Is it pointless to implement IDisposable in unit tests? - unit-testing

I have the following unit tests for an extension method. Both tests share same object instantiation (IBinanceClient), so I did it in the constructor. It implements IDisposable, because IBinanceClient does too. The question is: is implementing IDisposable in unit tests really useful/a good practice?
I'm open-minded for any recommendations about the rest of the code as well, even tho it's not a lot.
using Binance.Net;
using Binance.Net.Interfaces;
using Binance.Net.Objects;
using XBot.Models.Strategies.Whore;
using CryptoExchange.Net.Authentication;
using System;
using Xunit;
namespace XBot.Tests
{
public class NoobStrategyExtensionsTests : IDisposable
{
private readonly IBinanceClient _client;
public NoobStrategyExtensionsTests()
{
_client = new BinanceClient(new BinanceClientOptions()
{
ApiCredentials = new ApiCredentials("-", "-"),
AutoTimestamp = true,
AutoTimestampRecalculationInterval = TimeSpan.FromMinutes(30)
});
}
[Fact]
public void CheckAndFillBNB_OneBNB_ReturnsTrue()
{
// Arrange
// Act
bool actual = _client.CheckAndFillBNB(1, true);
// Assert
Assert.True(actual);
}
[Theory]
[InlineData(3, false)]
[InlineData(1, true)]
[InlineData(2, false)]
[InlineData(1.99, true)]
public void CheckAndFillBNB_MultipleBNBQuantities_ReturnsTrue(decimal input, bool expected)
{
// Arrange
// Act
bool actual = _client.CheckAndFillBNB(input, true);
// Assert
Assert.Equal(expected, actual);
}
public void Dispose()
{
if (_client != null)
_client.Dispose();
}
}
}

Related

How to use Microsoft.Extensions.Configuration.IConiguration in my XUnit unit testing

