Exercise 4

info

This is an in-class exercise. An exercise page like this one will contain a brief description but is intended to be supplemented by discussion during our meeting time. Complete the exercise to the best of your ability in the time given. Feel free to talk with other students as you work, and do not be afraid to ask questions. Aim to complete as much as possible during our meeting, but you need not hand it in.

Learning Objectives#

Objectives

This exercise should help you practice with:

JUnit concepts and mechanics

Quick Question 1: Find the problem#

Assume the following code does not have any syntactical flaws. The goal of the test is to make sure the sort method works as expected. Do you see any issues with this test case?

@Test
public void testSort() {
   names.add ("Laura"); 
   names.add ("Han"); 
   names.add ("Alex"); 
   names.add ("Ashley"); 
   names.sort(); 
   assertTrue ("Sort method", names.getFirst().equals("Alex"));
}

tip

In the testSort method, names is an instance of an object that stores strings and has methods add(), sort(), and getFirst(), which do exactly what you would expect from their names. You can assume that the object names has been properly instantiated and the add() and getFirst() methods have already been tested and work correctly.

Quick Question 2: Test Fxiture#

Assume you were writing a JUnit test class to test the functionalities that ArrayList of Java utilities offers! Also, assume you would wanted to start with an empty ArrayList for each test case. Which of @BeforeEach, @BeforeAll, @AfterEach, and @AfterAll you would make use of? What exactly would go inside each (that you'd use)?

Task 1: Parameterzied Tests machanics#

Recall in task 1 of exercise 3, you were asked to write test cases for countOutsideRange. Implement the test cases you developed there as a single paramerized test.

tip

Try to look up and find out how you can write parameterized tests where an input to the function is an array. Also, how would you go about tailoring the expected value for each test case?

Task 2: Tag and Filter#

Do a git pull on the course public repo that contains test cases in a file named TriangleTest.java for Triangle.triangle included in jhu-triangle-0.1.0.jar that we worked on in exercise 2:

Tag each test case in TriangleTest.java as either EP i.e., equivalnce partitioning or BA i.e., boundary analysis or both. Then (by making adjustments in build.gradle) run only EP tests. Then, run only BA tests.
EXTRA PRACTICE: rewrite all test cases with identical tag(s) as a single parameterized test case.

tip

If needed, refer to exercise 2 on how to include a jar file in your gradle project!