单元测试采用参数的 WebAPI 控制器

Question

I have a WebAPI controller that takes a parameters object like this:

public class InvoicesParameters : QueryStringParameters
{
    public string InvoiceType { get; set; } = "P";
    public bool Approved { get; set; } = false;
    public string Region { get; set; } = null;
    public string VendorCode { get; set; } = null;
}

The controller works just fine. I can pass any or all of the params and get the expected results. Now I am trying to add a unit test for this controller using xUnit. I've tried several different methods all with various failing results.

My test looks like this:

[Theory(DisplayName = "Get Invoices")]
[ClassData(typeof(InvoicesParametersTestData))]
public void GetInvoices_ShouldReturnInvoices(InvoicesParameters iparams)
{
    var mockService = new Mock<IShopAPService>();
    mockService.Setup(x => x.GetInvoices(iparams))
        .Returns(GetSampleInvoices());

    var controller = new InvoicesController(mockService.Object);

    IHttpActionResult actionResult = controller.GetInvoices(iparams);
    var contentResult = actionResult as OkNegotiatedContentResult<List<Invoice>>;

    Assert.NotNull(contentResult);
    Assert.NotNull(contentResult.Content);
    Assert.Equal(3, contentResult.Content.Count);
}

private List<InvoiceDto> GetSampleInvoices()
{
    List<InvoiceDto> output = new List<InvoiceDto>
    {
        new InvoiceDto
        {
            Id = 1,
            VendorCode = "PFSATL",
            VendorName = "PlantStone LLC",
            Type = "I",
            PONumber = "54P-00007365",
            OrderId  = "940817",
            InvoiceType = "P",
            InvoiceNumber = "DT1010816950",
            InvoiceDate = Convert.ToDateTime("01/01/2020"),
            InvoiceAmount = 2496.48M,
            Region = "WEST",
            ShopNumber = "16",
            ApprovalDate = null,
            Approver = null
        },
        new InvoiceDto
        {
            Id = 2,
            VendorCode = "NATSLC",
            VendorName = "National American Doodads",
            Type = "I",
            PONumber = "72P-00004838",
            OrderId  = "874566",
            InvoiceType = "P",
            InvoiceNumber = "123454321789",
            InvoiceDate = Convert.ToDateTime("01/01/2020"),
            InvoiceAmount = 457.88M,
            Region = "WEST",
            ShopNumber = "16",
            ApprovalDate = null,
            Approver = null
        },
        new InvoiceDto
        {
            Id = 3,
            VendorCode = "BRIDG",
            VendorName = "Bridgeport Soda",
            Type = "I",
            PONumber = "54P-0074865",
            OrderId  = "741258",
            InvoiceType = "P",
            InvoiceNumber = "987456",
            InvoiceDate = Convert.ToDateTime("01/01/2020"),
            InvoiceAmount = 74.99M,
            Region = "WEST",
            ShopNumber = "16",
            ApprovalDate = null,
            Approver = null
        }
    };

    return output;
}


public class InvoicesParametersTestData
{
    public static IEnumerable<InvoicesParameters> TestData
    {
        get
        {
            yield return new InvoicesParameters { InvoiceType = "P", Approved = false };
            yield return new InvoicesParameters { InvoiceType = "P", Approved = true };
        }
    }
}

Something is not right with this pattern. I am getting a compile time error of ClassData must point to a valid class. Is there a better way to do this? or a way to fix what I have?

Answer 1

Your InvoicesParametersTestData class should look like this to make it work:

public class InvoicesParametersTestData : IEnumerable<object[]>
{
    private readonly List<object[]> _testData = new List<object[]>
    {
        new object[]
        {
            new InvoicesParameters
            {
                InvoiceType = "P", Approved = false
            },
            new InvoicesParameters
            {
                InvoiceType = "P",
                Approved = true
            }
        }
    };

    public IEnumerator<object[]> GetEnumerator() => _testData.GetEnumerator();

    IEnumerator IEnumerable.GetEnumerator() => GetEnumerator();
}

To be able to use a class with the DataClass attribute, the class has to inherit from IEnumerable<object[]> . The specified type has to be an object , otherwise xUnit will throw an error.

Because you are implementing IEnumerable , you also have to implement the GetEnumerator() methods.

EDIT

The error The test method expected 1 parameter value, but 2 parameter values were provided. is caused by _testData in class InvoicesParametersTestData which returns 2 items. To fix that, your test method should accept two parameters. Like: GetInvoices_ShouldReturnInvoices(InvoicesParameters iparams, InvoicesParameters iparams2) .

But , this would make for an odd test.

A better way of setting this up, is by using the InlineData attribute:

[Theory(DisplayName = "Get Invoices")]
[InlineData(true)]
[InlineData(false)]
public void GetInvoices_ShouldReturnInvoices(bool approved)
{
    var iparams = new InvoicesParameters
    {
        InvoiceType = "P",
        Approved = approved
    };

    var mockService = new Mock<IShopAPService>();
    mockService.Setup(x => x.GetInvoices(iparams))
        .Returns(GetSampleInvoices());

    var controller = new InvoicesController(mockService.Object);

    IHttpActionResult actionResult = controller.GetInvoices(iparams);
    var contentResult = actionResult as OkNegotiatedContentResult<List<Invoice>>;

    Assert.NotNull(contentResult);
    Assert.NotNull(contentResult.Content);
    Assert.Equal(3, contentResult.Content.Count);
}

You won't need the InvoicesParametersTestData class anymore.

If you would want to make InvoiceType variable as well, you could do it like this:

[InlineData(true, "P")]
[InlineData(false, "X")]
public void GetInvoices_ShouldReturnInvoices(bool approved, string invoiceType)