Developing For .NET

I’ve read about Unit Testing and Test Driven Development (TDD) but have never attempted to use it or even really understand it. I recently became intrigued by it watching Rob Conery’s excellent video series. Today I began putting the final touches on the Authorize.Net code I am going to release, so I thought this would be a good opportunity to try some testing.

I have never done any Unit Testing, and even though I wasn’t sure where to start, I figured it out pretty quickly. First things first, I added a Test Project to my solution. This created all the necessary framework code as one might expect. I deleted the default TestMethod and began adding TestMethods of my own, intuitively marked with the [TestMethod] attribute. A little Google hopping and I quickly learned about Assert.xxx() methods.

When it came time to actually run the tests, I was a little stumped. I read where you could right click the method name and execute “Run Tests”, but it seems to only run one at a time. In the test results window, there is a button for “Run All test”, but it too only ran the last executed test. Finally, I changed the Test project to my Solution Start Project, and pressing F5 to execute will run all the tests.

Here is the code from my first stab at it:

using System;
using System.Text;
using System.Collections.Generic;
using System.Linq;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using DevelopingForDotNet.AuthorizeNet;

namespace TestAuthorizeNet
{
    ///
    /// Summary description for UnitTest1
    ///
    [TestClass]
    public class UnitTest1
    {
        public UnitTest1()
        {
            //
            // TODO: Add constructor logic here
            //
        }

        private TestContext testContextInstance;

        ///
        ///Gets or sets the test context which provides
        ///information about and functionality for the current test run.
        ///
        public TestContext TestContext
        {
            get
            {
                return testContextInstance;
            }
            set
            {
                testContextInstance = value;
            }
        }

        #region Additional test attributes
        //
        // You can use the following additional attributes as you write your tests:
        //
        // Use ClassInitialize to run code before running the first test in the class
        // [ClassInitialize()]
        // public static void MyClassInitialize(TestContext testContext) { }
        //
        // Use ClassCleanup to run code after all tests in a class have run
        // [ClassCleanup()]
        // public static void MyClassCleanup() { }
        //
        // Use TestInitialize to run code before running each test
        // [TestInitialize()]
        // public void MyTestInitialize() { }
        //
        // Use TestCleanup to run code after each test has run
        // [TestCleanup()]
        // public void MyTestCleanup() { }
        //
        #endregion

        [TestMethod]
        public void TestCreditCardNumberWithCharactersConvertedToJustNumbers()
        {
            TransactionRequestInfo req = new TransactionRequestInfo();
            string testValue = "1234-5678-9012-3456";
            req.CardNumber = testValue;
            Assert.AreEqual("1234567890123456", req.CardNumber);
        }

        [TestMethod]
        public void TestZipCodeNotNumericThrowsArgumentException()
        {
            TransactionRequestInfo req = new TransactionRequestInfo();
            string testValue = "034JB";
            try
            {
                req.Zip = testValue;
                Assert.Fail("Exception not thrown.");
            }
            catch (ArgumentException aex)
            {
                Assert.IsTrue(true, "Exception Thrown Properly");
            }
        }

        [TestMethod]
        public void TestZipCodeNumericButGreaterThan99999()
        {
            TransactionRequestInfo req = new TransactionRequestInfo();
            string testValue = "58634789";
            try
            {
                req.Zip = testValue;
                Assert.Fail("Exception not thrown.");
            }
            catch (ArgumentException aex)
            {
                Assert.IsTrue(true, "Exception Thrown Properly");
            }
        }

        [TestMethod]
        public void TestZipCodeValidReturnsLeadingZeros()
        {
            TransactionRequestInfo req = new TransactionRequestInfo();
            string testValue = "586";
            req.Zip = testValue;
            Assert.AreEqual("00586", req.Zip);
        }
    }
}

A few notes worth mentioning:

1. I found a bunch of sites that talked about Testing in Visual Studio, about half and half claiming it was a good thing. What I did not find so readily was a good tutorial. I did finally come across a good post at http://www.geekzone.co.nz/vs2008/4819, a blog I had never visited before.
2. What I have done so far would certainly not qualify as TDD, I’m just experimenting at this phase. I did, however, try to write tests that failed before correcting them to pass, but they were all on pre-existing methods.
3. I tried to follow the “use long, descriptive test method names” rule.
4. I need to understand mocking. Right now, I am creating full fledged class instances.
5. It seems a tad slow. I can’t imagine what this would be like with hundreds of tests to run. I’m sure there are ways to handle this issue.

My plan is to include the test Project along with the entire Authorize.Net Solution. Whether it will be helpful or not, I don’t really know.