diff --git a/packages/mixer-connection/src/lib/state/mixer-store.spec.ts b/packages/mixer-connection/src/lib/state/mixer-store.spec.ts
new file mode 100644
index 0000000..a8fbd84
--- /dev/null
+++ b/packages/mixer-connection/src/lib/state/mixer-store.spec.ts
@@ -0,0 +1,68 @@
+import { firstValueFrom, Subject } from 'rxjs';
+import { MixerConnection } from '../mixer-connection';
+import { MixerStore } from './mixer-store';
+
+describe('Mixer Store', () => {
+  let conn: { allMessages$: Subject<string> };
+  let mixerStore: MixerStore;
+
+  function sendMessage(message: string): void {
+    conn.allMessages$.next(message);
+  }
+
+  beforeEach(() => {
+    conn = {
+      allMessages$: new Subject<string>(),
+    };
+
+    mixerStore = new MixerStore(conn as unknown as MixerConnection);
+  });
+
+  it('should reduce channel sync state', async () => {
+    sendMessage('BMSG^SYNC^mySyncId^5');
+    sendMessage('BMSG^SYNC^mySyncId^6');
+    sendMessage('BMSG^SYNC^mySyncId^10');
+    expect(await firstValueFrom(mixerStore.syncState$)).toEqual({ mySyncId: 10 });
+
+    sendMessage('BMSG^SYNC^SYNC_ID^8');
+    sendMessage('BMSG^SYNC^SYNC_ID^20');
+    expect(await firstValueFrom(mixerStore.syncState$)).toEqual({ mySyncId: 10, SYNC_ID: 20 });
+
+    sendMessage('BMSG^SYNC^mySyncId^44');
+    sendMessage('BMSG^SYNC^anotherSyncId^11');
+    expect(await firstValueFrom(mixerStore.syncState$)).toEqual({
+      mySyncId: 44,
+      SYNC_ID: 20,
+      anotherSyncId: 11,
+    });
+  });
+
+  describe('state$', () => {
+    it('should reduce SETD/SETS messages to state', async () => {
+      sendMessage('SETD^i.3.mute^0');
+      sendMessage('SETD^i.4.mute^1');
+      sendMessage('SETS^i.10.name^channelname');
+      expect(await firstValueFrom(mixerStore.state$)).toEqual({
+        'i.3.mute': 0,
+        'i.4.mute': 1,
+        'i.10.name': 'channelname',
+      });
+
+      sendMessage('SETS^i.10.name^anothername');
+      sendMessage('SETD^i.3.mute^1');
+      expect(await firstValueFrom(mixerStore.state$)).toEqual({
+        'i.3.mute': 1,
+        'i.4.mute': 1,
+        'i.10.name': 'anothername',
+      });
+    });
+
+    it('should ignore messages other than SETD or SETS', async () => {
+      sendMessage('SETD^abc^def');
+
+      sendMessage('FOO^bar^baz');
+      sendMessage('XYZ^xyz^xyz');
+      expect(await firstValueFrom(mixerStore.state$)).toEqual({ abc: 'def' });
+    });
+  });
+});