我试图发现如何将async和await关键字应用于我的xUnit测试 . 我使用的是xUnit 1.9和Async CTP 1.3 . 这是我的测试用例
我有一个接口,它指定一个异步方法调用
public interface IDoStuffAsync
{
Task AnAsyncMethod(string value);
}
我有一个使用接口并调用异步方法的类
public class UseAnAsyncThing
{
private readonly IDoStuffAsync _doStuffAsync;
public UseAnAsyncThing(IDoStuffAsync doStuffAsync)
{
_doStuffAsync = doStuffAsync;
}
public async Task DoThatAsyncOperation(string theValue)
{
await _doStuffAsync.AnAsyncMethod(theValue);
}
}
在我的测试中,我希望检查方法 DoThatAsyncOperation
是否正在使用正确的值调用方法,因此我模拟了接口并使用Moq来验证调用
[Fact]
public async void The_test_will_pass_even_though_it_should_fail()
{
var mock = new Mock<IDoStuffAsync>();
var sut = new UseAnAsyncThing(mock.Object);
mock.Setup(x => x.AnAsyncMethod(It.IsAny<string>()));
await sut.DoThatAsyncOperation("test");
// This won't throw a Moq.MockExcpetion so the test appears to pass
// However it does not run
mock.Verify(x => x.AnAsyncMethod("fail"));
}
此测试使用 async
和 await
关键字 . 当它运行时,它错误地通过,因为Moq应断言验证失败 . 调用 sut.DoThatAsyncOperation("test");
后的任何代码都不会运行
[Fact]
public void This_will_work_and_assert_the_reslt()
{
var mock = new Mock<IDoStuffAsync>();
var sut = new UseAnAsyncThing(mock.Object);
mock.Setup(x => x.AnAsyncMethod(It.IsAny<string>()));
sut.DoThatAsyncOperation("test").ContinueWith(y => { });
// This won't throw a Moq.MockExcpetion so the test appears to pass
// However it does not run
mock.Verify(x => x.AnAsyncMethod("fail"));
}
此测试是在没有await和async关键字的情况下设置的,并且传递正常 .
这是xUnit和Moq的预期行为吗?
Update
感谢Stephen的评论,我设法通过进行两次更改来修复第一个测试 . 测试现在返回Task而不是void,Mock也返回一个Task .
[Fact]
public async Task The_test_will_pass_even_though_it_should_fail()
{
var mock = new Mock<IDoStuffAsync>();
var sut = new UseAnAsyncThing(mock.Object);
mock.Setup(x => x.AnAsyncMethod(It.IsAny<string>())).ReturnAsync(true);
await sut.DoThatAsyncOperation("test");
// This now fails as it should
mock.Verify(x => x.AnAsyncMethod("fail"));
}
2 回答
更改单元测试方法以返回
Task
而不是void
,它应该可以工作 . 支持async void
单元测试is being considered for a future release .我在博客上详细描述了why async unit tests don't work by default . (我的博客示例使用MSTest,但每个其他测试运行器都存在相同的问题,包括xUnit pre-1.9) .
我尝试使用“更新”中的代码,但它停止在我正在嘲笑的异步方法中 .
所以要解决这个问题,我必须改变'Return'方法: