mstest实现类似单元测试nunit中assert.throws功能

我们做单元测试NUnit中,有一个断言Assert.Throws很好用,但当我们使用MsTest时你需要这样写:

[TestMethod]
[ExpectedException(typeof(ArgumentNullException))]
public void WriteToTextFile()
{
PDFUtility.WriteToTextFile("D:\\ACA.pdf", null);
}

现在让我们来扩展一下也实现类似成功能,增加一个类,代码如下:

/// <summary>
/// Useful assertions for actions that are expected to throw an exception.
/// </summary>
public static class ExceptionAssert
{
/// <summary>
/// Executes an exception, expecting an exception to be thrown.
/// Like Assert.Throws in NUnit.
/// </summary>
/// <param name="action">The action to execute</param>
/// <returns>The exception thrown by the action</returns>
public static Exception Throws(Action action)
{
return Throws(action, null);
}/// <summary>
/// Executes an exception, expecting an exception to be thrown.
/// Like Assert.Throws in NUnit.
/// </summary>
/// <param name="action">The action to execute</param>
/// <param name="message">The error message if the expected exception is not thrown</param>
/// <returns>The exception thrown by the action</returns>
public static Exception Throws(Action action, string message)
{
try
{
action();
}
catch (Exception ex)
{
// The action method has thrown the expected exception.
// Return the exception, in case the unit test wants to perform further assertions on it.
return ex;
}// If we end up here, the expected exception was not thrown. Fail!
throw new AssertFailedException(message ?? "Expected exception was not thrown.");
}/// <summary>
/// Executes an exception, expecting an exception of a specific type to be thrown.
/// Like Assert.Throws in NUnit.
/// </summary>
/// <param name="action">The action to execute</param>
/// <returns>The exception thrown by the action</returns>
public static T Throws<T>(Action action) where T : Exception
{
return Throws<T>(action, null);
}/// <summary>
/// Executes an exception, expecting an exception of a specific type to be thrown.
/// Like Assert.Throws in NUnit.
/// </summary>
/// <param name="action">The action to execute</param>
/// <param name="message">The error message if the expected exception is not thrown</param>
/// <returns>The exception thrown by the action</returns>
public static T Throws<T>(Action action, string message) where T : Exception
{
try
{
action();
}
catch (Exception ex)
{
T actual = ex as T;
if (actual == null)
{
throw new AssertFailedException(message ?? String.Format("Expected exception of type {0} not thrown. Actual exception type was {1}.", typeof(T), ex.GetType()));
}// The action method has thrown the expected exception of type 'T'.
// Return the exception, in case the unit test wants to perform further assertions on it.
return actual;
}// If we end up here, the expected exception of type 'T' was not thrown. Fail!
throw new AssertFailedException(message ?? String.Format("Expected exception of type {0} not thrown.", typeof(T)));
}
}

[TestMethod]
public void WriteToTextFile2()
{
//Implement Assert.Throws in MSTest
ExceptionAssert.Throws<ArgumentNullException>(()=> PDFUtility.WriteToTextFile("D:\\ACA.pdf", null)
,"Output file path should not be null");
}

到此这篇关于mstest实现类似单元测试nunit中assert.throws功能就介绍到这了。记住该记住的，忘记该忘记的。改变能改变的，接受不能改变的。更多相关mstest实现类似单元测试nunit中assert.throws功能内容请查看相关栏目，小编编辑不易，再次感谢大家的支持！