Fix lint errors

proxy/server/target.go

@@ -198,13 +198,14 @@ func (s *TargetStream) Run(nonce uint32, replyChan chan *pb.ProxyReply) {
 		}
 		var err error
 		defer cancel()
-		s.grpcConn, err = s.dialer.DialContext(dialCtx, s.target, opts...)
+		grpcConn, err := s.dialer.DialContext(dialCtx, s.target, opts...)
 		if err != nil {
 			// We cannot create a new stream to the target. So we need to cancel this stream.
 			s.logger.Info("unable to create stream", "status", err)
 			s.cancelFunc()
 			return err
 		}
+		s.grpcConn = grpcConn
 		grpcStream, err := s.grpcConn.NewStream(s.ctx, s.serviceMethod.StreamDesc(), s.serviceMethod.FullName())
 		if err != nil {
 			// We cannot create a new stream to the target. So we need to cancel this stream.
@@ -325,8 +326,10 @@ func (s *TargetStream) Run(nonce uint32, replyChan chan *pb.ProxyReply) {
 
 	// Once all calls are complete, we need to close our network connection
 	// to the server.
-	if closeErr := s.grpcConn.Close(); err == nil && closeErr != nil {
-		err = closeErr
+	if s.grpcConn != nil {
+		if closeErr := s.grpcConn.Close(); err == nil && closeErr != nil {
+			err = closeErr
+		}
 	}
 
 	// The error status may by set/overidden if CloseWith was used to

proxy/server/target_test.go

@@ -35,7 +35,7 @@ import (
 // A TargetDialer than returns an error for all Dials
 type dialErrTargetDialer codes.Code
 
-func (e dialErrTargetDialer) DialContext(ctx context.Context, target string, dialOpts ...grpc.DialOption) (grpc.ClientConnInterface, error) {
+func (e dialErrTargetDialer) DialContext(ctx context.Context, target string, dialOpts ...grpc.DialOption) (ClientConnCloser, error) {
 	return nil, status.Error(codes.Code(e), "")
 }
 
@@ -150,10 +150,14 @@ func (b blockingClientConn) NewStream(ctx context.Context, desc *grpc.StreamDesc
 	return nil, ctx.Err()
 }
 
+func (b blockingClientConn) Close() error {
+	return nil
+}
+
 // a context dialer that returns blockingClientConn
 type blockingClientDialer struct{}
 
-func (b blockingClientDialer) DialContext(ctx context.Context, target string, dialOpts ...grpc.DialOption) (grpc.ClientConnInterface, error) {
+func (b blockingClientDialer) DialContext(ctx context.Context, target string, dialOpts ...grpc.DialOption) (ClientConnCloser, error) {
 	return blockingClientConn{}, nil
 }