Assumptions and Conditional Test Execution with JUnit 4 and 5

AssumeConnection.java

@Retention(RetentionPolicy.RUNTIME)
@ExtendWith(AssumeConnectionCondition.class)
public @interface AssumeConnection {

  String uri();

}

AssumeConnectionCondition.java

public class AssumeConnectionCondition implements ExecutionCondition {

  @Override
  public ConditionEvaluationResult evaluateExecutionCondition(ExtensionContext context) {
    Optional<AssumeConnection> annotation = findAnnotation(context.getElement(), AssumeConnection.class);
    
    if (annotation.isPresent()) {
      String uri = annotation.get().uri();
      ConnectionChecker checker = new ConnectionChecker(uri);
      if (!checker.connect()) {
        return ConditionEvaluationResult.disabled(String.format("Could not connect to '%s'. Skipping test!", uri));
      } else {
        return ConditionEvaluationResult.enabled(String.format("Successfully connected to '%s'. Continuing test!", uri));
      }
    }
    
    return ConditionEvaluationResult.enabled("No AssumeConnection annotation found. Continuing test.");
  }

}

AssumingConnection.java

public class AssumingConnection implements TestRule {

  private ConnectionChecker checker;

  public AssumingConnection(ConnectionChecker checker) {
    this.checker = checker;
  }

  @Override
  public Statement apply(Statement base, Description description) {
    return new Statement() {
      @Override
      public void evaluate() throws Throwable {
        if (!checker.connect()) {
          throw new AssumptionViolatedException("Skipping Test!"); 
        } else {
          base.evaluate();
        }
      }
    };
  }

}

ConnectionChecker.java

public class ConnectionChecker {
  private String uri;
  
  public ConnectionChecker(String uri){
    this.uri = uri;
  }

  public boolean connect() {
    ... // try to connect to the uri 
  }
}

ConnectionCheckingJunit4Test.java

public class ConnectionCheckingJunit4Test {

  @ClassRule
  public static AssumingConnection assumingConnection = 
      new AssumingConnection(new ConnectionChecker("http://my.integration.system"));

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

}

ConnectionCheckingJunit5Test.java

@AssumeConnection(uri = "http://my.integration.system")
public class ConnectionCheckingJunit5Test {

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

}

ConnectionCheckingTest.java

public class ConnectionCheckingTest {

  private ConnectionChecker connectionChecker = 
      new ConnectionChecker("http://my.integration.system");

  @Test
  public void testOnlyWhenConnected() {
    assumeTrue(connectionChecker.connect());
    ... // your test steps
  }

}