Fixed missing separator between booking items in mail summary. Fixes #5

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/backend/mail.rs

@@ -19,7 +19,6 @@ cfg_if! { if #[cfg(feature = "ssr")] {
     use lettre::transport::smtp::client::{Tls, TlsParameters};
     use lettre::transport::smtp::authentication::Credentials;
     use lettre::transport::smtp::extension::ClientId;
-    use std::ops::Add;
     use std::sync::mpsc::Sender;
     use std::sync::mpsc;
 
@@ -81,15 +80,12 @@ cfg_if! { if #[cfg(feature = "ssr")] {
         fn replace_body_vars(text: String, reservation: &ResSumWithItems) -> String {
             text
                 .replace("#date#", &reservation.summary.date.format("%d. %m. %Y").to_string())
-                .replace("#summary#", &{
-                    let mut sum = "".to_string();
-                    for p in &reservation.reservations {
-                        sum = sum.add(&format!("{}: {} - {}",
+                .replace("#summary#", &reservation.reservations.iter()
+                    .map(|p| format!("{}: {} - {}",
                         p.property.name,
-                            p.reservation.from.format("%H:%M").to_string(), p.reservation.to.format("%H:%M").to_string()));
-                    }
-                    sum
-                }
+                        p.reservation.from.format("%H:%M"), p.reservation.to.format("%H:%M")))
+                    .collect::<Vec<_>>()
+                    .join("\n")
             )
         }
 
@@ -267,19 +263,23 @@ mod tests {
     use chrono::{NaiveDate, NaiveTime};
     use crate::backend::data::{Reservation, ResProperty, ResWithProperty};
 
-    fn reservation() -> ResSumWithItems {
+    fn item(name: &str, from: (u32, u32), to: (u32, u32)) -> ResWithProperty {
         let mut property = ResProperty::default();
-        property.name = "Court 1".to_string();
+        property.name = name.to_string();
 
-        let mut reservation = ResSumWithItems::default();
-        reservation.summary.date = NaiveDate::from_ymd_opt(2030, 3, 5).unwrap();
-        reservation.reservations.push(ResWithProperty {
+        ResWithProperty {
             reservation: Reservation::new(
-                NaiveTime::from_hms_opt(8, 0, 0).unwrap(),
-                NaiveTime::from_hms_opt(9, 30, 0).unwrap(),
+                NaiveTime::from_hms_opt(from.0, from.1, 0).unwrap(),
+                NaiveTime::from_hms_opt(to.0, to.1, 0).unwrap(),
                 1),
             property
-        });
+        }
+    }
+
+    fn reservation() -> ResSumWithItems {
+        let mut reservation = ResSumWithItems::default();
+        reservation.summary.date = NaiveDate::from_ymd_opt(2030, 3, 5).unwrap();
+        reservation.reservations.push(item("Court 1", (8, 0), (9, 30)));
 
         reservation
     }
@@ -304,6 +304,32 @@ mod tests {
         assert_eq!(mail.text, "Date: 05. 03. 2030, items: Court 1: 08:00 - 09:30.");
     }
 
+    #[test]
+    fn mail_message_summary_has_one_item_per_line() {
+        let mut reservation = reservation();
+        reservation.reservations.push(item("Court 2", (10, 0), (11, 0)));
+        reservation.reservations.push(item("Sauna", (18, 0), (20, 0)));
+
+        let mail = MailMessage::new(
+            "admin@example.com".to_string(),
+            "customer@example.com".to_string(),
+            message("Booking", "Items:\n#summary#\nBye"),
+            &reservation);
+
+        assert_eq!(mail.text, "Items:\nCourt 1: 08:00 - 09:30\nCourt 2: 10:00 - 11:00\nSauna: 18:00 - 20:00\nBye");
+    }
+
+    #[test]
+    fn mail_message_summary_is_empty_without_items() {
+        let mail = MailMessage::new(
+            "admin@example.com".to_string(),
+            "customer@example.com".to_string(),
+            message("Booking", "Items: #summary#."),
+            &ResSumWithItems::default());
+
+        assert_eq!(mail.text, "Items: .");
+    }
+
     #[test]
     fn mail_message_without_variables_is_unchanged() {
         let mail = MailMessage::new(