Unit Testing with JUnit

1. Unit Testing with JUnit Dan Fleck Fall 2007 (For both CS211 and 421… two birds… one lecture! :-)

2. 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

3. Automated Unit Tests with JUnit • Junit 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

4. An example unit test public void testCellChangePropagates() { Spreadsheet sheet = new Spreadsheet(); sheet.put("A1", "5"); sheet.put("A2", "=A1"); sheet.put("A1", "10"); assertEquals("10",sheet.get("A2")); }

5. Junit with Netbeans • New File • Choose file type: Junit • Choose Test for Existing Class • Junit test with all stubs created for that class • Fill in the individual tests • Run Tests (Netbeans options)

6. 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

7. Coverage Analysis with Netbeans • Install Unit Test Code Coverage Viewer module • Write a Unit Test • Run test and view highlighted code

8. A simple test to dynamically cover your code: public void testMain() { SuDoku sFrame = new SuDoku(); while (sFrame.isDisplayable()) { try { Thread.sleep(100); } catch (Exception e) { e.printStackTrace(); } } Assert.assertEquals(true,true); }

9. How to write test cases • See sample system test case • See sample unit test case

10. Class Exercise - Lets try it out! • Using the SystemRequirementsSpecificationExample.doc • Each team pick a use case • Document the overall system or unit tests you would write to test • Do the same for a non-functional requirement (sec 5)

11. Summary • Unit 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