[Fact] // 1. async Task<IEnumerable<CityListServiceModel>> AllCitiesAsync()
public async void AllCitiesAsync_ShouldReturnModelCollectionOfAllCitiesInDatabase()
{
// Arrange
var country = CountryCreator.Create();
var city = CityCreator.Create(country.Id);
var city2 = CityCreator.Create(country.Id);
var city3 = CityCreator.Create(country.Id);
await this.Context.Countries.AddAsync(country);
await this.Context.Cities.AddRangeAsync(city, city2, city3);
await this.Context.SaveChangesAsync();
var service = new CityService(this.Context);
// Act
var result = await service.AllCitiesAsync();
// Assert
result.Should().AllBeOfType <CityListServiceModel>();
result.Should().HaveCount(3);
}