GroboContainer.NUnitExtensions

NUnit extensions simplifying DI-container management in tests.

Release Notes

See CHANGELOG.

How to Use

First define GroboContainer configuration for your test suite:

public static class GroboTestMachineryContainerConfigurator
{
    public static ContainerConfiguration GetContainerConfiguration(string testSuiteName)
    {
        return new ContainerConfiguration(new[] { Assembly.LoadFrom("A.dll"), Assembly.LoadFrom("B.dll") });
    }
}

By convention this must be done in a static method GetContainerConfiguration in a class named exactly GroboTestMachineryContainerConfigurator which is placed in the same assembly as your tests.

Then define several helper attributes which will hold logic for different aspects of test environment configuration:

public class WithX : GroboTestSuiteWrapperAttribute
{
    public override void SetUp(string suiteName, Assembly testAssembly, IEditableGroboTestContext suiteContext)
    {
        suiteContext.Container.Configurator.ForAbstraction<IX>().UseType<X>();
    }
}

[WithX]
public class WithY : GroboTestSuiteWrapperAttribute
{
    public override void SetUp(string suiteName, Assembly testAssembly, IEditableGroboTestContext suiteContext)
    {
        suiteContext.Container.Configurator.ForAbstraction<Y>().UseInstances(new Y("qwerty"));
    }
}

public class WithFixedSeedRandom : GroboTestSuiteWrapperAttribute
{
    public override void SetUp(string suiteName, Assembly testAssembly, IEditableGroboTestContext suiteContext)
    {
        suiteContext.Container.Configurator.ForAbstraction<Random>().UseInstances(new Random(42));
    }
}

public class AndLogTestName : GroboTestMethodWrapperAttribute
{
    public override void SetUp(string testName, IEditableGroboTestContext suiteContext, IEditableGroboTestContext methodContext)
    {
        Console.Out.WriteLine($"Start running test: {testName}");
    }

    public override void TearDown(string testName, IEditableGroboTestContext suiteContext, IEditableGroboTestContext methodContext)
    {
        Console.Out.WriteLine($"Finished running test: {testName}");
    }
}

And now you can write your test cases with minimum container configuration boilerplate:

[GroboTestSuite("SomeTestSuite"), WithY, WithFixedSeedRandom, AndLogTestName]
public interface ISomeTestSuite { }

public class Part01 : ISomeTestSuite
{
    [Test]
    public void TestCase01()
    {
        x.Foo();
        y.Bar(rng.Next());
    }

    [Injected]
    private readonly IX x;

    [Injected]
    private readonly Y y;

    [Injected]
    private readonly Random rng;
}

public class Part02 : ISomeTestSuite
{
    [Test]
    public void TestCase02()
    {
        x.Foo();
    }

    [Injected]
    private readonly IX x;
}

Note that we don't specify [WithX] on ISomeTestSuite explicitly because WithY attribute is itself marked with [WithX].

You can have as many test suites in a single assembly as you like. And each test suite can have its own environment configuration. In particular each test suite will be served with a separate DI-container instance.

Code defined in each inheritor of GroboTestSuiteWrapperAttribute is executed once per test suite for which it is applied no matter how many test classes constitute it. On the other hand code defined in inheritor of GroboTestMethodWrapperAttribute is executed once per test method.