In my Asp.net Core 2.0 application, I am trying to unit test my data service layer (.Net Standard Class Library) that uses the Microsoft.Extensions.Configuration.IConfiguration dependency injection.
I am using XUnit and don't know how to pass IConfiguration from my unit test class. I tried the following implementation and getting the error
Message: The following constructor parameters did not have matching fixture data: IConfiguration configuration.
I am really new to the testing frameworks and don't even know if dependency injection can be used as I am trying to do in my code snippet.
My Unit test class is as follow
public class SqlRestaurantDataCLUnitTest
{
private readonly IConfiguration configuration;
public SqlRestaurantDataCLUnitTest(IConfiguration configuration)
{
this.configuration = configuration;
}
[Fact]
public void AddTest()
{
var restaurantDataCL = new SqlRestaurantDataCL(configuration);
var restaurant = new Restaurant
{
Name = "TestName",
Cuisine = CuisineType.None
};
var result = restaurantDataCL.Add(restaurant);
Assert.IsNotType(null, result.Id);
}
}
My data service layer is as follow
public class SqlRestaurantDataCL : IRestaurantDataCL
{
private readonly IConfiguration configuration;
public SqlRestaurantDataCL(IConfiguration configuration)
{
this.configuration = configuration;
}
public Restaurant Add(Restaurant restaurant)
{
using (var db = GetConnection())
{
string insertSql = #"INSERT INTO [dbo].[RESTAURANTS]([Cuisine], [Name])
OUTPUT INSERTED.*
VALUES (#Cuisine, #Name)";
restaurant = db.QuerySingle<Restaurant>(insertSql, new
{
Cuisine = restaurant.Cuisine,
Name = restaurant.Name
});
return restaurant;
}
}
private IDbConnection GetConnection()
{
return new SqlConnection(configuration.GetSection(Connection.Name).Value.ToString());
}
}
public class Connection
{
public static string Name
{
get { return "ConnectionStrings: OdeToFood"; }
}
}
Unit tests have a very useful habit of exposing design issues. In this case you have made some design choices that prove difficult to test because of tight coupling to framework concerns as well as static concerns.
First, it looks like SqlRestaurantDataCL actually depends on a connection factory
public interface IDbConnectionFactory {
IDbConnection GetConnection();
}
Which would refactor the data implementation as advised to depend on that abstraction.
public class SqlRestaurantDataCL : IRestaurantDataCL {
private readonly IDbConnectionFactory factory;
public SqlRestaurantDataCL(IDbConnectionFactory factory) {
this.factory = factory;
}
public Restaurant Add(Restaurant restaurant) {
using (var connection = factory.GetConnection()) {
string insertSql = #"INSERT INTO [dbo].[RESTAURANTS]([Cuisine], [Name])
OUTPUT INSERTED.*
VALUES (#Cuisine, #Name)";
restaurant = connection.QuerySingle<Restaurant>(insertSql, new {
Cuisine = restaurant.Cuisine,
Name = restaurant.Name
});
return restaurant;
}
}
//...
}
The assumption is that Dapper is being used to make the query above.
With the introduction of the abstracted dependencies, they can be mocked as needed when testing in isolation.
public class SqlRestaurantDataCLUnitTest {
[Fact]
public void AddTest() {
//Arrange
var connection = new Mock<IDbConnection>();
var factory = new Mock<IDbConnectionFactory>();
factory.Setup(_ => _.GetConnection()).Returns(connection.Object);
//...setup the connection to behave as expected
var restaurantDataCL = new SqlRestaurantDataCL(factory.Object);
var restaurant = new Restaurant {
Name = "TestName",
Cuisine = CuisineType.None
};
//Act
var result = restaurantDataCL.Add(restaurant);
//Assert
Assert.IsNotType(null, result.Id);
}
}
Now if you meant to actually touch the real database then this is not an isolation unit test but instead an integration test, that will have a different approach.
In production code, the factory can be implemented
public class SqlDbConnectionFactory : IDbConnectionFactory {
private readonly ConnectionSetings connectionSettings;
SqlDbConnectionFactory(ConnectionSetings connectionSettings) {
this.connectionSettings = connectionSettings;
}
public IDbConnection GetConnection() {
return new SqlConnection(connectionSettings.Name));
}
}
Where ConnectionSetings is defined as a simple POCO to store the connection string
public class ConnectionSetings {
public string Name { get; set; }
}
In the composition root the settings can be extracted from configurations
IConfiguration Configuration; //this would have been set previously
public void ConfigureServices(IServiceCollection services) {
//...
var settings = Configuration
.GetSection("ConnectionStrings:OdeToFood")
.Get<ConnectionSetings>();
//...verify settings (if needed)
services.AddSingleton(settings);
services.AddSingleton<IDbConnectionFactory,SqlDbConnectionFactory>();
services.AddSingleton<IRestaurantDataCL,SqlRestaurantDataCL>();
//Note: while singleton was used above, You can decide to use another scope
// if so desired.
}
There was really no need to be passing IConfiguration around as it is more of a framework concern that is really only relevant at start up.

