refactor(imap): move fetch_metadata() to Session

src/imap.rs

@@ -1415,15 +1415,16 @@ impl Imap {
 
         Ok((last_uid, received_msgs))
     }
+}
 
+impl Session {
     /// Retrieves server metadata if it is supported.
     ///
     /// We get [`/shared/comment`](https://www.rfc-editor.org/rfc/rfc5464#section-6.2.1)
     /// and [`/shared/admin`](https://www.rfc-editor.org/rfc/rfc5464#section-6.2.2)
     /// metadata.
     pub(crate) async fn fetch_metadata(&mut self, context: &Context) -> Result<()> {
-        let session = self.session.as_mut().context("no session")?;
+        if !self.can_metadata() {
-        if !session.can_metadata() {
             return Ok(());
         }
 
@@ -1442,7 +1443,7 @@ impl Imap {
 
         let mailbox = "";
         let options = "";
-        let metadata = session
+        let metadata = self
             .get_metadata(mailbox, options, "(/shared/comment /shared/admin)")
             .await?;
         for m in metadata {

src/scheduler.rs

@@ -473,9 +473,11 @@ async fn inbox_loop(
                 warn!(ctx, "Failed to download messages: {:#}", err);
             }
 
-            if let Err(err) = connection.fetch_metadata(&ctx).await {
+            if let Some(session) = connection.session.as_mut() {
+                if let Err(err) = session.fetch_metadata(&ctx).await {
                     warn!(ctx, "Failed to fetch metadata: {err:#}.");
                 }
+            }
 
             fetch_idle(&ctx, &mut connection, FolderMeaning::Inbox).await;
         }