List of Classes and Methods of org.junit.experimental.theories.suppliers package of junit Framework

Take a look at junit categories.

You'd tag your tests with specific category annotations

public interface FastTests { /* category marker */ }
public interface SlowTests { /* category marker */ }

@Category(SlowTests.class)
public class A {
    @Test public void a() {}
}

then form a suite like

@RunWith(Categories.class)
@IncludeCategory({FastTests.class})
@SuiteClasses({A.class, B.class})
public static class FastTestSuite {
     //
}

And then run it with

mvn -Dtest=FastTestSuite test

Note also that if you don't want to manually specify your unit test case classes in the suite class, you can also use the help of ClasspathSuite and then just limit based on categories.

Use @BeforeEach instead of @Before and @AfterEach instead of @After.

JUnit 4.8 supports grouping:

public interface SlowTests {}
public interface IntegrationTests extends SlowTests {}
public interface PerformanceTests extends SlowTests {}

And then...

public class AccountTest {

    @Test
    @Category(IntegrationTests.class)
    public void thisTestWillTakeSomeTime() {
        ...
    }

    @Test
    @Category(IntegrationTests.class)
    public void thisTestWillTakeEvenLonger() {
        ...
    }

    @Test
    public void thisOneIsRealFast() {
        ...
    }
}

And lastly,

@RunWith(Categories.class)
@ExcludeCategory(SlowTests.class)
@SuiteClasses( { AccountTest.class, ClientTest.class })
public class UnitTestSuite {}

Taken from here: https://community.oracle.com/blogs/johnsmart/2010/04/25/grouping-tests-using-junit-categories-0

Also, Arquillian itself supports grouping: https://github.com/weld/core/blob/master/tests-arquillian/src/test/java/org/jboss/weld/tests/Categories.java

Using the Hamcrest CoreMatcher (included in JUnit 4.4 and later) and assertThat():

assertThat(myString, anyOf(is("value1"), is("value2")));

assertTrue will fail if the second parameter evaluates to false (in other words, it ensures that the value is true). assertFalse does the opposite.

assertTrue("This will succeed.", true);
assertTrue("This will fail!", false);

assertFalse("This will succeed.", false);
assertFalse("This will fail!", true);

As with many other things, the best way to become familiar with these methods is to just experiment :-).

Can you be more precise? Do you need to understand what are @Before and @Test annotation?

@Test annotation is an annotation (since JUnit 4) that indicates the attached method is an unit test. That allows you to use any method name to have a test. For example:

@Test
public void doSomeTestOnAMethod() {
  // Your test goes here.
  ...
}

The @Before annotation indicates that the attached method will be run before any test in the class. It is mainly used to setup some objects needed by your tests:

(edited to add imports) :

import static org.junit.Assert.*; // Allows you to use directly assert methods, such as assertTrue(...), assertNull(...)

import org.junit.Test; // for @Test
import org.junit.Before; // for @Before

public class MyTest {

    private AnyObject anyObject;

    @Before
    public void initObjects() {
        anyObject = new AnyObject();
    }

    @Test
    public void aTestUsingAnyObject() {
        // Here, anyObject is not null...
        assertNotNull(anyObject);
        ...
    }

}

Just move out the tests that don't need the setup code into a separate test class. If you have some other code common to the tests that would be helpful to keep, move that out into a helper class.

Dumbster is a fake SMTP server designed for testing against. It's written in Java.

Ok, you've declared junit dependency for test classes only (those that are in src/test/java but you're trying to use it in main classes (those that are in src/main/java).

Either do not use it in main classes, or remove <scope>test</scope>.