From b2ba646fd4e50589fbe12a8e2faf56413ee7e109 Mon Sep 17 00:00:00 2001
From: famfo <famfo@famfo.xyz>
Date: Tue, 6 Feb 2024 00:49:37 +0100
Subject: [PATCH] Implement empty before for QuerySet

---
 parsers/src/rsm.rs | 26 ++++++++++++++++++++++----
 1 file changed, 22 insertions(+), 4 deletions(-)

diff --git a/parsers/src/rsm.rs b/parsers/src/rsm.rs
index 9eb11dd0..af3aa744 100644
--- a/parsers/src/rsm.rs
+++ b/parsers/src/rsm.rs
@@ -78,10 +78,13 @@ impl From<SetQuery> for Element {
                 set.after
                     .map(|after| Element::builder("after", ns::RSM).append(after)),
             )
-            .append_all(
-                set.before
-                    .map(|before| Element::builder("before", ns::RSM).append(before)),
-            )
+            .append_all(set.before.map(|before| {
+                let mut builder = Element::builder("before", ns::RSM);
+                if !before.is_empty() {
+                    builder = builder.append(before);
+                }
+                builder
+            }))
             .append_all(
                 set.index
                     .map(|index| Element::builder("index", ns::RSM).append(format!("{}", index))),
@@ -278,6 +281,21 @@ mod tests {
         assert_eq!(elem, elem2);
     }
 
+    #[test]
+    fn test_serialise_empty_before() {
+        let elem: Element = "<set xmlns='http://jabber.org/protocol/rsm'><before/></set>"
+            .parse()
+            .unwrap();
+        let rsm = SetQuery {
+            max: None,
+            after: None,
+            before: Some("".into()),
+            index: None,
+        };
+        let elem2 = rsm.into();
+        assert_eq!(elem, elem2);
+    }
+
     #[test]
     fn test_first_index() {
         let elem: Element =