Software System Testing

Writing Unit Tests Using White-Box Testing Approach and JUnit Tool

---

Materials:

• NetBeans IDE 8.2
• JDK 8
• 07 Software System for Testing folder
  • LoginModule.zip

---

Procedure:

1. Create a folder on your local drive with your name. (Ex. Jess_Diaz)
2. Open NetBeans IDE 8.2. Go to File > New Project. The New Project dialog box will appear. Select Java in Categories > Java Application in Projects. Then, click the Next button.
3. Write TaxCalculator in Project Name and check the Use Dedicated Folder for Storing Libraries option. Click Finish to create the project.
4. Go to File > New File. The New File dialog box will appear. Select Java in Categories > Java Class in File Types. Then, click the Next button.
5. Write ItemTaxCalculator in Class Name and select taxcalculator in Package. Click Finish to create the new class.
6. Write the following program in the ItemTaxCalculator class. The CalculateItemTax method will be used to calculate an item sales tax.

package taxcalculator;

public class ItemTaxCalculator {
      public double CalculateItemTax (double itemPrice, double taxPercent) {
            double decrease = taxPercent / 10.0;
            return itemPrice * decrease;
      }
}

7. Write a unit test using the JUnit unit testing tool available for NetBeans IDE. This unit test will be used to test the CalculateItemTax method.
8. Go to File > New File. The New File dialog box will appear. Select Unit Tests in Categories > JUnit Test in File Types. Then, click the Next button.

Note

If the JUnit Test is not installed in your IDE, go to Tools > Plugins. The Plugins dialog box will appear. Go to the Available Plugins tab and look for the Search textbox. Type JUnit. Check JUnit in the result area and click Install.

9. Write ItemTaxCalculatorTest in the Class name and write the package name taxcalculator in Package. Tick all the checkbox options in Generated Code and Generated Comments. Click Finish to create the unit test class and the Test Packages node.

Note

• When creating the unit test class, it is best to write the class name the same as the class (unit) to be tested and; word "Test" should be affixed to the class name.
• The project requires a separate directory for the Test Packages to create tests. This directory will contain the unit tests for the project.
• The package of class to be tested and the test class should be the same.

10. Go to the Projects directory to view the project. Your project directory for the current project should be the same as Figure 1.

Figure 1. TaxCalculator project

11. To execute a test, go to Projects. Right-click the class file to test, which is the ItemTaxCalculator, then select Test File. This will run a test to the project but will result to Failed (see Figure 2). This is because there are no runnable test methods found in the test class.

Figure 2. Test failed shown in Test Results window

12. To create a test method in the test class, write the following test method inside the ItemTaxCalculatorTest class:

// Test of CalculateItemTax method, of ItemTaxCalculator class

@Test
public void testCalculateItemTax() {
      System.out.println("CalculateItemTax method");
      ItemTaxCalculator instance = new ItemTaxCalculator ();
      double itemPrice = 50.0;
      double taxPercent = 1.0;
      double expectedResult = 5.0;
      double result = instance.CalculateItemTax(itemPrice, taxPercent);
      assertEquals(expectedResult, result, 0.0);
}

13. Run the Test File again to run the unit test, This should result to Passed (see Figure 3).

Figure 3. Test passed shown in Test Results window

• In the given test program, the method CalculateItemTax() is being tested.
• The test method testCalculateItemTax() contains the annotation @Test. This annotation specifies that method is the test method.
• Within the test method, the instance of ItemTaxCalculator class is created. This will be used to call the method to be tested.
• The test method contains test inputs, itemPrice and taxPercent, and the variable expectedResult that will hold the expected output of the test from the test data.
• The variable result will hold the actual result of the test and will be used to compare to the expected result. This variable will hold the result from the method of the created instance.
• The assertEquals() method belongs to the org.junit.Assert class. This method checks if the given expected result is equal to the actual result. This method is overloaded.

Note

If you run the program before executing the test, it is necessary to Clean and Build () the program before executing the test.

---

Activity:

1. Using NetBeans IDE, extract and open the java zipped project LoginModule in 07 Software System for Testing folder. This project contains functions that allow users to log in to and create an account for the system. This also has functions that will compute basic salary based on hourly rate, hours worked, and overtime.
2. Create unit tests for the following classes of the system that will result all into “passed”:

• VerifyUserLogin
• PayrollCalculator

---

🖥️ Final Laboratory Exercise for my 3rd-year college course "Application Development and Emerging Technologies."

SY2324-1T

💙 Instagram: @izzyluuuuh