fix: prevent offline queue replay data loss

tests/offline-mutation-queue.test.mjs

@@ -43,3 +43,49 @@ test('replay removes acknowledged rows and retains the first failed row', async
   clearOfflineMutations('replay@example.test');
 });
 
+test('concurrent reconnect signals send each queued mutation once', async () => {
+  clearOfflineMutations('concurrent@example.test');
+  enqueueTenderMutation('concurrent@example.test', { key: 'a', patch: { takipte: true }, snapshot: {}, version: 0 });
+  let sends = 0;
+  let release;
+  const gate = new Promise(resolve => { release = resolve; });
+  const send = async () => { sends += 1; await gate; return { version: 1 }; };
+  const first = replayOfflineMutations('concurrent@example.test', send);
+  const second = replayOfflineMutations('concurrent@example.test', send);
+  release();
+  const [a, b] = await Promise.all([first, second]);
+  assert.equal(sends, 1);
+  assert.deepEqual(a, b);
+  assert.equal(offlineMutationCount('concurrent@example.test'), 0);
+});
+
+test('a mutation added during replay is retained with the acknowledged server version', async () => {
+  clearOfflineMutations('during-replay@example.test');
+  enqueueTenderMutation('during-replay@example.test', { key: 'a', patch: { takipte: true }, snapshot: {}, version: 3 });
+  const first = await replayOfflineMutations('during-replay@example.test', async item => {
+    enqueueTenderMutation('during-replay@example.test', { key: 'a', patch: { kanbanStatus: 'teklif_hazirlaniyor' }, snapshot: {}, version: item.version });
+    return { version: 4 };
+  });
+  assert.equal(first.pending, 1);
+  const retained = listOfflineMutations('during-replay@example.test')[0];
+  assert.equal(retained.version, 4);
+  assert.deepEqual(retained.patch, { takipte: true, kanbanStatus: 'teklif_hazirlaniyor' });
+  const versions = [];
+  await replayOfflineMutations('during-replay@example.test', async item => { versions.push(item.version); return { version: 5 }; });
+  assert.deepEqual(versions, [4]);
+  assert.equal(offlineMutationCount('during-replay@example.test'), 0);
+});
+
+test('a full queue rejects a new tender instead of silently discarding an older change', () => {
+  clearOfflineMutations('full@example.test');
+  for (let index = 0; index < 100; index += 1) {
+    enqueueTenderMutation('full@example.test', { key: String(index), patch: { takipte: true }, snapshot: {}, version: 0 });
+  }
+  assert.throws(
+    () => enqueueTenderMutation('full@example.test', { key: 'overflow', patch: { takipte: true }, snapshot: {}, version: 0 }),
+    /kuyruğu dolu/,
+  );
+  assert.equal(offlineMutationCount('full@example.test'), 100);
+  assert.equal(listOfflineMutations('full@example.test')[0].key, '0');
+  clearOfflineMutations('full@example.test');
+});