Testing

Tests run the application with coretest, and call the *grpc.Server with grpcservertest.Dial, which serves it on an in memory connection, without listening on a port:

func TestGetUser(t *testing.T) {
  t.Parallel()

  var (
    server *grpc.Server
    spans  *tracetest.InMemoryExporter
    logs   *logtest.InMemoryExporter
  )

  coretest.Start(t, core.New(grpcserver.Module, users.Module), fx.Populate(&server, &spans, &logs))

  client := pb.NewUsersClient(grpcservertest.Dial(t, server))

  user, err := client.GetUser(t.Context(), &pb.GetUserRequest{Id: "42"})
  require.NoError(t, err)
  assert.Equal(t, "42", user.GetId())

  spantest.HasSpan(t, spans,
    spantest.WithName("users.v1.Users/GetUser"),
    spantest.WithAttributeValue(semconv.RPCResponseStatusCode("OK")),
  )
  logtest.HasRecord(t, logs, logtest.WithBody("grpc request"), logtest.WithAttributeValue("method", "GetUser"))
}

The call goes through the whole server: instrumentation, interceptors and service. The connection is closed and the server stopped when the test ends.

Over the network

To test with a real connection, set grpcserver.address to 127.0.0.1:0 and add grpcserver.Serve(): once started, the *grpcserver.Address is the listening address.

var address *grpcserver.Address

coretest.Start(t, app,
  config.AsOptions(config.WithValues(map[string]any{"grpcserver.address": "127.0.0.1:0"})),
  grpcserver.Serve(),
  fx.Populate(&address),
)

conn, err := grpc.NewClient(address.String(), grpc.WithTransportCredentials(insecure.NewCredentials()))