How to use getAnnotation method of org.junit.experimental.theories.ParameterSignature class

Epsilon is the value that the 2 numbers can be off by. So it will assert to true as long as Math.abs(expected - actual) <= epsilon

Rules are used to add additional functionality which applies to all tests within a test class, but in a more generic way.

For instance, ExternalResource executes code before and after a test method, without having to use @Before and @After. Using an ExternalResource rather than @Before and @After gives opportunities for better code reuse; the same rule can be used from two different test classes.

The design was based upon: Interceptors in JUnit

For more information see JUnit wiki : Rules.

1. The test runner will effectively make a single Suite of all of your tests and run them - so that only one classloader is involved.
2. Yes that means that static data will be shared between tests, which can occasionally be handy, but will force you to cut down on the static coupling between clauses, which is a good thing.
3. There isn't generally any explicit GC, but you can do your own.

Generally running all your tests in one VM is a good thing. It forces you to look at static coupling and is a lot quicker. Crucially, it's also the way that your IDE will be running them, and that really is the way that tests should be run - as close as possible to as often as you compile.

For me there are two points:

1. Refactorings (IntelliJ is great in the refactorings it provides)

2. Plugin stability, I've always found that when I have a stable install of Eclipse, I get a new plugin and everything comes down in flames and I have to reinstall everything.

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.

Not sure this will solve your problem but GlassFish Embedded provides a Java EE 6 implementation. Add this to your pom.xml:

<project>
  ...
  <repositories>
    <repository>
      <id>glassfish-extras-repository</id>
      <url>http://download.java.net/maven/glassfish/org/glassfish/extras</url>
    </repository>
  </repositories>
  ...
  <dependencies>
    <dependency>
      <groupId>org.glassfish.extras</groupId>
      <artifactId>glassfish-embedded-all</artifactId>
      <version>3.0.1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>javax</groupId>
      <artifactId>javaee-api</artifactId>
      <version>6.0</version>
      <scope>provided</scope>
    </dependency>
    ...
  </dependencies>
  ...
</project>

It's important to declare the glassfish-embedded-all artifact before the javaee-api.

Using the Maven Surefire plugin and JUnit 5 together requires some tweaking ...

From the docs:

The JUnit team has developed a very basic provider for Maven Surefire that lets you run JUnit 4 and JUnit Jupiter tests via mvn test. The pom.xml file in the junit5-maven-consumer project demonstrates how to use it and can serve as a starting point.

Due to a memory leak in Surefire 2.20, the junit-platform-surefire-provider currently only works with Surefire 2.19.1.

...
<build>
    <plugins>
        ...
        <plugin>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>2.19</version>
            <dependencies>
                <dependency>
                    <groupId>org.junit.platform</groupId>
                    <artifactId>junit-platform-surefire-provider</artifactId>
                    <version>1.0.0</version>
                </dependency>
            </dependencies>
        </plugin>
    </plugins>
</build>
...

I have found Embedded MongoDB library which looks quite promising and does what you have asked for.

Currently supports MongoDB versions: 1.6.5 to 3.1.6, provided the binaries are still available from the configured mirror.

Here is short example of use, which I have just tried and it works perfectly:

public class EmbeddedMongoTest {
    private static final String DATABASE_NAME = "embedded";

    private MongodExecutable mongodExe;
    private MongodProcess mongod;
    private Mongo mongo;

    @Before
    public void beforeEach() throws Exception {
        MongoDBRuntime runtime = MongoDBRuntime.getDefaultInstance();
        mongodExe = runtime.prepare(new MongodConfig(Version.V2_3_0, 12345, Network.localhostIsIPv6()));
        mongod = mongodExe.start();
        mongo = new Mongo("localhost", 12345);
    }

    @After
    public void afterEach() throws Exception {
        if (this.mongod != null) {
            this.mongod.stop();
            this.mongodExe.stop();
        }
    }

    @Test
    public void shouldCreateNewObjectInEmbeddedMongoDb() {
        // given
        DB db = mongo.getDB(DATABASE_NAME);
        DBCollection col = db.createCollection("testCollection", new BasicDBObject());

        // when
        col.save(new BasicDBObject("testDoc", new Date()));

        // then
        assertThat(col.getCount(), Matchers.is(1L));
    }
}

Ideally, you should "favor composition over inheritance".

If you don't have this option you could use doNothing which basically tells Mockito to do nothing when a method in a mock/spy object is called. This was also discussed here

Following code example should help

@Test
public void tst() {
    ChildClass ch = Mockito.spy(new ChildClass());
    Mockito.doNothing().when((SuperClass)ch).run();
    ch.childRunner();

}

class SuperClass{
    public void run(){
        System.out.println("I am running in Super class");
    }
}

class ChildClass extends SuperClass{
    public void childRunner(){
        System.out.println("Step 1");
        run();
        System.out.println("Last Step");
    }
}

output:

Step 1
Last Step

In case you use super.run(); this won't work