Unit testing in Visual Studio 2008 Team System - part IV

Next (maybe not last) part re units tests inside VS.

[Ignore()]

Useful if one of test methods failed – you can use [Ignore()] attribute to decide later what to do with that test

So, our complete class code looks now as follow:

<br /> <br /> <br /> <br /> <br /> <br /> <br />using bank; <br />using Microsoft.VisualStudio.TestTools.UnitTesting; <br />namespace UnitTests <br />{ <br /> <br /> <br /> /// <summary> <br /> ///This is a test class for AccountTest and is intended <br /> ///to contain all AccountTest Unit Tests <br /> ///</summary> <br /> [TestClass ()] <br /> public class AccountTest { <br /> <br /> <br /> private TestContext testContextInstance; <br /> <br /> /// <summary> <br /> ///Gets or sets the test context which provides <br /> ///information about and functionality for the current test run. <br /> ///</summary> <br /> public TestContext TestContext { <br /> get { <br /> return testContextInstance; <br /> } <br /> set { <br /> testContextInstance = value; <br /> } <br /> } <br /> <br /> /// <summary> <br /> ///A test for TransferFunds <br /> ///</summary> <br /> [TestMethod ()] <br /> [ExpectedException(typeof(InsufficientFundsException))] <br /> public void TransferFundsTest() { <br /> Account source = new Account (); <br /> source.Deposit(200F); // source.Ballance = 200 <br /> <br /> Account destination = new Account(); <br /> destination.Deposit(150F); // destination.Ballance = 150 <br /> <br /> // Call tested method <br /> source.TransferFunds ( destination, 195F ); <br /> // source.Ballance = 200 - 100 = 100; <br /> // destination.Ballance = 150 + 100 = 250; <br /> <br /> // Perform checks <br /> Assert.AreEqual( 250F, destination.Balance); // OK <br /> Assert.AreEqual( 100F, source.Balance); // OK <br /> <br /> // No exception thrown - test failed <br /> } <br /> <br /> [TestMethod ()] <br /> [Ignore()] <br /> public void TransferWithInsufficientFundsAtomicity() { <br /> Account source = new Account (); <br /> source.Deposit(200F); // source.Ballance = 200 <br /> <br /> Account destination = new Account(); <br /> destination.Deposit(150F); // destination.Ballance = 150 <br /> <br /> try { <br /> // Call tested method <br /> source.TransferFunds ( destination, 300F ); <br /> // source.Ballance = 200 - 300 = -100; -> exceptin thrown <br /> // destination.Ballance = 150 + 300 = 450; <br /> } <br /> catch (InsufficientFundsException expected) { <br /> // source balance less than 10F - exception catch here... <br /> } <br /> <br /> // Balances will not change as Exception thrown <br /> <br /> // Perform checks <br /> Assert.AreEqual( 200F, source.Balance); // OK <br /> Assert.AreEqual( 150F, destination.Balance); // OK <br /> <br /> // No exception thrown - test failed <br /> } <br /> } <br />} <br /> <br /> <br /> <br /> <br /> <br /> public void TransferFunds ( Account destination, float amount ) { <br /> // Throw exception if minimum ballance exceeded <br /> if (balance-amount< 10F ) throw new InsufficientFundsException(); <br /> <br /> destination.Deposit(amount); // ++ <br /> Withdraw(amount); // -- <br /> <br /> } <br /> <br />

Refactoring

If we look at above code we can see lot of code duplication – refactoring is necessary.

We can appoint common block of code, it is worth to split tests on small 1 function methods.

To achieve that we will:

• Define local members (source + destination)
• Add Init() method marked by attribute [TestInitialize()] – executed before each tests
  (please note method need to be public)
• Break down test methods on 3 atomic methods

After all our code shall look as follow:

<br /> <br />using bank; <br />using Microsoft.VisualStudio.TestTools.UnitTesting; <br />namespace UnitTests <br />{ <br /> <br /> <br /> /// <summary> <br /> ///This is a test class for AccountTest and is intended <br /> ///to contain all AccountTest Unit Tests <br /> ///</summary> <br /> [TestClass ()] <br /> public class AccountTest { <br /> private TestContext testContextInstance; <br /> /// <summary> <br /> ///Gets or sets the test context which provides <br /> ///information about and functionality for the current test run. <br /> ///</summary> <br /> public TestContext TestContext { <br /> get { <br /> return testContextInstance; <br /> } <br /> set { <br /> testContextInstance = value; <br /> } <br /> } <br /> <br /> Account source; <br /> Account destination; <br /> <br /> /// <summary> <br /> /// Initializes each tests in class <br /> /// </summary> <br /> [TestInitialize()] <br /> public void Init() { <br /> // COnstruct 2 objects <br /> source = new Account(); <br /> destination = new Account(); <br /> <br /> source.Deposit(200F); // source.Ballance = 200 <br /> destination.Deposit(150F); // destination.Ballance = 150 <br /> } <br /> <br /> <br /> /// <summary> <br /> ///A test for TransferFunds <br /> ///</summary> <br /> [TestMethod ()] <br /> public void TransferFundsTest() { <br /> // Call tested method <br /> source.TransferFunds ( destination, 100F ); <br /> // source.Ballance = 200 - 100 = 100; <br /> // destination.Ballance = 150 + 100 = 250; <br /> <br /> // Perform checks <br /> Assert.AreEqual( 100F, source.Balance); // OK <br /> Assert.AreEqual( 250F, destination.Balance); // OK <br /> } <br /> <br /> /// <summary> <br /> ///A test for TransferFunds <br /> ///</summary> <br /> [TestMethod ()] <br /> [ExpectedException(typeof(InsufficientFundsException))] <br /> public void TransferFundsMinBallanceExceededTest() { <br /> // Call tested method <br /> source.TransferFunds ( destination, 195F ); <br /> // source.Ballance = 200 - 195 = 5; <br /> // destination.Ballance = 150 + 195 = 345; <br /> <br /> // Exception need be thrown <br /> } <br /> <br /> [TestMethod ()] <br /> public void TransferWithInsufficientFundsAtomicity() { <br /> try { <br /> // Call tested method <br /> source.TransferFunds ( destination, 300F ); <br /> // source.Ballance = 200 - 300 = -100; -> exceptin thrown <br /> // destination.Ballance = 150 + 300 = 450; <br /> } <br /> catch (InsufficientFundsException expected) { <br /> // source balance less than 10F - exception catch here... <br /> } <br /> <br /> // Balances will not change as Exception thrown <br /> <br /> // Perform checks <br /> Assert.AreEqual( 200F, source.Balance); // OK <br /> Assert.AreEqual( 150F, destination.Balance); // OK <br /> <br /> // No exception thrown - test failed <br /> } <br /> } <br />} <br /> <br /> <br />