Testing void methods

[Laxmi]

How to write JUNIT test for testing void methods?

[Kishan]

Good coding practice is every line of application code we are going to write should be testable. If any code is not testable means definitely code can be improved.

Example for class with void method: removeDuplicates method will remove duplicate values from give list of values.

Code: Select all

public class DataUtils {
   public static void removeDuplicates(List<String> list) {
        //here you can write a logic to remove duplicate values from given list.
   }
}

Test Class for above removeDuplicates method:

Code: Select all

public class DataUtilsTest {
   @Test
    public void testRemoveDuplicates() {
        List<String> list = new ArrayList<String>();
        list.add("John");
        list.add("Dave");
        list.add("John");
        DataUtilis.removeDuplicates(list);
        Assert.assertEquals(2, list.size());
        Assert.assertEquals(1, Collections.frequency(list, "John"));
    }
}