Testing a gRPC service

Question

I\'d like to test a gRPC service written in Go. The example I\'m using is the Hello World server example from the grpc-go repo.

The protobuf definition is as follows

Answer 1

I came up with the following implementation which may not be the best way of doing it. Mainly using the TestMain function to spin up the server using a goroutine like that:

const (
    port = ":50051"
)

func Server() {
    lis, err := net.Listen("tcp", port)
    if err != nil {
        log.Fatalf("failed to listen: %v", err)
    }
    s := grpc.NewServer()
    pb.RegisterGreeterServer(s, &server{})
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }
}
func TestMain(m *testing.M) {
    go Server()
    os.Exit(m.Run())
}

and then implement the client in the rest of the tests:

func TestMessages(t *testing.T) {

    // Set up a connection to the Server.
    const address = "localhost:50051"
    conn, err := grpc.Dial(address, grpc.WithInsecure())
    if err != nil {
        t.Fatalf("did not connect: %v", err)
    }
    defer conn.Close()
    c := pb.NewGreeterClient(conn)

    // Test SayHello
    t.Run("SayHello", func(t *testing.T) {
        name := "world"
        r, err := c.SayHello(context.Background(), &pb.HelloRequest{Name: name})
        if err != nil {
            t.Fatalf("could not greet: %v", err)
        }
        t.Logf("Greeting: %s", r.Message)
        if r.Message != "Hello "+name {
            t.Error("Expected 'Hello world', got ", r.Message)
        }

    })
}