C# 如何使用Moq为异步函数引发异常

我正在使用xUnit和Moq编写测试用例

我在测试类中使用下面的代码来测试另一个类方法的

catch（）

private readonly  IADLS_Operations _iADLS_Operations;

[Fact]
public void CreateCSVFile_Failure()
{
    var dtData = new DataTable();
    string fileName = "";
   var   mockClient = new Mock<IHttpHandler>();

    this._iADLS_Operations = new ADLS_Operations(mockClient.Object);

    mockClient.Setup(repo => repo.PostAsync(It.IsAny<string>(), It.IsAny<HttpContent>(), It.IsAny<string>()))
        .Returns(() => Task.FromResult(new HttpResponseMessage(HttpStatusCode.BadRequest)));

    mockClient.Setup(repo => repo.SendAsync(It.IsAny<HttpRequestMessage>(), It.IsAny<string>()))
        .Returns(() => Task.FromResult(new HttpResponseMessage(HttpStatusCode.BadRequest)));  // here I want to return Exception instead of BadRequest. How to do that.

    Exception ex = Assert.Throws<Exception>(() => this._iADLS_Operations.CreateCSVFile(dtData, fileName).Result);
    Assert.Contains("Exception occurred while executing method:", ex.Message);
}

---

如何实现这一点。

正如@Johnny在评论中提到的，您可以将代码中的

返回

替换为

抛出

，如：

mockClient.Setup(repo => repo.SendAsync(It.IsAny<HttpRequestMessage>(), It.IsAny<string>())).Throws(new Exception("exception message"));

mockClient.Setup（repo=>repo.SendAsync（It.IsAny（），It.IsAny（））.Throws（新异常（“异常消息”））；

此外，您还可以抛出如下异常：

mockClient.Setup(repo => repo.SendAsync(It.IsAny<HttpRequestMessage>(), It.IsAny<string>())).Throws<InvalidOperationException>();

mockClient.Setup（repo=>repo.sendsync（It.IsAny（），It.IsAny（））.Throws（）；

---

您可以找到有关抛出异常和moq的更多信息。

考虑到被测代码的异步性质，如果测试代码也是异步的，那就更好了。Moq具有异步功能

[Fact]
public async Task CreateCSVFile_Failure() {
    //Arrange
    var dtData = new DataTable();
    string fileName = "";
    var mockClient = new Mock<IHttpHandler>();

    this._iADLS_Operations = new ADLS_Operations(mockClient.Object);

    mockClient
        .Setup(repo => repo.PostAsync(It.IsAny<string>(), It.IsAny<HttpContent>(), It.IsAny<string>()))
        .ReturnsAsync(new HttpResponseMessage(HttpStatusCode.BadRequest));

    mockClient
        .Setup(repo => repo.SendAsync(It.IsAny<HttpRequestMessage>(), It.IsAny<string>()))
        .ThrowsAsync(new Exception("Some message here"));

    //Act 
    Func<Task> act = () => this._iADLS_Operations.CreateCSVFile(dtData, fileName);

    //Assert
    Exception ex = await Assert.ThrowsAsync<Exception>(act);
    Assert.Contains("Exception occurred while executing method:", ex.Message);
}

[事实]
公共异步任务CreateCSVFile_失败（）{
//安排
var dtData=新数据表（）；
字符串fileName=“”；
var mockClient=new Mock（）；
这是。_iADLS_Operations=新的ADLS_操作（mockClient.Object）；
模拟客户端
.Setup（repo=>repo.PostAsync（It.IsAny（），It.IsAny（），It.IsAny（））
.ReturnsAsync（新的HttpResponseMessage（HttpStatusCode.BadRequest））；
模拟客户端
.Setup（repo=>repo.sendsync（It.IsAny（），It.IsAny（））
.ThrowsAsync（新异常（“此处的某些消息”）；
//表演
Func act=（）=>this.\u iADLS\u Operations.CreateCSVFile（dtData，fileName）；
//断言
Exception ex=await Assert.ThrowsAsync（act）；
Contains（“执行方法时发生异常：”，例如Message）；
}

注意在设置中使用了Moq的

ReturnsAsync

和

ThrowsAsync

，以及xUnit的

Assert.ThrowsAsync

---

现在，您可以避免执行诸如

.Result

之类的阻塞调用，这可能会导致死锁。

抛出
而不是
返回
…感谢您的建议。当我遇到麻烦时，StackOverflow从不让我失望。极好的解释。问题解决了。
[Fact]
public async Task CreateCSVFile_Failure() {
    //Arrange
    var dtData = new DataTable();
    string fileName = "";
    var mockClient = new Mock<IHttpHandler>();

    this._iADLS_Operations = new ADLS_Operations(mockClient.Object);

    mockClient
        .Setup(repo => repo.PostAsync(It.IsAny<string>(), It.IsAny<HttpContent>(), It.IsAny<string>()))
        .ReturnsAsync(new HttpResponseMessage(HttpStatusCode.BadRequest));

    mockClient
        .Setup(repo => repo.SendAsync(It.IsAny<HttpRequestMessage>(), It.IsAny<string>()))
        .ThrowsAsync(new Exception("Some message here"));

    //Act 
    Func<Task> act = () => this._iADLS_Operations.CreateCSVFile(dtData, fileName);

    //Assert
    Exception ex = await Assert.ThrowsAsync<Exception>(act);
    Assert.Contains("Exception occurred while executing method:", ex.Message);
}