test(backend): expand helper and media coverage

Backend/tests/sfu-noop.test.ts

@@ -0,0 +1,68 @@
+import { describe, expect, test } from 'bun:test';
+
+import { NoopSfuService } from '../media/sfu/noop';
+
+const buildInput = () => ({
+  streamSessionId: 'stream-1',
+  ownerUserId: 'user-1',
+  cameraDeviceId: 'camera-1',
+  requesterDeviceId: 'client-1',
+});
+
+describe('noop SFU service', () => {
+  test('starts a session in starting state', async () => {
+    const service = new NoopSfuService();
+
+    const session = await service.startSession(buildInput());
+
+    expect(session.streamSessionId).toBe('stream-1');
+    expect(session.state).toBe('starting');
+  });
+
+  test('returns the existing session when startSession is called twice', async () => {
+    const service = new NoopSfuService();
+
+    const first = await service.startSession(buildInput());
+    const second = await service.startSession(buildInput());
+
+    expect(second).toEqual(first);
+  });
+
+  test('updates session state through the lifecycle and can read it back', async () => {
+    const service = new NoopSfuService();
+    await service.startSession(buildInput());
+    await service.setSessionState('stream-1', 'live');
+
+    expect(await service.getSession('stream-1')).toEqual({
+      ...buildInput(),
+      state: 'live',
+      createdAt: expect.any(String),
+    });
+  });
+
+  test('marks sessions as ended when endSession is called', async () => {
+    const service = new NoopSfuService();
+    await service.startSession(buildInput());
+    await service.endSession('stream-1');
+
+    expect((await service.getSession('stream-1'))?.state).toBe('ended');
+  });
+
+  test('creates publish and subscribe transports with generated ids', async () => {
+    const service = new NoopSfuService();
+
+    const publish = await service.createPublishTransport({
+      streamSessionId: 'stream-1',
+      cameraDeviceId: 'camera-1',
+    });
+    const subscribe = await service.createSubscribeTransport({
+      streamSessionId: 'stream-1',
+      viewerDeviceId: 'client-1',
+    });
+
+    expect(publish.transportId.startsWith('pub_')).toBe(true);
+    expect(subscribe.transportId.startsWith('sub_')).toBe(true);
+    expect(Array.isArray(publish.iceServers)).toBe(true);
+    expect(Array.isArray(subscribe.iceServers)).toBe(true);
+  });
+});