MbUnit uses custom attributes (as in NUnit) to mark types that contain tests and mark methods as tests.

A type tagged with the TestFixtureAttribute can contain an arbitrary number of test methods. Each method is detected by MbUnit and transformed into a test.

Creating your first test.

using System;
using System.IO;
using MbUnit.Framework;

[TestFixture]
public class MyTestFixture
{
    private TextWriter writer = null;

    [Test]
    public void WriteLine()
    {
        this.writer = new StringWriter();
        this.writer.WriteLine("hello world");
        Console.WriteLine(this.writer.ToString());
    }
}

Negative tests

You can also verify that a method throws an exception using the ExpectedExceptionAttribute attribute as in the example below:

[Test]
[ExpectedException(typeof(FormatException))]
public void WriteLineWithFormatOutOfRange()
{
   this.writer = new StringWriter();
   this.writer.WriteLine("{1}", writer);
}

The ExpectedExceptionAttribute is a TestDecorator. MbUnit provides a long list of such attributes but you can also define your own.

Set up and tear down of each test

Our current test has a lot of duplicated code, specialy initializing the writer field. You can define a setup method (tagged with SetUpAttribute) that will be run before each test. Similarly, a tear down method (tagged with TearDownAttribute) can be defined. The tear down method will be run after each test even if it fails.

[SetUp]
public void SetUp()
{
    this.writer = new StringWriter();
}

[TearDown]
public void CleanUp()
{
    Console.WriteLine("Cleaning up");
}

Set up and tear down of the fixture

At last, one can add a set up and tear down method at the fixture level using the TestFixtureSetUpAttribute and TestFixtureTearDownAttribute.

[TestFixtureSetUp]
public void FixtureSetUp()
{
    ...
}

[TestFixtureTearDown]
public void FixtureTearDown()
{
    ...
}