How to mock event in HttpModule

I have a simple Http module:
public class CustomLoggingModule : IHttpModule
{
public void Init(HttpApplication context)
{
context.BeginRequest += BeginRequest;
context.EndRequest += EndRequest;
}
public void BeginRequest(object sender, EventArgs eventArgs)
{
//some code
}
public void EndRequest(object sender, EventArgs eventArgs)
{
//some
}
public void Dispose()
{
}
}
How can I unit test this? Especially how is it possible to mock events? Can anyone give some simple example?
Not sure why you have decided to hardwire the dependencies as new LogService() and new HttpContextWrapper(HttpContext.Current) within the CustomLoggingModule. If want to test whether LogInfo() method is called or not, it becomes lot easier if you can externalize these dependencies so you can inject stubbed/mocked version etc.
Also your question does not state that you are using an IOC container. You can register the HttpModule with the container and provide external dependencies at runtime. Your question also does not state that using an isoloation/mock object framework.
Therefore I will provide you with a solution that you can verify whether LogInfo method is called, using hand written stubs and mocks.
To achieve this, we need to refactor CustomLoggingModule a bit, so it becomes more testable.
System Under Test (SUT)
public class CustomLoggingModule : IHttpModule
{
public ILogService LogService { get; set; }
public Func<ILoggingHttpContextWrapper> LogginHttpContextWrapperDelegate { get; set; }
public void Init(HttpApplication context) {
context.BeginRequest += BeginRequest;
context.EndRequest += EndRequest;
}
public CustomLoggingModule() {
LogginHttpContextWrapperDelegate = () => new LoggingHttpContextWrapper();
}
public void BeginRequest(object sender, EventArgs eventArgs) {
LogService.LogInfo(LogginHttpContextWrapperDelegate().HttpContextWrapper);
}
public void EndRequest(object sender, EventArgs eventArgs) {
//some
}
public void Dispose(){ }
}
As you see above, I have introduced 2 additional properties - ILogService so I can provide a Mocked verion and a delegate Func which allows me to stub the
new HttpContextWrapper(HttpContext.Current);
public interface ILoggingHttpContextWrapper {
HttpContextWrapper HttpContextWrapper { get; }
}
public class LoggingHttpContextWrapper : ILoggingHttpContextWrapper
{
public LoggingHttpContextWrapper() {
HttpContextWrapper = new HttpContextWrapper(HttpContext.Current);
}
public HttpContextWrapper HttpContextWrapper { get; private set; }
}
And then your real ILogService
public interface ILogService {
void LogInfo(HttpContextWrapper httpContextWrapper);
}
public class LogService : ILogService {
public void LogInfo(HttpContextWrapper httpContextWrapper)
{
//real logger implementation
}
}
Unit Test :
You would create a MockLoggerService, so you can verify the interaction i,e whether the LogInfo() method was called, etc. You also need a stubbed LoggingHttpContextWrapper to provide the fake HttpContextWrapper to the SUT (System Under Test)/ CustomLoggingModule.
public class StubLoggingHttpContextWrapper : ILoggingHttpContextWrapper
{
public StubLoggingHttpContextWrapper(){}
public HttpContextWrapper HttpContextWrapper { get; private set; }
}
public class MockLoggerService : ILogService
{
public bool LogInfoMethodIsCalled = false;
public void LogInfo(HttpContextWrapper httpContextWrapper) {
LogInfoMethodIsCalled = true;
}
}
MockLoggerService is very important. It is not the real logger service, but it is the mocked version. When we do public class MockLoggerService : ILogService this means that we are providing another layer of indirection to the logger service so we can verify the interaction of the behaviour.
You also notice that I have provided a boolean variable to verify whether the LogInfo method is called or not. This allows me to call this method from the SUT, and verify whether the method being called or not.
Now Your Unit Test can be implemented as below.
[TestMethod]
public void CustomLoggingModule_BeginRequest_VerifyLogInfoMethodIsCalled()
{
var sut = new CustomLoggingModule();
var loggerServiceMock = new MockLoggerService();
var loggingHttpContextWrapperStub = new StubLoggingHttpContextWrapper();
sut.LogService = loggerServiceMock;
sut.LogginHttpContextWrapperDelegate = () => loggingHttpContextWrapperStub;
sut.BeginRequest(new object(), new EventArgs());
Assert.IsTrue(loggerServiceMock.LogInfoMethodIsCalled);
}
I had the same issue with my custom http module and decided I won't give up that easily and will do all I can to trigger the BeginRequest event in unit test. I had to actually read through the source code of HttpApplication class and use reflection to invoke the method.
[TestMethod]
public void EventTriggered_DoesNotError()
{
using (var application = new HttpApplication())
{
var module = new CustomLoggingModule();
module.Init(application);
FireHttpApplicationEvent(application, "EventBeginRequest", this, EventArgs.Empty);
}
}
private static void FireHttpApplicationEvent(object onMe, string invokeMe, params object[] args)
{
var objectType = onMe.GetType();
object eventIndex = (object)objectType.GetField(invokeMe, System.Reflection.BindingFlags.Static | System.Reflection.BindingFlags.NonPublic).GetValue(onMe);
EventHandlerList events = (EventHandlerList)objectType.GetField("_events", System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.NonPublic).GetValue(onMe);
EventHandler handler = (EventHandler)events[eventIndex];
Delegate[] delegates = handler.GetInvocationList();
foreach (Delegate dlg in delegates)
{
dlg.Method.Invoke(dlg.Target, args);
}
}

Can a particular constructor argument of an injected SUT using Autodata xUnit Theories?

