Coverage Testing

Adam Myatt, Sang Shin, sang.shin@sun.com, www.javapassion.com/javaprogrammingadv

In this lab, you are going to exercise basic features of NetBeans code coverage plug-in. The code coverage must be enabled for each project by invoking the Coverage | Activate Coverage Collection action from the project node's context menu. Then, as unit tests are run, the plug-in will update the code coverage data and markup the editor's lines accordingly. The lines which are fully covered by unit tests are annotated with green color in java editor and the line covered partially are annotated in yellow. The colors can be modified in Tools | Options | Fonts & Colors | Annotations. Reports are also supported. You can view coverage reports for your project by clicking YOUR_PROJECT_NODE->Coverage->Show Project Coverage Statistics menu item.

Expected duration: 60 minutes (not including time for homework)

Software Needed

Before you begin, you need to install the following software on your computer.

Java Standard Development Kit (JDK™) version 5.0 (download) or 6.0 (download)

Select JDK 6 Update x from the download page

NetBeans IDE 6.0 (download)

Download either "Web & Java EE" or "All" bundles.

NetBeans code coverage plug-in.

For your convenience, it is included in the hands-on lab zip file under <LAB_UNZIPPED_DIRECTORY>/javatestcodecoverage/netbeansplugin directory.

1078_javatestcodecoverage.zip (download)

The zip file contains this document and the lab contents.
Download it and unzip in a directory of your choice.

Change Log

March 14th, 2008: Created

Lab Exercises

Exercise 0: Install NetBeans code coverage plug-in
Exercise 1: Do coverage testing on Java classes (30 minutes)
Exercise 2: Do coverage testing on Anagram application (30 minutes)
Homework Exercise (for people who are taking Sang Shin's "Advanced Java Programming online course")

Exercise 0: Install NetBeans code coverage plug-in

1. Select Tools from top-level menu and select Plugins.

Figure-0.11: Select Plugins

2. Select Downloaded tab and click Add Plugins button.

Figure-0.12: Add plugins

3. Browse down to <LAB_UNZIPPED_DIRECTORY>/javatestcodecoverage/netbeansplugin directory and select both nbm files and click Open.

Figure-0.13: Select plugins

4. Check both EMMA and Code Coverage Plugin and click Install.

Figure-0.14: Install the plugins

5. Click Next.

Figure-0.15: Install plugins

6. Check "I accept the terms .." and click Install.

Figure-0.16: Accept licensing terms

7. Click Continue.

Figure-0.17: Validation warning

8. Follow the remaining instructions as mentioned.

Exercise 1: Do coverage testing (using standalone codecoverage application)

In this exercise, you are going to perform a simple code-coverage testing on a simple class. This exercise is based on the Reviewing the NetBeans Unit Tests Code Coverage Plugin article by Adam Myatt.

Create a new project
Create JUnit test
Perform coverage testing
Add another class to the project
Create JUnit test on the newly created class
Perform coverage testing on the newly created class
Display coverage statistics

(1.1) Create a new project

1. Create a new project.

Select File from top level menu items and select New Project.

Figure-1.11: Create a new project

Select Java under Categories and Java Class Library under Projects.
Click Next.

Figure-1.12: Ceate Java Class Library project

Click Finish.

Figure-1.13: Give a project a name

2. Add a new Java class.

Right click project node and select New->Java Class.

Figure-1.14: Create a new Java class

Observe that the New Java Class dialog box appears.
For the Class Name field, enter StringUtils.
For the Package field, enter mypackage (or whatever package name you want to give).
Click Finish.

Figure-1.15: Give a name to the new Java class

3. Modify the IDE generated code with the code below.

package mypackage;

/**
*
* @author sang
*/
public class StringUtils {

    public static String tryIntToString(int numLoops) {

        StringBuffer sb = new StringBuffer();

        for (int i = 0; i < numLoops; i++) {
            sb.append(String.valueOf(i));
        }
        return sb.toString();
    }
}

Code-1.16: Modified StringUtils.java

Figure-1.17: Modified StringUtils.java

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(1.2) Create JUnit test

1. Create JUnit test.

Right click StringUtils.java and select Tools->Create JUnit Tests.

Figure-1.21: Create JUnit test

Select JUnit 4.x (if it has not been selected already).
Click Select button.

Figure-1.22: Choose JUnit 4.x

Observe that Create Tests dialog appears.
Click OK accepting defaults values.

Figure-1.23: Create Tests

Modify the IDE generated testing code as shown below.

package mypackage;

import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;

/**
*
* @author sang
*/
public class StringUtilsTest {

    public StringUtilsTest() {
    }

    @BeforeClass
    public static void setUpClass() throws Exception {
    }

    @AfterClass
    public static void tearDownClass() throws Exception {
    }

    @Before
    public void setUp() {
    }

    @After
    public void tearDown() {
    }

    @Test
    public void testTryIntToString() {
        System.out.println("tryIntToString03");

        int numLoops = 10000;
        String result = StringUtils.tryIntToString(numLoops);
        int expectedResult = 38890;
        assertEquals(expectedResult, result.length());
    }
}

Code-1.24: Modified StringUtilsTest.java

Figure-1.25: Modified StringUtilsTest.java

2. Perform the JUnit test.

Right click the project node and select Test.

Figure-1.26: Do the test

Observe that the test passed.

Figure-1.27: See the testing result

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(1.3) Perform coverage testing

1. Activate the coverage testing.

Right click project node and select Coverage->Activate Coverage Collection.

Figure-1.31: Activate Coverage Collection

2. Run the JUnit test.
3. Observe the coverage testing in the StringUtils.java.

Open StringUtils.java.
Observe the lines of code that were executed are highlighted with light green colored shade.

Figure-1.32: Observe the coverage

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(1.4) Add another target class

1. Create another Java class called StringUtils1.java.
2. Modify the IDE generated StringUtils1.java as shown below.

package mypackage;

/**
*
* @author sang
*/
public class StringUtils1 {

    public static String tryIntToString(int numLoops) {

        StringBuffer sb = new StringBuffer(numLoops);

        if (numLoops > 10000) {
            sb.append("greater than 10000");
        } else {
            for (int i = 0; i < numLoops; i++) {
                sb.append(String.valueOf(i));
            }
        }

        return sb.toString();
    }
}

Code-1.41: Modified StringUtils1.java

Figure-1.42: Modified StringUtils1.java

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(1.5) Create JUnit test for the newly created class

1. Create JUnit test for the StringUtils1.java.

Figure-1.51: Create JUnit test

2. Modify the IDE generated Junit testing code as shown below.

package mypackage;

import org.junit.After;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import static org.junit.Assert.*;

/**
*
* @author sang
*/
public class StringUtils1Test {

    public StringUtils1Test() {
    }

    @BeforeClass
    public static void setUpClass() throws Exception {
    }

    @AfterClass
    public static void tearDownClass() throws Exception {
    }

    @Before
    public void setUp() {
    }

    @After
    public void tearDown() {
    }

    /**
     * Test of tryIntToString method, of class StringUtils1.
     */
    @Test
    public void tryIntToString() {
        System.out.println("tryIntToString");

        int numLoops = 10000;
        String result = StringUtils1.tryIntToString(numLoops);
        int expectedResult = 38890;
        assertEquals(expectedResult, result.length());
    }

}

Code-1.52: Modified StringUtils1Test.java