add Pong message handling and corresponding unit test in SocketIO

Author: doghappy

src/SocketIOClient/V2/SocketIO.cs

@@ -138,6 +138,9 @@ public async Task OnNextAsync(IMessage message)
             case MessageType.Ping:
                 OnPing?.Invoke(this, EventArgs.Empty);
                 break;
+            case MessageType.Pong:
+                HandlePongMessage(message);
+                break;
             case MessageType.Connected:
                 await HandleConnectedMessage(message);
                 break;
@@ -167,4 +170,10 @@ private Task HandleConnectedMessage(IMessage message)
         Connected = true;
         return Task.CompletedTask;
     }
+
+    private void HandlePongMessage(IMessage message)
+    {
+        var pong = (PongMessage)message;
+        OnPong?.Invoke(this, pong.Duration);
+    }
 }

tests/SocketIOClient.UnitTests/V2/SocketIOTests.cs

@@ -231,15 +231,18 @@ public async Task OnPing_PingMessageWasReceived_EventHandlerIsCalled()
         called.Should().BeTrue();
     }
 
-    // [Fact]
-    // public async Task OnPong_PongMessageWasReceived_EventHandlerIsCalled()
-    // {
-    //     TimeSpan? ts = null;
-    //     _io.OnPong+= (_, e) => ts=e;
-    //     await ConnectAsync();
-    //
-    //     await _io.OnNextAsync(new PongMessage());
-    //
-    //     called.Should().BeTrue();
-    // }
+    [Fact]
+    public async Task OnPong_PongMessageWasReceived_EventHandlerIsCalled()
+    {
+        TimeSpan? ts = null;
+        _io.OnPong += (_, e) => ts = e;
+        await ConnectAsync();
+
+        await _io.OnNextAsync(new PongMessage
+        {
+            Duration = TimeSpan.FromSeconds(2),
+        });
+
+        ts.Should().Be(TimeSpan.FromSeconds(2));
+    }
 }