Consider the following test,
[Theory, MyConventions]
public void GetClientExtensionReturnsCorrectValue(BuilderStrategy sut)
{
var expected = ""; // <--??? the value injected into BuilderStrategy
var actual = sut.GetClientExtension();
Assert.Equal(expected, actual);
}
and the custom attribute I'm using:
public class MyConventionsAttribute : AutoDataAttribute {
public MyConventionsAttribute()
: base(new Fixture().Customize(new AutoMoqCustomization())) {}
}
and the SUT:
class BuilderStrategy {
private readonly string _clientID;
private readonly IDependency _dependency;
public void BuilderStrategy(string clientID, IDependency dependency) {
_clientID = clientID;
_dependency = dependency;
}
public string GetClientExtension() {
return _clientID.Substring(_clientID.LastIndexOf("-") + 1);
}
}
I need to know what value was injected into the constructor parameter clientID so that I can use it to compare with the output of GetClientExtension. Is it possible to do this while still writing this style of test where the SUT is injected into the test method?
If you expose the injected clientID (and dependency as well) as read-only properties, you can always query their values:
public class BuilderStrategy {
private readonly string _clientID;
private readonly IDependency _dependency;
public void BuilderStrategy(string clientID, IDependency dependency) {
_clientID = clientID;
_dependency = dependency;
}
public string GetClientExtension() {
return _clientID.Substring(_clientID.LastIndexOf("-") + 1);
}
public string ClientID
{
get { return _clientID; }
}
public IDependency Dependency
{
get { return _dependency; }
}
}
This doesn't break encapsulation, but is rather known as Structural Inspection.
With this change, you could now rewrite the test like this:
[Theory, MyConventions]
public void GetClientExtensionReturnsCorrectValue(BuilderStrategy sut)
{
var expected = sut.ClientID.Substring(sut.ClientID.LastIndexOf("-") + 1);
var actual = sut.GetClientExtension();
Assert.Equal(expected, actual);
}
Some people don't like duplicating production code in the unit test, but I would rather argue that if you follow Test-Driven Development, it's the production code that duplicates the test code.
In any case, this is a technique known as Derived Value. In my opinion, as long as it retains a cyclomatic complexity of 1, we can still trust the test. Additionally, as long as the duplicated code only appears in two places, the rule of three suggests that we should keep it like that.

Cannot seem to moq EF CodeFirst 4.1.Help anyone?

