CODEWITHSUNDEEP
javajunit4
Ian Hamilton
Ian Hamilton

Reputation: 43

How to unit test a class with multiple boolean fields

Sorry if this is a dumb question. I'd like to unit test the following class (there's more to the class but I stripped it down to illustrate my question).

The class consists of multiple boolean fields that get assigned in the constructor.

When I'm unit testing how can I test the parameters are assigned to the correct class field e.g. ans1 -> mIsOption1Ans ?

For example if I assert that all the class fields are "true" this will not identify if another developer has accidentally swapped the assignment in the constructor and assigned a parameter to the wrong class field. I'd like to test that "ans1" always gets assigned to "mIsOption1Ans", etc, etc

public class MultipleChoiceQuizAnswer {
   private Boolean mIsOption1Ans,mIsOption2Ans,mIsOption3Ans,mIsOption4Ans;

   public QuizAnswer (Boolean ans1,Boolean ans2, Boolean ans3,Boolean ans4) {
         mIsOption1Ans = ans1;
         mIsOption2Ans = ans2;
         mIsOption3Ans = ans3;
         mIsOption4Ans = ans4;
    }
}

Upvotes: 4

Views: 1681

Answers (2)

Stefan Birkner
Stefan Birkner

Reputation: 24520

Your fields are an internal state of the objects. You should only test the class' behavior to the outside world. The fields' values cause some external behavior of QuizAnswer, which should be tested. E.g. if you have a method that checks whether an option is the answer:

@Test
public void first_option_is_the_answer_when_ans1_flag_is_true() {
    QuizAnswer answer = new QuizAnswer(true, false, false, false);
    boolean firstOptionIsAnswer = answer.isNthOptionTheAnswer(1);
    assertTrue(firstOptionIsAnswer);
}

You may have a look at JUnit's Parameterized runner, because you may want to write data driven tests.

Upvotes: 3

FilipRistic
FilipRistic

Reputation: 2821

This is really obvious thing but if you really want to test it you can test for each situation where 1 boolean is true and rest are false.

So for example: 

QuizAnswer firstTrue = QuizAnswer(true, false, false, false);
assertTrue(firstTrue.isFirstAnswer());
// Then for next:
QuizAnswer secondTrue = QuizAnswer(false, true, false, false);
assertTrue(secondTrue.isSecondAnswer());
// Etc. You could also check if all other answers are false

Upvotes: 3

Related Questions