public void ViewModel_WhenParametersAreCorrect()
{
// Arrange
var flightServiceMock = new Mock <IFlightService>();
var airlineServiceMock = new Mock <IAirlineService>();
var flightController = new FlightController(flightServiceMock.Object, airlineServiceMock.Object);
// Act
var result = flightController.All();
// Assert
Assert.IsInstanceOfType(result, typeof(ViewResult));
}