I have been given the task to evaluate codeFirst and possible to use for all our future projects.
The evaluation is based on using codeFirst with an existing database.
Wondering if it's possible to mock the repository using codeFirst 4.1.(no fakes)
The idea is to inject a repository into a service and moq the repository.
I have been looking on the net but I have only found an example using fakes.I dont want to use fakes I want to use moq.
I think my problem is in the architecture of the DAL.(I would like to use unitOfWork etc.. by I need to show a working moq example)
Below is my attempt(Failed miserably) due to lack of knowledge on Code first 4.1.
I have also uploaded a solution just in case somebody is in good mood and would like to change it.
http://cid-9db5ae91a2948485.office.live.com/browse.aspx/Public%20Folder?uc=1
I am open to suggestions and total modification to my Dal.Ideally using Unity etc.. but I will worry about later.
Most importantly I need to be able to mock it. Without ability to use MOQ we will bin the project using EF 4.1
Failed attempt
//CodeFirst.Tests Project
[TestClass]
public class StudentTests
{
[TestMethod]
public void Should_be_able_to_verify_that_get_all_has_been_called()
{
//todo redo test once i can make a simple one work
//Arrange
var repository = new Mock<IStudentRepository>();
var expectedStudents = new List<Student>();
repository.Setup(x => x.GetAll()).Returns(expectedStudents);
//act
var studentService = new StudentService(repository.Object);
studentService.GetAll();
//assert
repository.Verify(x => x.GetAll(), Times.AtLeastOnce());
}
}
//CodeFirst.Common Project
public class Student
{
public int StudentId { get; set; }
public string Name { get; set; }
public string Surname { get; set; }
}
public interface IStudentService
{
IEnumerable<Student> GetAll();
}
//CodeFirst.Service Project
public class StudentService:IStudentService
{
private IStudentRepository _studentRepository;
public StudentService()
{
}
public StudentService(IStudentRepository studentRepository)
{
_studentRepository = studentRepository;
}
public IEnumerable<Student> GetAll()
{
//TODO when mocking using moq this will actually call the db as we need a separate class.
using (var ctx = new SchoolContext("SchoolDB"))
{
_studentRepository = new StudentRepository(ctx);
var students = _studentRepository.GetAll().ToList();
return students;
}
}
}
//CodeFirst.Dal Project
public interface IRepository<T> where T : class
{
T GetOne(Expression<Func<T, bool>> predicate);
IEnumerable<T> GetAll();
IEnumerable<T> Find(Expression<Func<T, bool>> predicate);
void Add(T entity);
void Delete(T entity);
T Single(Func<T, bool> predicate);
T First(Func<T, bool> predicate);
}
public class RepositoryBase<T> : IRepository<T> where T : class
{
private readonly IDbSet<T> _dbSet;
public RepositoryBase(DbContext dbContext)
{
_dbSet = dbContext.Set<T>();
if (_dbSet == null) throw new InvalidOperationException("Cannot create dbSet ");
}
protected virtual IDbSet<T> Query
{
get { return _dbSet; }
}
public T GetOne(Expression<Func<T, bool>> predicate)
{
return Query.Where(predicate).FirstOrDefault();
}
public IEnumerable<T> GetAll()
{
return Query.ToArray();
}
public IEnumerable<T> Find(Expression<Func<T, bool>> predicate)
{
return Query.Where(predicate).ToArray();
}
public void Add(T entity)
{
_dbSet.Add(entity);
}
public void Delete(T entity)
{
_dbSet.Remove(entity);
}
public T Single(Func<T, bool> predicate)
{
return Query.Where(predicate).SingleOrDefault();
}
public T First(Func<T, bool> predicate)
{
return Query.Where(predicate).FirstOrDefault();
}
}
public class SchoolContext:DbContext
{
public SchoolContext(string connectionString):base(connectionString)
{
Database.SetInitializer<SchoolContext>(null);
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
//Not sure why I have to do this.Without this when using integration testing
//as opposed to UnitTests it does not work.
modelBuilder.Entity<Student>().ToTable("Student"); }
public DbSet<Student> Students { get; set; }
}
public interface IStudentRepository:IRepository<Student>
{
}
public class StudentRepository : RepositoryBase<Student>, IStudentRepository
{
public StudentRepository(DbContext dbContext)
: base(dbContext)
{
}
public IEnumerable<Student> GetStudents()
{
return GetAll();
}
}
Again feel free to modify or whatever is needed to help me to get something together.
Thanks a lot for your help
When I started with repository and unit of work patterns I used the implementation similar to this (it is for ObjectContext API but converting it to DbContext API is simple). We used that implementation with MOQ and Unity without any problems. By the time implementations of repository and unit of work have evolve as well as the approach of injecting. Later on we found that whole this approach has serious pitfalls but that was alredy discussed in other questions I referenced here (I highly recommend you to go through these links).
It is very surprising that you are evaluating the EFv4.1 with high emphasis on mocking and unit testing and in the same time you defined service method which is not unit-testable (with mocking) at all. The main problem of you service method is that you are not passing repository/context as dependency and because of that you can't mock it. The only way to test your service and don't use the real repository is using some very advanced approach = replacing mocking and MOQ with detouring (for example Moles framework).
First what you must do is replacing your service code with:
public class StudentService : IStudentService
{
private readonly IStudentRepository _studentRepository;
public StudentService(IStudentRepository studentRepository)
{
_studentRepository = studentRepository;
}
public IEnumerable<Student> GetAll()
{
return _studentRepository.GetAll().ToList();
}
}
Btw. this is absolutely useless code and example of silly layering which doesn't offer any useful functionality. Just wrapping the call to repository only shows that service is not needed at all as well as unit testing this method is not needed. The main point here is integration test for GetAll method.
Anyway if you want to unit thest such method with MOQ you will do:
[TestClass]
public class StudentsServiveTest
{
private Mock<IRespository<Student>> _repo;
[TestInitialize]
public void Init()
{
_repo = new Mock<IRepository<Student>>();
_repo.Setup(r => r.GetAll()).Returns(() => new Student[]
{
new Student { StudentId = 1, Name = "A", Surname = "B" },
new Student { StudentId = 2, Name = "B", Surname = "C" }
});
}
[TestMethod]
public void ShouldReturnAllStudents()
{
var service = new StudentsService(_repo.Object);
var data = service.GetAll();
_repo.Verify(r => r.GetAll(), Times.Once());
Assert.IsNotNull(data);
Assert.AreEqual(2, data.Count);
}
}
The issue from what I can see is that you are throwing away the mock object and newing up a new instance
_studentRepository = new StudentRepository(ctx);
Perhaps add a method on the interface to add the context object and reuse the same instance that was injected in the constructor.
using (var ctx = new SchoolContext("SchoolDB"))
{
_studentRepository.Context = ctx;
var students = _studentRepository.GetAll().ToList();
return students;
}
}

