fix: multiple bug fixes

isolated users, db backup, weird disconnect issues for long voice sessions,

toju-app/src/app/store/rooms/rooms-helpers-snapshot.spec.ts

@@ -0,0 +1,45 @@
+import {
+  reconcileRoomSnapshotChannels,
+  sanitizeRoomSnapshot
+} from './rooms.helpers';
+
+describe('room snapshot helpers', () => {
+  it('drops empty channel arrays from outgoing snapshots', () => {
+    expect(sanitizeRoomSnapshot({ channels: [] }).channels).toBeUndefined();
+  });
+
+  it('keeps cached channels when incoming snapshot has none', () => {
+    const cachedChannels = [
+      { id: 'general', name: 'general', type: 'text', position: 0 },
+      { id: 'updates', name: 'updates', type: 'text', position: 1 }
+    ] as const;
+
+    expect(reconcileRoomSnapshotChannels(cachedChannels as never, undefined)).toEqual(cachedChannels);
+    expect(reconcileRoomSnapshotChannels(cachedChannels as never, [] as never)).toEqual(cachedChannels);
+  });
+
+  it('keeps richer cached channels when incoming snapshot is smaller', () => {
+    const cachedChannels = [
+      { id: 'general', name: 'general', type: 'text', position: 0 },
+      { id: 'updates', name: 'updates', type: 'text', position: 1 },
+      { id: 'voice', name: 'General', type: 'voice', position: 0 }
+    ] as const;
+    const incomingChannels = [
+      { id: 'general', name: 'general', type: 'text', position: 0 }
+    ] as const;
+
+    expect(reconcileRoomSnapshotChannels(cachedChannels as never, incomingChannels as never)).toEqual(cachedChannels);
+  });
+
+  it('accepts incoming channels when snapshot is at least as complete', () => {
+    const cachedChannels = [
+      { id: 'general', name: 'general', type: 'text', position: 0 }
+    ] as const;
+    const incomingChannels = [
+      { id: 'general', name: 'general', type: 'text', position: 0 },
+      { id: 'updates', name: 'updates', type: 'text', position: 1 }
+    ] as const;
+
+    expect(reconcileRoomSnapshotChannels(cachedChannels as never, incomingChannels as never)).toEqual(incomingChannels);
+  });
+});