How to mock SendGrid

Question

I am trying to write a unit test for a method I wrote which sends out an email with SendGrid. My method is something like this:

public async Task SendEmail(TemplatedMailMessage emailMessage)
{
    if (String.IsNullOrWhiteSpace(emailMessage.Html) || String.IsNullOrWhiteSpace(emailMessage.From.ToString()) || !emailMessage.To.Any())
    {
        throw new Exception("Html, From or To is empty");
    }

    try
    {
        // Send the email
        await this.TransportWeb.DeliverAsync(emailMessage.GetSendGridMessage());
    }
    catch (Exception ex)
    {
        //do stuff
    }

    //log success
}

the TransportWeb is a property which is set in my constructor through a parameter so I can create a mock object.

public EmailManager(Web transportWeb = null)
{
    this.TransportWeb = transportWeb ?? SetupSendGrid();
}

In my test method I am trying to mock the TransportWeb (of type SendGrid.Web) property:

    [TestMethod]
    public async Task SendEmail_ValidEmailTemplateAndNoParameters_EmailIsSent()
    {
        //ARRANGE
        var templatedMailmessage = new Mock<TemplatedMailMessage>();
        var transportWeb = new Mock<Web>();
        transportWeb.SetupAllProperties();
        transportWeb.Setup(x => x.DeliverAsync(It.IsAny<ISendGrid>()));
        var emailManager = new EmailManager(transportWeb.Object);

        //ACT
        await emailManager.Send(templatedMailmessage.Object);

        //ASSERT
        transportWeb.Verify(x => x.DeliverAsync(It.IsAny<ISendGrid>()), Times.Once());
    }

However, I get the following error:

Invalid setup on a non-virtual (overridable in VB) member: x => x.DeliverAsync

Does anybody have an idea how I can fix this?

Answer 1

Okay I fixed it :)

You should not use the Web class but ITransport interface:

var transport = new Mock<ITransport>();
transport.SetupAllProperties();
transport.Setup(x => x.DeliverAsync(It.IsAny<SendGridMessage>())).ReturnsTask();

var em = new EmailManager(transport.Object);

I also used the extensions methods created by Simon V.