ExpectedExceptionAttribute Class
Indicates that an exception is expected during test method execution. This class cannot be inherited.
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 ExpectedExceptionAttribute _
Inherits Attribute
'Usage
Dim instance As ExpectedExceptionAttribute
[AttributeUsageAttribute(AttributeTargets.Method, AllowMultiple = false)]
public sealed class ExpectedExceptionAttribute : Attribute
[AttributeUsageAttribute(AttributeTargets::Method, AllowMultiple = false)]
public ref class ExpectedExceptionAttribute sealed : public Attribute
public final class ExpectedExceptionAttribute extends Attribute
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
Inheritance Hierarchy
System.Object
System.Attribute
Microsoft.VisualStudio.TestTools.UnitTesting.ExpectedExceptionAttribute
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.