fix: resume background delivery after purge (#425)

frontend/background-issue-sync.js

@@ -205,6 +205,7 @@ function createBackgroundIssueSync({
   batch = work => work(), requestTimeoutMs = 15000,
 }) {
   let purgeRequested = false;
+  let activePurge = null;
   let activeFlush = null;
   const activeRequests = new Set();
   const timeoutMs = Math.max(1, Number(requestTimeoutMs) || 15000);
@@ -422,15 +423,26 @@ function createBackgroundIssueSync({
     return activeFlush;
   }
 
-  async function purge() {
+  function purge() {
+    if (activePurge) return activePurge;
     purgeRequested = true;
     activeRequests.forEach(controller => controller.abort());
-    if (activeFlush) await activeFlush.catch(() => {});
-    await store.close?.();
+    activePurge = (async () => {
+      if (activeFlush) await activeFlush.catch(() => {});
+      await store.close?.();
+    })();
+    return activePurge;
+  }
+
+  async function resume() {
+    const pendingPurge = activePurge;
+    if (pendingPurge) await pendingPurge;
+    if (activePurge === pendingPurge) activePurge = null;
+    purgeRequested = false;
   }
 
   return {
-    flush, send, purge,
+    flush, send, purge, resume,
     reconcile: (items, outboxLane) => store.reconcile(items, outboxLane),
     snapshot: () => store.snapshot(),
     setReceiptPreference: (ownerLogin, enabled) => store.setReceiptPreference(ownerLogin, enabled),

frontend/service-worker.js

@@ -1,6 +1,6 @@
 const BASE = new URL('./', self.location.href).pathname;
 importScripts(BASE + 'static/background-issue-sync.js');
-const CACHE = 'stackchain-dashboard-shell-v69';
+const CACHE = 'stackchain-dashboard-shell-v70';
 const OFFLINE_LEASE_URL = new URL(BASE + '__offline-session-lease', self.location.origin).href;
 const OUTAGE_STATUSES = new Set([500, 502, 503, 504]);
 const NAVIGATION_TIMEOUT_MS = self.__STACKCHAIN_NAVIGATION_TIMEOUT_MS || 4000;
@@ -217,7 +217,10 @@ self.addEventListener('sync', event => {
 });
 
 self.addEventListener('message', event => {
-  if (event.data?.type === 'stackchain-resume-outbox') event.waitUntil(flushAndNotify());
+  if (event.data?.type === 'stackchain-resume-outbox') event.waitUntil((async () => {
+    await issueSync.resume();
+    await flushAndNotify();
+  })());
   if (event.data?.type === 'stackchain-session-lease') {
     event.waitUntil(storeOfflineLease(event.data.expiresAt));
   }