3.2.11. Extensions for JUnit 5¶

// 1. Specify the baseUri of BasicHttpRequestTest
@BasicHttpRequestTest(baseUri = "/test/")
class YourTestClass {
    // 2. The method of injecting BasicHttpRequestTestTemplate is the same as the others.
    BasicHttpRequestTestTemplate support;

    @Test
    void test() {
        support.execute();
    }
}

public class CustomTestSupport extends TestSupport {
    // Implement the constructor to pass the Class instance of the test class to TestSupport.
    public CustomTestSupport(Class<?> testClass) {
        super(testClass);
    }

    // Implement your own extension methods
}

public class CustomTestSupportExtension extends TestSupportExtension {

    // Override createSupport() and implement it to return an instance of your own extension class
    @Override
    protected TestEventDispatcher createSupport(Object testInstance, ExtensionContext context) {
        return new CustomTestSupport(testInstance.getClass());
    }
}

..
import org.junit.jupiter.api.extension.ExtendWith;

// 1. ExtendWith to apply the Extension for your own extension to the test class
@ExtendWith(CustomTestSupportExtension.class)
class YourTest {
    // 2. Declare an instance field of your own extension class.
    CustomTestSupport support;

    @Test
    void test() {
        // 3. Use your own extension classes in your tests
        support.customMethod();
    }
}

public class CustomHttpRequestTestSupport extends BasicHttpRequestTestTemplate {
    private final String baseUri;

    // Implement baseUri so that it can be passed from outside.
    public CustomHttpRequestTestSupport(Class<?> testClass, String baseUri) {
        super(testClass);
        this.baseUri = baseUri;
    }

    @Override
    protected String getBaseUri() {
        return baseUri;
    }
}

import org.junit.jupiter.api.extension.ExtendWith;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
// Specify the Extension for your own extension to be created later.
@ExtendWith(CustomHttpRequestTestExtension.class)
public @interface CustomHttpRequestTest {
    // Declare the baseUri
    String baseUri();
}

public class CustomHttpRequestTestExtension extends BasicHttpRequestTestExtension {

    @Override
    protected TestEventDispatcher createSupport(Object testInstance, ExtensionContext context) {
        // Obtaining annotation information from the test class
        CustomHttpRequestTest annotation = findAnnotation(testInstance, CustomHttpRequestTest.class);
        // Pass the baseUri information to the constructor of your own extension class
        return new CustomHttpRequestTestSupport(testInstance.getClass(), annotation.baseUri());
    }
}

// Set your own composed annotation to the test class (also set baseUri)
@CustomHttpRequestTest(baseUri = "/custom/")
class YourTest {
    // Declare the fields of your own extension class
    CustomHttpRequestTestSupport support;

    @Test
    void test() {
        // Use your own extension class in Tests
        support.customMethod();
    }
}

@Override
public void beforeAll(ExtensionContext context) {
    // Always execute the parent's method first.
    super.beforeAll(context);

    // Implement your own pre-processing
    ...
}

import org.junit.Rule;
import org.junit.rules.Timeout;
import java.util.concurrent.TimeUnit;

public class CustomTestSupport extends TestSupport {
    // Using the TestRule of JUnit 4
    @Rule
    public Timeout timeout = new Timeout(1000, TimeUnit.MILLISECONDS);

    public CustomTestSupport(Class<?> testClass) {
        super(testClass);
    }
}

public class CustomTestSupportExtension extends TestSupportExtension {

    @Override
    protected TestEventDispatcher createSupport(Object testInstance, ExtensionContext context) {
        return new CustomTestSupport(testInstance.getClass());
    }

    // 1. Override the resolveTestRules method
    @Override
    protected List<TestRule> resolveTestRules() {
        // 2. Generate a list based on the result of resolveTestRules() of the parent class
        List<TestRule> rules = new ArrayList<>(super.resolveTestRules());
        // 3. Add the TestRule defined in your own extension class to the list
        rules.add(((CustomTestSupport) support).timeout);
        // 4. Return the generated list
        return rules;
    }
}