Thanks so much !

You don’t need them run in any order and you must not infact. Because test case must be independent. It means, it must run successfully without dependent (data, condition etc.) of any other test case(s). This is an important feature of test cases.

So, you have to setup your test case’s running condition before it runs, you check or test something (using asserts) and you leave your environment in its state before the setting up process. The setUp() and tearDown() methods (naming convention before the JUnit 4.x) is generally used for this purpose. Because they run before and after each test case. They are annotated as @Before and @After in JUnit 4.X as we mentioned.

In your example, you can create a user in a method annotated with @Before and you delete that user in in another method annotated with @After. Therefore, you guarantee that you have a user that you exactly know in your system to test your other methods. It can be something like that:

@Before
public void initializeSystem() {
// user: id, name, surname
this.user = userDAO.createUser(1, “Foo”, “Bar”);
}

@Test
public void getUserById() {
User newUser = userDAO.findUserById(1);
assertEquals(this.user.getName(), newUser.getName());
assertEquals(this.user.getSurname(), newUser.getSurname());
}

@After
public void cleanSystemState() {
userDAO.deleteUser(this.user);
}

For the above example, you have to guarantee that createUser() and deleteUser() methods are running correctly of course.

I hope, it gives the general approach of independent unit testing. Creating such an environment is not easy I know. However, when we try to test our system as isolated and independent as possible, we not only testing our system, we are improving our overall architecture without noticing it. So, we have well-defined, fully tested, ready to use components and interfaces. I think, this is what we try to achieve.

I have a question that do the test cases run in order or not?

Ex: I have test class includes 3 cases (testMethod1, testMethod2, testMethod3)

When running, I see sometimes they run in order

testMethod1
testMethod2
testMethod3

but sometimes is not (2,1,3 or 3,2,1 …). Since I’m using a data sharing between them so that I must assure they will be run in order. My real case is :

testCreateUser() –> always make sure this case will run firstly

These case will be fail or error if testCreateUser() did not run before:

testGetUserByID()
testEditUser()
…

Anyone can help me to show how to make them run in order always? I’m using JUnit4.x

Thanks a lot.