NUnit预期异常 [英] NUnit expected exceptions

问题描述

我有一组测试用例，其中一些预期会抛出异常。因此，我已经设置这些测试的属性来预期如下所示的异常：

  [ExpectedException（System.NullReferenceException ）] 
  

当我在本地运行测试时，但是，当我将测试移动到运行TeamCity的CI服务器时，所有我预期的异常的测试都会失败。这是一个已知的错误。

我知道还有 Assert.Throws<> code> Assert.Throws NUnit提供的方法。

我的问题是如何使用这些而不是我目前使用的属性？

我已经看过了StackOverflow，并尝试了几件事情，没有一个似乎对我有用。

有一个简单的1行解决方案来使用这个方法吗？

解决方案

我不知道你试过的是给你麻烦，但你可以简单地传递一个lambda作为Assert.Throws的第一个参数。这是我的一个测试通过的一个：

  Assert.Throws< ArgumentException>（（）=> pointStore.Store new [] {firstPoint}））; 
  

---

好的，这个例子可能有点冗长。假设我有一个测试

  [Test] 
 [ExpectedException（System.NullReferenceException）] 
 public void TestFoo（）
 {
 MyObject o = null; 
 o.Foo（）; $  o.Foo（）
 
 
 
 
 
 
 
 
 
 
 
 
 $ b $  c> 
 
 
 
然后你会删除 ExpectedException 将您的调用包含在 Assert.Throws 中的 o.Foo（）。
  [测试] 
 public void TestFoo（）
 {
 MyObject o = null; 
 Assert.Throws< NullReferenceException>（（）=> o.Foo（））; 
} 
  
   Assert.Throws  尝试调用代码片段，以便验证它抛出特定的异常。 （）=> DoSomething（）语法表示一个 lambda ，本质上是一个匿名方法。所以在这种情况下，我们告诉 Assert.Throws 来执行代码片段 o.Foo（）。
 
 
 
所以不，你不只是添加一行像你做一个属性;您需要在调用 Assert.Throws 中显式包装测试的将抛出异常的部分。您不必必须使用lambda，但这通常是最方便的。
 
I've got a set of test cases, some of which are expected to throw exceptions. Because of this, I have have set the attributes for these tests to expect exceptions like so:
[ExpectedException("System.NullReferenceException")]
When I run my tests locally all is good. However when I move my tests over to the CI server running TeamCity, all my tests that have expected exceptions fail. This is a known bug.

I am aware that there is also the Assert.Throws<> and Assert.Throws methods that NUnit offers. 

My question is how can I make use of these instead of the attribute I'm currently using?

I've had a look around StackOverflow and tried a few things none of which seem to work for me. 

Is there a simple 1 line solution to using this?
解决方案
I'm not sure what you've tried that is giving you trouble, but you can simply pass in a lambda as the first argument to Assert.Throws.  Here's one from one of my tests that passes:
Assert.Throws<ArgumentException>(() => pointStore.Store(new[] { firstPoint }));




Okay, that example may have been a little verbose.  Suppose I had a test
[Test]
[ExpectedException("System.NullReferenceException")]
public void TestFoo()
{
    MyObject o = null;
    o.Foo();
}
which would pass normally because o.Foo() would raise a null reference exception.

You then would drop the ExpectedException attribute and wrap your call to o.Foo() in an Assert.Throws.
[Test]
public void TestFoo()
{
    MyObject o = null;
    Assert.Throws<NullReferenceException>(() => o.Foo());
}
Assert.Throws "attempts to invoke a code snippet, represented as a delegate, in order to verify that it throws a particular exception."  The () => DoSomething() syntax represents a lambda, essentially an anonymous method.  So in this case, we are telling Assert.Throws to execute the snippet o.Foo().

So no, you don't just add a single line like you do an attribute; you need to explicitly wrap the section of your test that will throw the exception, in a call to Assert.Throws.  You don't necessarily have to use a lambda, but that's often the most convenient.

                        
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