fix metaRPCClientFactory id handling (#11116)

* fix metaRPCClientFactory id handling

app/scripts/lib/metaRPCClientFactory.js

@@ -6,6 +6,7 @@ class MetaRPCClient {
   constructor(connectionStream) {
     this.connectionStream = connectionStream;
     this.notificationChannel = new SafeEventEmitter();
+    this.uncaughtErrorChannel = new SafeEventEmitter();
     this.requests = new Map();
     this.connectionStream.on('data', this.handleResponse.bind(this));
     this.connectionStream.on('end', this.close.bind(this));
@@ -17,34 +18,47 @@ class MetaRPCClient {
     });
   }
 
+  onUncaughtError(handler) {
+    this.uncaughtErrorChannel.addListener('error', (error) => {
+      handler(error);
+    });
+  }
+
   close() {
     this.notificationChannel.removeAllListeners();
+    this.uncaughtErrorChannel.removeAllListeners();
   }
 
   handleResponse(data) {
     const { id, result, error, method, params } = data;
+    const isNotification = id === undefined && error === undefined;
     const cb = this.requests.get(id);
 
-    if (method && params && id) {
+    if (method && params && !isNotification) {
       // dont handle server-side to client-side requests
       return;
     }
-    if (method && params && !id) {
+    if (method && params && isNotification) {
       // handle servier-side to client-side notification
       this.notificationChannel.emit('notification', data);
       return;
     }
-    if (!cb) {
-      // not found in request list
-      return;
-    }
 
     if (error) {
       const e = new EthereumRpcError(error.code, error.message, error.data);
       // preserve the stack from serializeError
       e.stack = error.stack;
-      this.requests.delete(id);
-      cb(e);
+      if (cb) {
+        this.requests.delete(id);
+        cb(e);
+        return;
+      }
+      this.uncaughtErrorChannel.emit('error', e);
+      return;
+    }
+
+    if (!cb) {
+      // not found in request list
       return;
     }
 

app/scripts/lib/metaRPCClientFactory.test.js

@@ -85,4 +85,58 @@ describe('metaRPCClientFactory', function () {
       });
     });
   });
+
+  it('should be able to handle notifications', function (done) {
+    const streamTest = createThoughStream();
+    const metaRPCClient = metaRPCClientFactory(streamTest);
+
+    metaRPCClient.onNotification((notification) => {
+      assert(notification.method, 'foobarbaz');
+      done();
+    });
+
+    // send a notification
+    streamTest.write({
+      jsonrpc: '2.0',
+      method: 'foobarbaz',
+      params: ['bar'],
+    });
+  });
+
+  it('should be able to handle errors with no id', function (done) {
+    const streamTest = createThoughStream();
+    const metaRPCClient = metaRPCClientFactory(streamTest);
+
+    metaRPCClient.onUncaughtError((error) => {
+      assert(error.code, 1);
+      done();
+    });
+
+    streamTest.write({
+      jsonrpc: '2.0',
+      error: {
+        code: 1,
+        message: 'error msg',
+      },
+    });
+  });
+
+  it('should be able to handle errors with null id', function (done) {
+    const streamTest = createThoughStream();
+    const metaRPCClient = metaRPCClientFactory(streamTest);
+
+    metaRPCClient.onUncaughtError((error) => {
+      assert(error.code, 1);
+      done();
+    });
+
+    streamTest.write({
+      jsonrpc: '2.0',
+      id: null,
+      error: {
+        code: 1,
+        message: 'error msg',
+      },
+    });
+  });
 });