TestInitializeAttribute Class

Article
03/28/2012

Identifies the method to run before the test to allocate and configure resources needed by all tests in the test class. This class cannot be inherited.

Inheritance Hierarchy

System.Object
System.Attribute
Microsoft.VisualStudio.TestTools.UnitTesting.TestInitializeAttribute

Namespace: Microsoft.VisualStudio.TestTools.UnitTesting
Assembly: Microsoft.VisualStudio.QualityTools.UnitTestFramework (in Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll)

Syntax

'Declaration
<AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple := False)> _
Public NotInheritable Class TestInitializeAttribute _
    Inherits Attribute

[AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple = false)]
public sealed class TestInitializeAttribute : Attribute

[AttributeUsageAttribute(AttributeTargets::Method, AllowMultiple = false)]
public ref class TestInitializeAttribute sealed : public Attribute

[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple = false)>]
type TestInitializeAttribute =  
    class
        inherit Attribute
    end

public final class TestInitializeAttribute extends Attribute

The TestInitializeAttribute type exposes the following members.

Constructors

	Name	Description
	TestInitializeAttribute	Initializes a new instance of the TestInitializeAttribute class.

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Properties

	Name	Description
	TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)

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Methods

	Name	Description
	Equals	Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)
	Finalize	Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
	GetHashCode	Returns the hash code for this instance. (Inherited from Attribute.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	IsDefaultAttribute	When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)
	Match	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	ToString	Returns a string that represents the current object. (Inherited from Object.)

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Explicit Interface Implementations

	Name	Description
	_Attribute.GetIDsOfNames	Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
	_Attribute.GetTypeInfo	Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
	_Attribute.GetTypeInfoCount	Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
	_Attribute.Invoke	Provides access to properties and methods exposed by an object. (Inherited from Attribute.)

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Remarks

When run in a load test, the method marked with this attribute will run once for every virtual user iteration in the test. If you need to do initialization operations once, that apply to the entire test, use the ClassInitializeAttribute.

The order that methods will be run is:

Methods marked with the AssemblyInitializeAttribute.
Methods marked with the ClassInitializeAttribute.
Methods marked with the TestInitializeAttribute.
Methods marked with the TestMethodAttribute.

This attribute can be specified on a method. Only one instance of this attribute may be applied to a method.

This attribute is used by default in generated code.

For more information about using attributes, see Extending Metadata Using Attributes.

Examples

The SampleClassLib namespace contains the DivideClass class, which in turn contains the method we want to test. This method is called DivideMethod().

using System;
using System.Collections.Generic;
using System.Text;

namespace SampleClassLib
{
   public class DivideClass
   {
      public int DivideMethod(int a)
      {
         return 2 / a;
      }
   }
}

Imports System
Imports System.Collections.Generic
Imports System.Text

Namespace SampleClassLib
    Public Class DivideClass
        Public Function DivideMethod(ByVal a As Integer) As Integer
            Return 2 \ a
        End Function
    End Class
End Namespace

In the following code, the DivideClassTest test class contains a test method called DivideMethodTest. This code also contains attributes that control the initialization and clean-up execution order for the method, class, and assembly.

In particular, note the TestInitialize attribute on the Initialize() method.

using Microsoft.VisualStudio.TestTools.UnitTesting;
using SampleClassLib;
using System;
using System.IO;
using System.Windows.Forms;

namespace TestNamespace
{
   [TestClass()]
   public class DivideClassTest
   {
      [AssemblyInitialize()]
      public static void AssemblyInit(TestContext context)
      {
         MessageBox.Show("Assembly Init");
         }

      [ClassInitialize()]
      public static void ClassInit(TestContext context)
      {
         MessageBox.Show("ClassInit");
      }

      [TestInitialize()]
      public void Initialize()
      {
         MessageBox.Show("TestMethodInit");
      }

      [TestCleanup()]
      public void Cleanup()
      {
         MessageBox.Show("TestMethodCleanup");
      }

      [ClassCleanup()]
      public static void ClassCleanup()
      {
         MessageBox.Show("ClassCleanup");
      }

      [AssemblyCleanup()]
      public static void AssemblyCleanup()
      {
         MessageBox.Show("AssemblyCleanup");
      }

      [TestMethod()]
      [ExpectedException(typeof(System.DivideByZeroException))]
      public void DivideMethodTest()
      {
         DivideClass target = new DivideClass();
         int a = 0; 
         int actual;
         actual = target.DivideMethod(a);
      }
   }
}

Imports Microsoft.VisualStudio.TestTools.UnitTesting
Imports System.Windows.Forms
Imports SCL2 = SampleClassLib2.SampleClassLib
Imports System
Imports System.IO

Namespace TestNamespace

   <TestClass()> _
   Public Class DivideClassTest

      <AssemblyInitialize()> _
      Public Shared Sub AssemblyInit(ByVal context As TestContext)
         MessageBox.Show("Assembly Init")
      End Sub

      <ClassInitialize()> _
      Public Shared Sub ClassInit(ByVal context As TestContext)
         MessageBox.Show("Test Class Init")
      End Sub

      <TestInitialize()> _
      Public Sub Initialize()
         MessageBox.Show("Test Initialize")
      End Sub

      <TestCleanup()> _
      Public Sub Cleanup()
         MessageBox.Show("Test Cleanup")
      End Sub

      <ClassCleanup()> _
      Public Shared Sub ClassCleanup()
         MessageBox.Show("Test Class Cleanup")
      End Sub

      <AssemblyCleanup()> _
      Public Shared Sub AssemblyCleanup()
         MessageBox.Show("Test Assembly Cleanup")
      End Sub

      <TestMethod()> _
      <ExpectedException(GetType(System.DivideByZeroException))> _
      Public Sub DivideMethodTest()
         Dim target As SCL.DivideClass = New SCL.DivideClass
         Dim a As Integer = 0
         Dim actual As Integer
         actual = target.DivideMethod(a)
      End Sub

   End Class
End Namespace

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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