JUnit SWE 619 Summer 2007

July 18, 2007 SWE 619 (c) Aynur Abdurazik 2 What is JUnit? Open source Java testing framework used to write and run repeatable automated tests JUnit features include:  Assertions for testing expected results  Test fixtures for sharing common test data  Test suites for easily organizing and running tests  Graphical and textual test runners

July 18, 2007 SWE 619 (c) Aynur Abdurazik 3 JUnit Architecture

July 18, 2007 SWE 619 (c) Aynur Abdurazik 4 Test Scenarios with JUnit Used to test  A whole object  Part of an object - a method or some interacting methods  Interaction between several objects A test case represents one scenario  A tester class contains more than one scenario  Each senario is written into one test method

July 18, 2007 SWE 619 (c) Aynur Abdurazik 5 Writing Tests for JUnit Need to use the methods of the junit.framework.assert class  javadoc gives a complete description of its capabilities Each of these methods checks some condition and reports back to the test runner whether the test failed or succeeded. The test runner uses the result to update the display. All of the methods return void (i.e. they are procedures)

July 18, 2007 SWE 619 (c) Aynur Abdurazik 6 Writing Tests for JUnit – (cont’d) A few representative methods of junit.framework.assert  assertTrue(boolean)  assertTrue(String, boolean)  assertEquals(Object, Object)  assertNull(Object)  fail(String)

July 18, 2007 SWE 619 (c) Aynur Abdurazik 7 Sample Assertions (cont’d) static void assertEquals(boolean expected, boolean actual) Asserts that two booleans are equal.assertEquals static void assertEquals(byte expected, byte actual) Asserts that two bytes are equal.assertEquals static void assertEquals(char expected, char actual) Asserts that two chars are equal.assertEquals static void assertEquals(double expected, double actual, double delta) Asserts that two doubles are equal concerning a delta.assertEquals static void assertEquals(float expected, float actual, float delta) Asserts that two floats are equal concerning a delta.assertEquals static void assertEquals(int expected, int actual) Asserts that two ints are equal.assertEquals For a complete list, see 

July 18, 2007 SWE 619 (c) Aynur Abdurazik 8 How to write test case Two different ways for junit versions 3.X and 4.x. In Junit 3.X  1) import junit.framework.* 2) extend TestCase.  3) name the test methods with a prefix of ‘test’  4) validate conditions using one of the several assert methods

July 18, 2007 SWE 619 (c) Aynur Abdurazik 9 How to write test case (cont’d) In Junit 4.0 and later:  Do not extend from Junit.framework.TestCase  Do not prefix the test method with ‘test’  Use one of the assert methods  Run the test using JUnit4TestAdapter

July 18, 2007 SWE 619 (c) Aynur Abdurazik 10 Simple Example public class Math { static public int add(int a, int b) { return a + b; } }

July 18, 2007 SWE 619 (c) Aynur Abdurazik 11 Example JUnit test case import junit.framework.*; public class TestMath extends TestCase { public void testAdd() { int num1 = 3; int num2 = 2; int total = 5; int sum = 0; sum = Math.add(num1, num2); assertEquals(sum, total); } }

July 18, 2007 SWE 619 (c) Aynur Abdurazik 12 Testing the Stack class public class Stack{ public String toString() { // EFFECTS: Returns the String representation of this Stack from the // top to the bottom. StringBuffer buf = new StringBuffer("{"); for (int i = size-1; i >= 0; i--) { if (i < (size-1)) { buf.append(", "); } buf.append(elements[i].toString()); } buf.append("}"); return buf.toString(); } public boolean repOk() { if (elements == null) return false; if (size != elements.length) return false; for (int i = 0; i < size; i++) { if (elements[i] == null) return false; } return true; }

July 18, 2007 SWE 619 (c) Aynur Abdurazik 13 TestCases with JUnit 4.X for Stack Necessary classes to be imported: import org.junit.After; import org.junit.Before; import org.junit.Test; import static org.junit.Assert.assertEquals; import junit.framework.JUnit4TestAdapter;

July 18, 2007 SWE 619 (c) Aynur Abdurazik 14 TestCases with JUnit (Cont’d) public class StackTest { private Stack stack; /** * setUp method annotation. * Method can be named anything. public void runBeforeEachTest(){ stack = new Stack(); }

July 18, 2007 SWE 619 (c) Aynur Abdurazik 15 Test case with JUnit public void testRepOk(){ boolean result = stack.repOk(); assertEquals(true, result); stack = stack.push(new Integer(1)); result = stack.repOk(); assertEquals(true, result); stack = stack.pop(); result = stack.repOk(); assertEquals(true, result); stack = stack.push(new Integer(1)); stack.top(); result = stack.repOk(); assertEquals(true, result); }

July 18, 2007 SWE 619 (c) Aynur Abdurazik 16 Test case with JUnit public void testToString(){ stack = stack.push(new Integer(1)); stack = stack.push(new Integer(2)); assertEquals("{2, 1}", stack.toString()); public void runAfterEachTest(){ stack = null; } public static junit.framework.Test suite(){ return new JUnit4TestAdapter(StackTest.class); }

July 18, 2007 SWE 619 (c) Aynur Abdurazik 17 How to Run Tests JUnit provides test drivers  Character-based test driver runs from the command line  GUI-based test driver-junit.swingui.TestRunner allows to specify the test class to run, "Run" button examines the chosen class and finds all methods whose names begin with "test." If a test fails, Junit gives the location of the failure and any exceptions that were thrown

July 18, 2007 SWE 619 (c) Aynur Abdurazik 18 JUnit Installation in Eclipse In Eclipse, select Help->Software Updates->Find and Install Choose 'Search For New Features to Install' and select 'Next' Select 'New Remote Site' Enter a name for this server: JUnit Factory Enter (or copy/paste) this url: Install all plug-ins in the 'JUnit Factory' category and restart Eclipse

July 18, 2007 SWE 619 (c) Aynur Abdurazik 19 Generating Tests in Eclipse 1. Select a Java class in Eclipse and click the Generate Tests ( )button 2. When the JUnit Factory view says your test is done, click the link in the Result column to open it 3. Select the test and choose Run->Run As- >Agitar JUnit Test from the main menu

July 18, 2007 SWE 619 (c) Aynur Abdurazik 20 Eclipse JUnit Plugin See tutorial  