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ExpectedExceptionAttribute Class

Indicates that an exception is expected during test method execution. This class cannot be inherited.

Inheritance Hierarchy

System.Object
  System.Attribute
    Microsoft.VisualStudio.TestTools.UnitTesting.ExpectedExceptionBaseAttribute
      Microsoft.VisualStudio.TestTools.UnitTesting.ExpectedExceptionAttribute

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

Syntax

'Declaration
<AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple := False, Inherited := True)> _
Public NotInheritable Class ExpectedExceptionAttribute _
    Inherits ExpectedExceptionBaseAttribute
[AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
public sealed class ExpectedExceptionAttribute : ExpectedExceptionBaseAttribute
[AttributeUsageAttribute(AttributeTargets::Method, AllowMultiple = false, Inherited = true)]
public ref class ExpectedExceptionAttribute sealed : public ExpectedExceptionBaseAttribute
[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple = false, Inherited = true)>]
type ExpectedExceptionAttribute =  
    class
        inherit ExpectedExceptionBaseAttribute
    end
public final class ExpectedExceptionAttribute extends ExpectedExceptionBaseAttribute

The ExpectedExceptionAttribute type exposes the following members.

Constructors

  Name Description
Public method ExpectedExceptionAttribute(Type) Initializes a new instance of the ExpectedExceptionAttribute class with an expected exception.
Public method ExpectedExceptionAttribute(Type, String) Initializes a new instance of the ExpectedExceptionAttribute class with and expected exception type and a message that describes the exception.

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Properties

  Name Description
Public property AllowDerivedTypes
Public property ExceptionType Gets the expected exception type.
Protected property NoExceptionMessage Infrastructure. (Inherited from ExpectedExceptionBaseAttribute.)
Protected property TestContext Infrastructure. (Inherited from ExpectedExceptionBaseAttribute.)
Public property TypeId When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)

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Methods

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

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Explicit Interface Implementations

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

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Remarks

This attribute is used to test whether an expected exception is thrown. The test method will pass if the expected exception is thrown. The test will fail if the thrown exception inherits from the expected exception.

If a test has both an ExpectedException attribute and an Assert statement, either one can cause the test to fail. To determine whether the attribute or the statement caused the test to fail, double-click the test result to open the Results Details page for the test. For more information about test results, see Test Results Reported.

This attribute can be specified on a method. There can be only one instance of this attribute on a method.

For more information about how to use attributes, see Extending Metadata Using Attributes.

Examples

The following class contains the method to test:

using System;

namespace MyCSNamespace
{
    public class DivisionClass
    {
        public int Divide(int numerator, int denominator)
        {
            return numerator / denominator;
        }
    }
}
Public Class DivisionClass
   Public Function Divide(ByVal numerator As Integer, ByVal denominator As Integer) As Integer
      Return numerator \ denominator
   End Function
End Class

The following test method tests the Divide method of the DivisionClass object. It tests for the existence of a DivideByZeroException.

using Microsoft.VisualStudio.TestTools.UnitTesting;
using MyCSNamespace;

namespace MyCSTestProject
{
    [TestClass()]
    public class DivisionClassTest
    {
        [TestMethod()]
        [ExpectedException(typeof(System.DivideByZeroException))]
        public void DivideTest()
        {
            DivisionClass target = new DivisionClass();
            int numerator = 4;
            int denominator = 0;
            int actual;
            actual = target.Divide(numerator, denominator);
        }
    }
}
Imports Microsoft.VisualStudio.TestTools.UnitTesting
Imports MyVBProject

<TestClass()> _
Public Class DivisionClassTest
    <TestMethod()> _
    <ExpectedException(GetType(System.DivideByZeroException), "MyMessage")> _
    Public Sub DivideTest()
        Dim target As DivisionClass = New DivisionClass
        Dim numerator As Integer = 4
        Dim denominator As Integer = 0
        Dim actual As Integer
        actual = target.Divide(numerator, denominator)
    End Sub
End Class

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.

See Also

Reference

Microsoft.VisualStudio.TestTools.UnitTesting Namespace