How to unit test the error message of a Conflict response in Web API

Question

Here is my endpoint:

public IHttpActionResult Work()
{
    try
    {
        this.Service.DoWork();
        return this.Ok();
    }
    catch (SomeException)
    {
        return this.Content(HttpStatusCode.Conflict, new { Message = "The message" });
    }
}

How can I unit test the error message?

Here is a test template:

[Test]
public void Work_Conflict()
{
    this.Service.Setup(x => x.DoWork()).Throws<SomeException>();
    var result = (<what goes here?>)this.MyController.Work();
    Assert.AreEqual("The message", <what goes here?>);
}

Answer 1

You were almost there.

You need to cast the result to the actual types returned from the ApiController and extract the expected data.

[Test]
public void Work_Conflict()
{
    this.Service.Setup(x => x.DoWork()).Throws<SomeException>();
    IHttpActionResult result = this.MyController.Work();
    var objectResult = result as ObjectResult;
    Assert.IsNotNull(objectResult);
    dynamic model = objectResult.Value;
    string actual = (string)model.Message;
    string expected = "The message";
    Assert.AreEqual(expected, actual);
}

Answer 2

Try this: where BadRequestObjectResult comes from the Microsoft.AspNetCore.Mvc namespace

    public void Work_Conflict()
    {
        //Arrange

        this.Service.Setup(x => x.DoWork()).Throws<SomeException>();

        using (var controller = new MyController()) ;

        //Act
        var result = MyController.Work();
        var badRequest = result as BadRequestObjectResult;

        //Assert
        var conflictCode = 0;
        Assert.AreEqual(conflictCode, badRequest.StatusCode);
        Assert.AreEqual("The message", badRequest.Value);

    }