Hey Invaders! 👽

#100DaysOfCode day 10, I continued working on my JUnit course and finished section 6: Advanced JUnit 5. Today, I learned and practiced using method orders and test instances. Here's a summary of what I covered:

• Method Orders:

  • Control the order in which test methods are executed.

  • @TestMethodOrder(MethodOrderer.Random.class): Executes test methods in a random order.

  • @TestMethodOrder(MethodOrderer.MethodName.class): Executes test methods in lexicographic(a generalization of the alphabetical order of the dictionaries to sequences of ordered symbols or, more generally, of elements of a totally ordered set.) order by method name.

  • @TestMethodOrder(MethodOrderer.OrderAnnotation.class): Executes test methods based on the @Order annotation.

• Test Instances:

  • Manage the lifecycle of test instances.

  • @TestInstance(TestInstance.Lifecycle.PER_METHOD): A new test instance is created for each test method (default behavior, you don’t have to add this annotation but this is what Junit uses).

  • @TestInstance(TestInstance.Lifecycle.PER_CLASS): A single test instance is used for all test methods within the test class.

Here's some code snippet demonstrating these concepts:

• @TestMethodOrder(MethodOrderer.Random.class): these can be executed as DBAC when the tests are complied for example

@TestMethodOrder(MethodOrderer.Random.class)
public class MethodOrderedRandomlyTest {

    @Test
    void TestA(){
        System.out.println("Running Test A");
    }

    @Test
    void TestB(){
        System.out.println("Running Test B");
    }

    @Test
    void TestC(){
        System.out.println("Running Test C");
    }

    @Test
    void TestD(){
        System.out.println("Running Test D");
    }

• @TestMethodOrder(MethodOrderer.MethodName.class): these will run as ABCD no matter the order they are put in

@TestMethodOrder(MethodOrderer.MethodName.class)
public class MethodOrderedRandomlyTest {


    @Test
    void TestD(){
        System.out.println("Running Test D");
    }

    @Test
    void TestA(){
        System.out.println("Running Test A");
    }

    @Test
    void TestC(){
        System.out.println("Running Test C");
    }

   @Test
    void TestB(){
        System.out.println("Running Test B");
    }

• @TestMethodOrder(MethodOrderer.OrderAnnotation.class): these will be DACB because of the Order annotation used

@TestMethodOrder(MethodOrderer.OrderAnnotation.class)
public class MethodOrderedRandomlyTest {

    @Order(1)
    @Test
    void TestD(){
        System.out.println("Running Test D");
    }

    @Order(2)
    @Test
    void TestA(){
        System.out.println("Running Test A");
    }

    @Order(3)
    @Test
    void TestC(){
        System.out.println("Running Test C");
    }

    @Order(4)
    @Test
    void TestB(){
        System.out.println("Running Test B");
    }

Here’s a little graphic I made to help you visualize how the Test Instance annotations work in Junit!

• @TestInstance(TestInstance.Lifecycle.PER_CLASS): for an example of how to use this annotation please visit my github repo avrubio/JUnitUdemyCourse

This course continues to be enlightening and is helping me become proficient in writing efficient and well-structured tests.

Happy coding! 💪