关于录屏相关的消息格式需要封一层，放在on-message下，利用on-message传递

test/websockethandler.test.ts

@@ -8,6 +8,20 @@ Date.now = jest.fn(() => 1482363367071);
 
 const anyParticipantId = expect.any(String);
 
+function recordingEnvelope(connectionId: string, data: any): any {
+  const innerData = { ...data };
+  delete innerData.type;
+  return {
+    from: connectionId,
+    to: "",
+    type: "on-message",
+    data: JSON.stringify({
+      type: data.type,
+      data: innerData
+    })
+  };
+}
+
 describe('websocket signaling test in public mode', () => {
   let server: WS;
   let client: WebSocket;
@@ -212,20 +226,17 @@ describe('websocket signaling test in private mode', () => {
     };
 
     expect(wsHandler.broadcastRecordingStarted(session)).toBe(true);
-    await expect(server).toReceiveMessage(expected);
-    await expect(server).toReceiveMessage(expected);
+    await expect(server).toReceiveMessage(recordingEnvelope(connectionId, expected));
+    await expect(server).toReceiveMessage(recordingEnvelope(connectionId, expected));
 
     expect(wsHandler.broadcastRecordingPeerRequest(session)).toBe(true);
-    await expect(server).toReceiveMessage({
+    const peerRequest = {
       ...expected,
       type: 'recording-peer-request',
       mediaMode: 'webrtc-sendonly'
-    });
-    await expect(server).toReceiveMessage({
-      ...expected,
-      type: 'recording-peer-request',
-      mediaMode: 'webrtc-sendonly'
-    });
+    };
+    await expect(server).toReceiveMessage(recordingEnvelope(connectionId, peerRequest));
+    await expect(server).toReceiveMessage(recordingEnvelope(connectionId, peerRequest));
   });
 
   test('send offer from session1', async () => {