JUnit on Eclipse. Chien-Tsun Chen Sep. 23, 2003

Transcription

1 JUnit on Eclipse Chien-Tsun Chen Sep. 23, 2003

2 Outline Introduction to JUnit Using JUnit on Eclipse, By Example Resources Q&A

3 Introduction to JUnit

4 What is JUnit? JUnit is an open source Java unit testing framework used to write and run repeatable tests. It is an instance of the xunit architecture for unit testing frameworks. Unit testing is white box testing, that is, testing performed by programmers.

5 JUnit Overview 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

6 JUnit Architecture

7 A Simplified Workflow of Applying JUnit Test Cases Test Methods Test Suites Writing Production Code Writing Test Code *.java Test Runner Running Test Code Any Errors? No Yes Fixing the problems by modifying production or test code

8 Example: A Dictionary Class Only supports three methods: valuefor (String k)- If Key k exists, return the corresponding stored Object o, else return null. put (String k, Object o)- Store an Object o and bind it to the Key k. put() should not accept duplicate key. remove (String k)- Remove an Object o with Key k and return the Object o. Return null if key does not exist. Using Java build-in Hashtable Class to store internal data.

9 Dictionary Example, Part I Give JUnit a Try

10 Steps of the example, part I Step : Create a new project in Eclipse. Step 2: Create a new Java class (Dictionary). Step 3: Create a test case (DictionaryTest). Step 4: Write fixture and a test method. Step 5: Run JUnit. Step 6: Find and fix the bugs, and run JUnit again.

11 Step : Create a new project in Eclipse (/3) 2 3

12 Step : Enter project name (2/3) 2

13 Step : Project s default settings (3/3)

14 Step 2: Create a new Java Class (/3)

15 Step 2: Enter Package and Class Name (2/3) 2 3

16 Step 2: Write class code (3/3) 2 3 4

17 Step 3: Create a test case (/5) 2

18 Step 3: Create a test case (2/5) 2 3

19 Step 3: Create a test case (3./5) If you see this error message

20 Step 3: Create a test case (3.2/5) 2 3 3

21 Step 3: Create a test case (4/5) 2

22 Step 3: Create a test case (5/5) 2

23 Step 4: Write fixture and a test method 2 3 Write testvaluefor() only. (we will write the other tow test methods later.)

24 Step 5: Run JUnit 2 3

25 Step 6: Find bugs (/2)

26 Step 6: Fix the bug and run again (2/2) 2 3

27 Dictionary Example, Part II Complete TestPut() and testremove()

28 Steps of the example, part II Step : Write testput(). Step 2: Write an error version of testremove(). Step 3: Fix the error of testremove().

29 Step : Write testput() 3 2

30 Step 2: testremore() with error? 3 2

31 Step 3: testremore() without error 3 2

32 Dictionary Example, Part III We Need More Tests

33 Do we need more tests? 2 Class Dictionary 3 Can we do this? (duplicate key, A ) 4 What to test?

34 Animal overwrites Apple since their both have the same key A

35 No error. Animal really overwrite Apple

36 What s next? We don t want duplicate key, so we revise put() New problem: How to test exception?

37 2 It works. We can find duplicate key, but cannot pass the test 3

38 2 Write a new test method, and run again. Still has error. 3

39 Throw exception 2 Catch the exception thrown by put() Fix the error.

40 Using Test Suite

41 Steps of the example Step: Create AllTests suite that includes three test cases. Step2: Create DictionaryOnlyTest suite that includes only DictionaryTest test case. Step3:Create a JUnit configuration file to run the first test suite. Step 4: Create another JUnit configuration file to run the second test suite. Step 5: We can switch between these two configuration files.

42 Step : Select File->New->Other (/4)

43 Step : Select TestSuite (2/4) 2 3

44 Step : Test suite s data (3/4) 2 3

45 Step : Class AllTests is created automatically (4/4) 2 3

46 Step 2: Create another test suite (/2) 2 3

47 Step 2: Class DictionaryOnlyTest is created automatically (2/2)

48 Project Overview After Finishing Step and Step 2

49 Step 3: Prepare to run the test suite (/6)

50 Step 3: New a JUnit Configuration (2/6)

51 Step 3: JUnit Configuration Property (3/6) 2 3

52 Step 3: Select AllTests (4/6) 2 3

53 Step 3: Run this configuration (5/6)

54 Step 3: Results-We have assertions (6/6)

55 Step 4: New another JUnit Configuration and Run it (/2) 2 3

56 Step 4: Results-We have only 5 assertions (2/2)

57 Step 5: Select a different configuration file 2

58 Resources JUnit.org, Eclipse.org,

59 Q&A

60 Add JUnit Reference to Eclipse Build Path

61 (/7) 2

62 (2/7) 2 3 4

63 (3/7) 2 3 4

64 (4/7) 2

65 (5/7) C:/eclipse/plugins/org.eclipse.jdt.source_2../src/org.junit_3.8./junitsrc.zip 2 3 4

66 (6/7) 2 3 4

67 (7/7)