Using RhinoMocks, how can I assert that one of several methods was called?

Consider the following service interfaces:
public interface IServiceA
{
void DoSomething(string s);
void DoSomething(string s, bool b);
}
public interface IServiceB
{
void DoSomething();
}
The implementation of IServiceB depends on IServiceA like this:
public class ServiceB : IServiceB
{
private IServiceA _serviceA;
public ServiceB(IServiceA serviceA)
{
_serviceA = serviceA;
}
public void DoSomething()
{
_serviceA.DoSomething("Hello", true);
}
}
Ie. the dependency is injected in the constructor.
Now consider a unit test for the DoSomething() method. I wish to assert that one of the overloaded DoSomething-methods in IServiceA is called, but following a general principle that unit tests shouldn't know too much about the internal workings of the method being tested, I wish to be agnostic about which of the two overloads is called. Consider the following unit test:
[TestFixture]
public class ServiceBTests
{
[Test]
public void DoSomething_CallsServiceA()
{
var serviceAMock = MockRepository.GenerateMock<IServiceA>();
var service = new ServiceB(serviceAMock);
service.DoSomething();
// Problem: How to check if EITHER:
serviceAMock.AssertWasCalled(s => s.DoSomething(Arg<String>.Is.NotNull, Arg<bool>.Is.Anything));
// OR:
serviceAMock.AssertWasCalled(s => s.DoSomething(Arg<String>.Is.NotNull));
}
}
How can I assert that either one or the other of the two methods was called?
You could manually set a boolean flag like so:
[TestFixture]
public class ServiceBTests
{
[Test]
public void DoSomething_CallsServiceA()
{
var serviceAMock = MockRepository.GenerateMock<IServiceA>();
bool called = false;
serviceAMock.Stub(
x => x.DoSomething(Arg<String>.Is.NotNull, Arg<bool>.Is.Anything))
.WhenCalled(delegate { called = true; });
serviceAMock.Stub(x => x.DoSomething(Arg<String>.Is.NotNull))
.WhenCalled(delegate { called = true; });
var service = new ServiceB(serviceAMock);
service.DoSomething();
Assert.IsTrue(called);
}
}
I don't think this very useful though. Unit tests are concerned with anything that is observable from outside of the component boundaries. Method calls to mocks are part of that. In other words, it is OK if you test for a specific overload being called. After all, there must be a reason why you use that overload and not the other one.
If you really want the unit test to remain ignorant of the implementation, you wouldn't be allowed to assert method calls on mocks at all. That would be a severe restriction on your ability to write tests.