Detect Failure or Error of Junit Test in @After method

Question

Is there a way in JUnit to detect within an @After annotated method if there was a test failure or error in the test case?

One ugly solution would b

Answer 1

I extend dsaff's answer to solve the problem that a TestRule can not execute some code snipped between the execution of the test-method and the after-method. So with a simple MethodRule one can not use this rule to provide a success flag that is use in the @After annotated methods.

My idea is a hack! Anyway, it is to use a TestRule (extends TestWatcher). A TestRule will get knowledge about failed or success of a test. My TestRule will then scan the class for all Methods annotated with my new AfterHack annotations and invoke that methods with a success flag.

---

AfterHack annotation

import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;    
import java.lang.annotation.Retention;
import java.lang.annotation.Target;

@Retention(RUNTIME)
@Target(METHOD)
public @interface AfterHack {}

AfterHackRule

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

import org.junit.rules.TestWatcher;
import org.junit.runner.Description;

public class AfterHackRule extends TestWatcher {

    private Object testClassInstance;
    public AfterHackRule(final Object testClassInstance) {
        this.testClassInstance = testClassInstance;
    }

    protected void succeeded(Description description) {
        invokeAfterHackMethods(true);
    }

    protected void failed(Throwable e, Description description) {
        invokeAfterHackMethods(false);
    }

    public void invokeAfterHackMethods(boolean successFlag) {
        for (Method afterHackMethod :
                    this.getAfterHackMethods(this.testClassInstance.getClass())) {
            try {
                afterHackMethod.invoke(this.testClassInstance, successFlag);
            } catch (IllegalAccessException | IllegalArgumentException
                     | InvocationTargetException e) {
                throw new RuntimeException("error while invoking afterHackMethod " 
                          + afterHackMethod);
            }
        }
    }

    private List getAfterHackMethods(Class testClass) {
        List results = new ArrayList<>();            
        for (Method method : testClass.getMethods()) {
            if (method.isAnnotationPresent(AfterHack.class)) {
                results.add(method);
            }
        }
        return results;
    }
}

---

Usage:

public class DemoTest {

    @Rule
    public AfterHackRule afterHackRule = new AfterHackRule(this);

    @AfterHack
    public void after(boolean success) { 
        System.out.println("afterHack:" + success);
    }

    @Test
    public void demofails() {
        Assert.fail();
    }

    @Test
    public void demoSucceeds() {}
}

---

BTW:

• 1) Hopefully there is a better solution in Junit5
• 2) The better way is to use the TestWatcher Rule instead of the @Before and @After Method at all (that is the way I read dsaff's answer)

@see