Simplify tests and avoid unnecessary race conditions.

mocks_test.go

@@ -128,21 +128,13 @@ func setupTestConnection(t *testing.T, config *Config) (
 
 	// Wire WriteMessage to push to outgoingData channel
 	mockSocket.WriteMessageFunc = func(msgType int, data []byte) error {
-		mockSocket.mu.Lock()
-		defer mockSocket.mu.Unlock()
-
 		select {
+		case outgoingData <- mockOutgoingData{msgType: msgType, data: data}:
+			return nil
 		case <-mockSocket.closed:
 			return io.EOF
 		default:
-			select {
-			case outgoingData <- mockOutgoingData{msgType: msgType, data: data}:
-				return nil
-			case <-mockSocket.closed:
-				return io.EOF
-			default:
-				return fmt.Errorf("mock outgoing chanel unavailable")
-			}
+			return fmt.Errorf("mock outgoing chanel unavailable")
 		}
 	}