Suppress warnings (googleforgames#16)

* make it testable

* replace deprecated one

* remove some warnings

* make it like Golang style more

* adopt shorter name for some variables

frontend/frontend.go

@@ -50,6 +50,7 @@ func matchmake(ws *websocket.Conn) {
 	stream := protostream.NewProtoStream(ws)
 
 	ctx, cancel := context.WithCancel(ws.Request().Context())
+	defer cancel()
 	assignments := make(chan *pb.Assignment)
 	errs := make(chan error)
 
@@ -79,24 +80,22 @@ func matchmake(ws *websocket.Conn) {
 func streamAssignments(ctx context.Context, assignments chan *pb.Assignment, errs chan error) {
 	conn, err := grpc.Dial("open-match-frontend.open-match.svc.cluster.local:50504", grpc.WithInsecure())
 	if err != nil {
-		errs <- fmt.Errorf("Error dialing open match: %w", err)
+		errs <- fmt.Errorf("error dialing open match: %w", err)
 	}
 	defer conn.Close()
 	fe := pb.NewFrontendServiceClient(conn)
 
 	var ticketId string
-	{
-		req := &pb.CreateTicketRequest{
-			Ticket: &pb.Ticket{},
-		}
+	crReq := &pb.CreateTicketRequest{
+		Ticket: &pb.Ticket{},
+	}
 
-		resp, err := fe.CreateTicket(ctx, req)
-		if err != nil {
-			errs <- fmt.Errorf("Error creating open match ticket: %w", err)
-			return
-		}
-		ticketId = resp.Id
+	resp, err := fe.CreateTicket(ctx, crReq)
+	if err != nil {
+		errs <- fmt.Errorf("error creating open match ticket: %w", err)
+		return
 	}
+	ticketId = resp.Id
 
 	defer func() {
 		_, err := fe.DeleteTicket(context.Background(), &pb.DeleteTicketRequest{TicketId: ticketId})
@@ -105,23 +104,21 @@ func streamAssignments(ctx context.Context, assignments chan *pb.Assignment, err
 		}
 	}()
 
-	{
-		req := &pb.WatchAssignmentsRequest{
-			TicketId: ticketId,
-		}
+	waReq := &pb.WatchAssignmentsRequest{
+		TicketId: ticketId,
+	}
 
-		stream, err := fe.WatchAssignments(ctx, req)
+	stream, err := fe.WatchAssignments(ctx, waReq)
+	if err != nil {
+		errs <- fmt.Errorf("error getting assignment stream: %w", err)
+		return
+	}
+	for {
+		resp, err := stream.Recv()
 		if err != nil {
-			errs <- fmt.Errorf("Error getting assignment stream: %w", err)
+			errs <- fmt.Errorf("error streaming assignment: %w", err)
 			return
 		}
-		for {
-			resp, err := stream.Recv()
-			if err != nil {
-				errs <- fmt.Errorf("Error streaming assignment: %w", err)
-				return
-			}
-			assignments <- resp.Assignment
-		}
+		assignments <- resp.Assignment
 	}
 }