OneTimeSetUp

This attribute is to identify methods that are called once prior to executing any of the tests in a fixture. It may appear on methods of a TestFixture or a SetUpFixture.

OneTimeSetUp methods may be either static or instance methods and you may define more than one of them in a fixture. Normally, multiple OneTimeSetUp methods are only defined at different levels of an inheritance hierarchy, as explained below.

If a OneTimeSetUp method fails or throws an exception, none of the tests in the fixture are executed and a failure or error is reported.

Example

namespace NUnit.Tests
{
  using System;
  using NUnit.Framework;

  [TestFixture]
  public class SuccessTests
  {
    [OneTimeSetUp]
    public void Init()
    { /* ... */ }

    [OneTimeTearDown]
    public void Cleanup()
    { /* ... */ }

    [Test]
    public void Add()
    { /* ... */ }
  }
}

Inheritance

The OneTimeSetUp attribute is inherited from any base class. Therefore, if a base class has defined a OneTimeSetUp method, that method will be called before any methods in the derived class.

You may define a OneTimeSetUp method in the base class and another in the derived class. NUnit will call base class OneTimeSetUp methods before those in the derived classes.

Warning

If a base class OneTimeSetUp method is overridden in the derived class, NUnit will not call the base class OneTimeSetUp method; NUnit does not anticipate usage that includes hiding the base method. Note that you may have a different name for each method; as long as both have the [OneTimeSetUp] attribute present, each will be called in the correct order.

Notes

  • Although it is possible to define multiple OneTimeSetUp methods in the same class, you should rarely do so. Unlike methods defined in separate classes in the inheritance hierarchy, the order in which they are executed is not guaranteed.

  • OneTimeSetUp methods may be async if running under .NET 4.0 or higher.

  • OneTimeSetUp methods run in the context of the TestFixture or SetUpFixture, which is separate from the context of any individual test cases. It's important to keep this in mind when using TestContext methods and properties within the method.

  • When using FixtureLifeCycle with LifeCycle.InstancePerTestCase, the OneTimeSetUp method must be static and is only called once. This is required so that the setup method does not access instance fields or properties that are reset for every test.

  • When set on a base class the method is invoked for each fixture that inherits from this base class and its invoked for the base class too if its not abstract. Use SetUpFixture if this only needs to be run once or put the code in a static constructor.

See Also