JUnit two variables iterating respective value sets, create test functions

Question

Checking function takes two arguments, I want to have a testcase for each element of the cartesian product of the respective domains, but without manually writing all the test cases like in

void check(Integer a, Integer b) { ... }

@Test
public void test_1_2() { check(1, 2); }

...

In python I would go with

class Tests(unittest.TestCase):
    def check(self, i, j):
        self.assertNotEquals(0, i-j)



for i in xrange(1, 4):
    for j in xrange(2, 6):
        def ch(i, j):
            return lambda self: self.check(i, j)
        setattr(Tests, "test_%r_%r" % (i, j), ch(i, j))

How could I do this with Java and JUnit?

dfa · Accepted Answer · 2009-07-27 09:54:16Z

5

with theories you can write something like:

@RunWith(Theories.class)
public class MyTheoryOnUniverseTest {

    @DataPoint public static int a1 = 1;
    @DataPoint public static int a2 = 2;
    @DataPoint public static int a3 = 3;
    @DataPoint public static int a4 = 4;

    @DataPoint public static int b2 = 2;
    @DataPoint public static int b3 = 3;
    @DataPoint public static int b4 = 4;
    @DataPoint public static int b5 = 5;
    @DataPoint public static int b6 = 6;

    @Theory
    public void checkWith(int a, int b) {
        System.out.format("%d, %d\n", a, b);
    }
}

(tested with JUnit 4.5)

EDIT

Theories also produces nice error messages:

Testcase: checkWith(MyTheoryOnUniverseTest):        Caused an ERROR
checkWith(a1, b2) // <--- test failed, like your test_1_2

so you don't need to name your test in order to easly identify failures.

EDIT2

alternatively you can use DataPoints annotation:

@DataPoints public static int as[] = { 1, 2, 3, 4} ;
@DataPoints public static int bs[] = { 2, 3, 4, 5, 6};

@Theory
public void checkWith(int a, int b) {
    System.out.format("%d, %d\n", a, b);
}

edited Jul 27, 2009 at 9:54

answered Jul 27, 2009 at 9:34

dfa

117k32 gold badges193 silver badges229 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

SigmaX Over a year ago

I agree that Theories is the best tool when you want all combinations—but this answer is buggy. Theories doesn't look at your variable names, so it can't tell the difference between the two sets. What you get is the Cartesian product of [ 1, 2, 3, 4, 2, 3, 4, 5, 6 ] with itself. This is true for both the \@DataPoint and \@DataPoints methods.

Brian Agnew · Accepted Answer · 2009-07-27 09:13:55Z

2

I would look at JUnit 4's parameterised tests, and generate the array of test data dynamically.

answered Jul 27, 2009 at 9:13

Brian Agnew

273k38 gold badges342 silver badges443 bronze badges

1 Comment

Stroboskop Over a year ago

Now for the question that is always asked with JUnit 4 parametrised tests - how do you set the test case's names?

Community · Accepted Answer · 2017-05-23 12:30:43Z

1

I think your looking for Parameterized Tests in JUnit 4.

JUnit test with dynamic number of tests

edited May 23, 2017 at 12:30

CommunityBot

11 silver badge

answered Jul 27, 2009 at 9:08

bruno conde

48.3k15 gold badges103 silver badges118 bronze badges

Collectives™ on Stack Overflow

JUnit two variables iterating respective value sets, create test functions

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related