How to attach a DataPoint with a Theory?

Question

@DataPoints public static final Integer[] input1={1,2};
@Theory
@Test
public void test1(int input1){

}

@DataPoints public static final Integer[] input2={3,4};
@Theory
         


        

Answer 1

With JUnit 4.12 (not sure when it was introduced) it is possible to name the DataPoints and assign them to parameters (i learned it from http://farenda.com/junit/junit-theories-with-datapoints/):

    @RunWith(Theories.class)
    public class TheoriesAndDataPointsTest {
        @DataPoints("a values")
        public static int[] aValues() {
            return new int[]{1, 2};
        }

        @DataPoints("b values")
        public static int[] bValues() {
            return new int[]{3, 4};
        }

        @Theory
        public void theoryForA(@FromDataPoints("a values") int a) {
            System.out.printf("TheoryForA called with a = %d\n", a);
        }

        @Theory
        public void theoryForB(@FromDataPoints("b values") int a) {
            System.out.printf("TheoryForB called with b = %d\n", a);
        }
    }

Output:

TheoryForA called with a = 1
TheoryForA called with a = 2
TheoryForB called with b = 3
TheoryForB called with b = 4