Are for loops that test a condition OK in unit tests?

Question

I am starting to play around with xUnit and Moq and was wondering if I am doing it right.

Should I write tests like this:

[Fact]
public void ForWebShouldReturnDev()
{
    // Arrange
    var server = new Mock<HttpServerUtilityBase>();
    server.SetupSequence(s => s.MachineName).Returns("t11466").Returns("localhost").Returns("webdev");

    var context = new Mock<HttpContextBase>();
    context.SetupGet(c => c.Server).Returns(server.Object);

    var service = new EnvironmentService(context.Object, null);

    // Act / Assert
    service.GetApplicationEnvironment().Should().Be(ApplicationEnvironment.Dev);
    service.GetApplicationEnvironment().Should().Be(ApplicationEnvironment.Dev);
    service.GetApplicationEnvironment().Should().Be(ApplicationEnvironment.Dev);
}

Or more like this:

[Fact]
public void ForWebShouldReturnDev()
{
    // Arrange
    var server = new Mock<HttpServerUtilityBase>();

    var context = new Mock<HttpContextBase>();
    context.SetupGet(c => c.Server).Returns(server.Object);

    var service = new EnvironmentService(context.Object, null);

    // Act / Assert
    foreach (var name in new string[] { "t11466", "localhost", "webdev" })
    {
        server.Setup(s => s.MachineName).Returns(name);
        service.GetApplicationEnvironment().Should().Be(ApplicationEnvironment.Dev);
    }
}

I know you are only supposed to test one unit of code per test, but when there are variables to the test is it OK to loop through asserts?

I am having trouble figuring out the best way to test these types of things.

For the record, below is the actual code under test:

// The constructor for the application environment
public EnvironmentService(HttpContextBase httpContext, IEnvironment environment)
{
    this.environment = environment;
    this.httpContext = httpContext;
}

private readonly Dictionary<ApplicationEnvironment, string> applicationEnvironments = new Dictionary<ApplicationEnvironment, string>() {
    { ApplicationEnvironment.Dev, "DEV" },
    { ApplicationEnvironment.Test, "TEST" },
    { ApplicationEnvironment.QA, "QA" },
    { ApplicationEnvironment.Prod, "PROD" }
};

public ApplicationEnvironment GetApplicationEnvironment()
{
    var machine = IsWeb ? httpContext.Server.MachineName : environment.GetCommandLineArgs().First();

    return applicationEnvironments.FirstOrDefault(x => machine.ToUpper().Contains(x.Value)).Key;
}

I have another question out there here regarding more specifics with Moq.

Are there any good resources out there for Moq, their documentation is pretty thin.

score 1 · Accepted Answer · edited May 23 '17 at 10:34

1

If using NUnit I would personally use the [TestCase] attribute, that way you are still testing one thing but with a set of cases to test.

Something similar exists in xUnit, explained in this post in this SO post

edited May 23 '17 at 10:34

Community

1
1

answered Oct 31 '12 at 11:26

Steven Mortimer

113
4

Are for loops that test a condition OK in unit tests?

1 Answers1