1 files changed, 16 insertions, 14 deletions
diff --git a/app/imap.js b/app/imap.js
index f2e8cc2..181d9cf 100644
--- a/app/imap.js
+++ b/app/imap.js
@@ -20,6 +20,16 @@ async function connect (options) {
   return client;
 }
 
+ImapFlow.prototype.fetchArray = async function (range, query, options = {}) {
+  const msgsGenerator = await this.fetch(range, query, options);
+  const msgs = [];
+  for await (const msg of msgsGenerator) {
+    msgs.push(msg);
+  }
+
+  return msgs;
+};
+
 async function listTreeFrom (event, options) {
   const client = await connect(options);
 
@@ -47,26 +57,18 @@ async function migrate (event, { from, to }) {
     const fromMailbox = await fromClient.getMailboxLock(fromFolder.path);
     const toMailbox = await toClient.getMailboxLock(fromFolder.path);
     try {
-      const toMsgsGenerator = await toClient.fetch('1:*', { flags: true, envelope: true, source: true });
-      const toMsgs = [];
-      for await (const toMsg of toMsgsGenerator) {
-        toMsgs.push(toMsg);
-      }
-      const fromMsgsGenerator = await fromClient.fetch('1:*', { flags: true, envelope: true, source: true });
+      const toMsgs = await toClient.fetchArray('1:*', { flags: true, envelope: true, source: true });
+      const fromMsgs = await fromClient.fetchArray('1:*', { flags: true, envelope: true, source: true });
 
-      for await (const fromMsg of fromMsgsGenerator) {
-        if (toMsgs.some((toMsg) => Buffer.compare(toMsg.source, fromMsg.source) === 0)) {
-          continue;
-        }
+      const msgs = fromMsgs.filter((fromMsg) => !toMsgs.some((toMsg) => Buffer.compare(toMsg.source, fromMsg.source) === 0));
 
-        await toClient.append(fromFolder.path, fromMsg.source, Array.from(fromMsg.flags), fromMsg.envelope.date);
+      await toClient.noop();
+      for (const msg of msgs) {
+        toClient.append(fromFolder.path, msg.source, Array.from(msg.flags), msg.envelope.date);
       }
     } finally {
       fromMailbox.release();
       toMailbox.release();
     }
   }
-
-  await fromClient.logout();
-  await toClient.logout();
 }