How to unit test ServiceStack? - sql

Question

I love SS but I'm scratching my head trying to unit test my business layer. I'm new to unit testing andmocking and been reading up on NSubstitute as this looks like a fun mocking layer.
I have my file structure roughly like this:
MainAppHostProject*
|
-AppStart
-AppHost <-- standard apphost
DtoProject*
|
-HelloWorldDto <-- simple POCO to
ServiceLayerProject*
|
-HelloWorldService <-- service interface that merely passes/sends Dtos to/from business layer
BusinessLayerProject*
|
-HelloWorldManager <-- logic to construct response and this class extends 'Service' (letting me access Db, session, etc)...sidenote: maybe i shouldve called this a HelloWorldRepository?
-CustomAuthProvider
-CustomUserSession
DaoProject*
|
-HelloWorldDao <-- POCO of table structure
The Apphost points to the HelloWorldService assembly and registers the SQL Server database as standard.
Everything actually works great and I have been able to build up the logic in a cleaner way. Unfortunately I wish to embark on unit testing BUT I dont know how to decouple the database.
I tried to register a fake in memory database but then I think there's incompatibility issues with how I've used code to get identities etc in SQL Server vs SQLite ways.
// container.Register<IDbConnectionFactory>(c => new OrmLiteConnectionFactory(":memory:", false, SqliteOrmLiteDialectProvider.Instance));
// container.Register<IDbConnectionFactory>(c => new OrmLiteConnectionFactory(":memory:", false, SqlServerDialect.Provider));
I just want to decouple and unit test. Any ideas please?
***UPDATE
public class UnitTest1
{
private Container container;
[TestMethod]
public void TestMethod1()
{
container = new Container();
// container.Register<IDbConnectionFactory>(new OrmLiteConnectionFactory(":memory:", false, SqliteDialect.Provider));
// sqlite didnt work so attempting with a real DB for now
var connectionString = #"Data Source=.\SQLEXPRESS;Initial Catalog=XXX;Integrated Security=True";
container.Register<IDbConnectionFactory>(c => new OrmLiteConnectionFactory(connectionString, SqlServerDialect.Provider));
// dependencies are injecting ok
container.RegisterAutoWiredAs<FeedbackRepo, IFeedbackRepo>();
// service is autowiring --> leading to good injections
container.RegisterAutoWired<FeedbackService>();
var service = container.Resolve<FeedbackService>();
service.SetResolver(new BasicResolver(container));
// unit test is working well
var request = new DTO.FeedbackDto { Message = "test" };
bool result = service.Post(request);
}
}
At the moment trying to get 'Db' to stop being null in my derived Service classes.

Answer 1

If you want to unit test a ServiceStack Service in isolation there are a couple of different approaches you can take. The base Service class itself is just a simple C# class which lets you define and inject dependencies manually or by using the built-in IOC container.
We'll illustrate both approaches using this simple unit test example that tests this simple Service:
DTOs
public class FindRockstars
{
public int? Aged { get; set; }
public bool? Alive { get; set; }
}
public class GetStatus
{
public string LastName { get; set; }
}
public class RockstarStatus
{
public int Age { get; set; }
public bool Alive { get; set; }
}
public class Rockstar
{
public int Id { get; set; }
public string FirstName { get; set; }
public string LastName { get; set; }
public int? Age { get; set; }
}
Implementation
public class SimpleService : Service
{
public IRockstarRepository RockstarRepository { get; set; }
public List<Rockstar> Get(FindRockstars request)
{
return request.Aged.HasValue
? Db.Select<Rockstar>(q => q.Age == request.Aged.Value)
: Db.Select<Rockstar>();
}
public RockstarStatus Get(GetStatus request)
{
var rockstar = RockstarRepository.GetByLastName(request.LastName);
if (rockstar == null)
throw HttpError.NotFound("'{0}' is not a Rockstar".Fmt(request.LastName));
var status = new RockstarStatus
{
Alive = RockstarRepository.IsAlive(request.LastName)
}.PopulateWith(rockstar); //Populates with matching fields
return status;
}
}
This Service provides 2 operations, FindRockstars which makes db queries directly in the service class itself, and GetStatus which uses a repository instead for all its Data access.
Using an in-memory database
If you're accessing Db from directly within your service implementation you're going to want to make use of a real DB given the ADO.NET IDbConnection requires a lot of effort to mock. You can do this in the same way you would register your dependencies in ServiceStack itself, by using the built-in IOC. For a unit test we can do this without an AppHost by just use a new Container in your TestFixtureSetup, e.g:
Test Setup
private ServiceStackHost appHost;
[TestFixtureSetUp]
public void TestFixtureSetUp()
{
appHost = new BasicAppHost().Init();
var container = appHost.Container;
container.Register<IDbConnectionFactory>(
new OrmLiteConnectionFactory(":memory:", SqliteDialect.Provider));
container.RegisterAutoWiredAs<RockstarRepository, IRockstarRepository>();
container.RegisterAutoWired<SimpleService>();
using (var db = container.Resolve<IDbConnectionFactory>().Open())
{
db.DropAndCreateTable<Rockstar>();
db.InsertAll(SeedData);
}
}
[TestFixtureTearDown]
public void TestFixtureTearDown()
{
appHost.Dispose();
}
With everything setup we can now test the service just like a normal C# class in isolation independently of ServiceStack itself:
[Test]
public void Using_in_memory_database()
{
//Resolve the autowired service from IOC and set Resolver for the base class
var service = appHost.Container.Resolve<SimpleService>();
var rockstars = service.Get(new FindRockstars { Aged = 27 });
rockstars.PrintDump(); //Print a dump of the results to Console
Assert.That(rockstars.Count, Is.EqualTo(SeedData.Count(x => x.Age == 27)));
var status = service.Get(new GetStatus { LastName = "Vedder" });
Assert.That(status.Age, Is.EqualTo(48));
Assert.That(status.Alive, Is.True);
status = service.Get(new GetStatus { LastName = "Hendrix" });
Assert.That(status.Age, Is.EqualTo(27));
Assert.That(status.Alive, Is.False);
Assert.Throws<HttpError>(() =>
service.Get(new GetStatus { LastName = "Unknown" }));
}
Manually injecting dependencies
If you prefer your unit tests not to use an in-memory database, you can instead choose to mock your dependencies. In this example we'll use a stand-alone Mock, but you can reduce boilerplate by using mocking library like Moq instead.
public class RockstarRepositoryMock : IRockstarRepository
{
public Rockstar GetByLastName(string lastName)
{
return lastName == "Vedder"
? new Rockstar(6, "Eddie", "Vedder", 48)
: null;
}
public bool IsAlive(string lastName)
{
return lastName == "Grohl" || lastName == "Vedder";
}
}
[Test]
public void Using_manual_dependency_injection()
{
var service = new SimpleService
{
RockstarRepository = new RockstarRepositoryMock()
};
var status = service.Get(new GetStatus { LastName = "Vedder" });
Assert.That(status.Age, Is.EqualTo(48));
Assert.That(status.Alive, Is.True);
Assert.Throws<HttpError>(() =>
service.Get(new GetStatus { LastName = "Hendrix" }));
}
This example doesn't need a container as we're injecting all the dependencies manually. I've also added this example to the Testing wiki docs.