fix: Emit WebxdcInstanceDeleted events when deleting a chat (#6670)

Author: iequidoo

src/chat.rs

@@ -793,6 +793,14 @@ impl ChatId {
         context
             .sql
             .transaction(|transaction| {
+                let mut stmt = transaction.prepare("SELECT id FROM msgs WHERE chat_id=? AND type=?")?;
+                let rows = stmt.query_map((self, Viewtype::Webxdc), |row| row.get(0))?;
+                // Let's emit events optimistically (before the transaction completes) and not
+                // return webxdc `MsgId`s from the transaction because otherwise we need a vector of
+                // indefinite size in memory.
+                for id in rows {
+                    context.emit_event(EventType::WebxdcInstanceDeleted { msg_id: id? });
+                }
                 transaction.execute(
                     "UPDATE imap SET target=? WHERE rfc724_mid IN (SELECT rfc724_mid FROM msgs WHERE chat_id=?)",
                     (delete_msgs_target, self,),

src/webxdc/webxdc_tests.rs

@@ -1789,6 +1789,37 @@ async fn test_webxdc_delete_event() -> Result<()> {
     Ok(())
 }
 
+#[tokio::test(flavor = "multi_thread", worker_threads = 2)]
+async fn test_chat_delete() -> Result<()> {
+    let alice = &TestContext::new_alice().await;
+
+    let chat_id = create_group_chat(alice, ProtectionStatus::Unprotected, "foo").await?;
+    send_webxdc_instance(alice, chat_id).await?;
+
+    let chat_id = create_group_chat(alice, ProtectionStatus::Unprotected, "bar").await?;
+    let instance = send_webxdc_instance(alice, chat_id).await?;
+    alice.send_text(chat_id, "wtf").await;
+
+    chat_id.delete(alice).await?;
+    let EventType::WebxdcInstanceDeleted { msg_id } = alice
+        .evtracker
+        .get_matching(|evt| matches!(evt, EventType::WebxdcInstanceDeleted { .. }))
+        .await
+    else {
+        unreachable!();
+    };
+    assert_eq!(msg_id, instance.id);
+    assert!(alice
+        .evtracker
+        .get_matching_opt(alice, |evt| matches!(
+            evt,
+            EventType::WebxdcInstanceDeleted { .. }
+        ))
+        .await
+        .is_none());
+    Ok(())
+}
+
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
 async fn change_logging_webxdc() -> Result<()> {
     let alice = TestContext::new_alice().await;