unit testing with junit
DESCRIPTION
Unit Testing with JUnit. Dan Fleck Spring 2010. What is Unit Testing?. A procedure to validate individual units of Source Code Example: A procedure, method or class Validating each individual piece reduces errors when integrating the pieces together later. Automated Unit Tests with JUnit. - PowerPoint PPT PresentationTRANSCRIPT
Unit Testing with JUnitDan Fleck
Spring 2010
What is Unit Testing?A procedure to validate
individual units of Source CodeExample: A procedure, method
or class Validating each individual piece
reduces errors when integrating the pieces together later
Automated Unit Tests with JUnitJunit is a unit testing
framework for Java Allows you to write unit tests
in Java using a simple interface
Automated testing enables running and rerunning tests very easily and quickly
An example unit test@Testpublic void testCellChangePropagates() {
Spreadsheet sheet = new Spreadsheet();
sheet.put("A1", "5"); sheet.put("A2", "=A1"); sheet.put("A1", "10");
assertEquals("10",sheet.get("A2")); }
Junit Assert During a test use Asserts to specify if the test passed or failed
org.junit.Assert – allows you to test if certain ideas hold by asserting results: http://junit.sourceforge.net/javadoc/
assertEquals(expected, actual) assertEquals(message, expected, actual) assertEquals(expected, actual, delta) assertEquals(message, expected, actual, delta) assertFalse(condition) assertFalse(message, condition) Assert(Not)Null(object) Assert(Not)Null(message, object) Assert(Not)Same(expected, actual) Assert(Not)Same(message, expected, actual) assertTrue(condition) assertTrue(message, condition)
Junit Methods – Java annotations @BeforeClass // Run before all tests in class public static void setUpClass() throws Exception {}
@AfterClass // Run after all tests in class public static void tearDownClass() throws Exception {}
@Before // Run before each test in class public void setUp() {}
@After // Run after each test in class public void tearDown() {}
@Test public void testMain() { http://www.cavdar.net/2008/07/21/junit-4-in-60-seconds/
Junit with Netbeans1. New File2. Choose file type: Junit3. Choose Test for Existing Class4. Junit test with all stubs
created for that class5. Fill in the individual tests6. Run Tests (Netbeans options)
Note: If this option doesn’t exist use New File->Other->Junit->Test for existing class
Junit Documentation/Tutorials http://junit.sourceforge.net/
http://code.google.com/p/t2framework/wiki/JUnitQuickTutorial
http://junit.sourceforge.net/doc/testinfected/testing.htm (older)
Lines of code coverage analysis
Determining which lines of code your tests have exercised and which they have not
Allows you to detect if your unit tests (or system tests) are adequately covering all possibilities or not
This is just one way to test
Lines of code coverage analysis with Netbeans• Install Unit Test Code
Coverage Viewer module• (See next slide for instructions)
• Write a Unit Test• Run test and view highlighted
code
Installing the Code Coverage Plugin Go into Netbeans -> Tools -> Plugins
Search for "Code Coverage" and install it.
If you don't see it in the list of available plugins, go to the "Settings" tab and check "Netbeans Beta”, reload the catalog, and then try again.
If you don't see Netbeans Beta in the list on Settings, add the following source for plugins:
Netbeans Beta
http://updates.netbeans.org/netbeans/updates/6.8/uc/final/beta/catalog.xml.gz
How do you you combine coverage with traditional system test scripts? Traditional system testing uses scripts- 1. Enter salary- 2. Enter number of dependents- 3. Click “Calculate Taxes” button- …
To combine this with coverage, launch the GUI while capturing coverage statistics
Run the test case to determine coverage
How to write test casesSee sample system test case
http://www.cs.gmu.edu/~kdobolyi/cs421/SAMPLESystemTestCase.doc
See sample unit test case http://www.cs.gmu.edu/~kdobolyi/cs421/
Main.java http://www.cs.gmu.edu/~kdobolyi/cs421/
Triangle.java http://www.cs.gmu.edu/~kdobolyi/cs421/
Triangle.java
SummaryUnit tests can help test the
details of your program Automated unit tests provide
constant visibility and easy retesting
Test coverage supplies valuable information when running both unit tests and system tests