("urn:xmpp:bookmarks:1#compat"));
 
         if perform_bookmarks2 {
             // XEP-0402 bookmarks (modern)