Junit before class ( non static )

Question

Are there any best practices to get Junit execute a function once in a test file , and it should also not be static.

like @BeforeClass on non static fun

Answer 1

To use an empty constructor is the easiest solution. You can still override the constructor in the extended class.

But it's not optimal with all the inheritance. That's why JUnit 4 uses annotations instead.

Another option is to create a helper method in a factory/util class and let that method do the work.

If you're using Spring, you should consider using the @TestExecutionListeners annotation. Something like this test:

@RunWith(SpringJUnit4ClassRunner.class)
@TestExecutionListeners({CustomTestExecutionListener.class, 
     DependencyInjectionTestExecutionListener.class})
@ContextConfiguration("test-config.xml")
public class DemoTest {

Spring's AbstractTestExecutionListener contains for example this empty method that you can override:

public void beforeTestClass(TestContext testContext) throws Exception {
    /* no-op */
}

NOTE: DO NOT overlook/miss DependencyInjectionTestExecutionListener while adding custom TestExecutionListeners. If you do, all the autowires will be null.