src/test/java/net/hostsharing/hsadminng/test/DebuggerDetection.java

@@ -0,0 +1,14 @@
+package net.hostsharing.hsadminng.test;
+
+import lombok.experimental.UtilityClass;
+
+import java.lang.management.ManagementFactory;
+
+@UtilityClass
+public class DebuggerDetection {
+    public static boolean isDebuggerAttached() {
+        // check for typical debug arguments in the JVM input arguments
+        return ManagementFactory.getRuntimeMXBean().getInputArguments().stream()
+                .anyMatch(arg -> arg.contains("-agentlib:jdwp"));
+    }
+}

src/test/java/net/hostsharing/hsadminng/test/IgnoreOnFailure.java

@@ -0,0 +1,20 @@
+package net.hostsharing.hsadminng.test;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Use this annotation on JUnit Jupiter test-methods to convert failure to ignore.
+ *
+ * <p>
+ *     The test-class also has to add the extension {link IgnoreOnFailureExtension}.
+ * </p>
+ */
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+public @interface IgnoreOnFailure {
+    ///  a comment, e.g. about the feature under construction
+    String value() default "";
+}

src/test/java/net/hostsharing/hsadminng/test/IgnoreOnFailureExtension.java

@@ -0,0 +1,52 @@
+package net.hostsharing.hsadminng.test;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+
+import org.junit.jupiter.api.extension.InvocationInterceptor;
+import org.junit.jupiter.api.extension.ReflectiveInvocationContext;
+
+import java.lang.reflect.Method;
+
+import static org.assertj.core.api.Assumptions.assumeThat;
+
+/**
+ * Use this JUnit Jupiter extension to ignore failing tests annotated with annotation {@link IgnoreOnFailure}.
+ *
+ * <p>
+ *     This is useful for outside-in-TDD, if you write a high-level (e.g. Acceptance- or Scenario-Test) before
+ *     you even have an implementation for that new feature.
+ *     As long as no other tests breaks, it's not a real problem merging your new test and incomplete implementation.
+ * </p>
+ * <p>
+ *     Once the test turns green, remove the annotation  {@link IgnoreOnFailure}.
+ * </p>
+ *
+ */
+// BLOG: A JUnit Jupiter extension to ignore failed acceptance tests for outside-in TDD
+public class IgnoreOnFailureExtension implements InvocationInterceptor {
+
+    /// @hidden
+    @Override
+    public void interceptTestMethod(
+            final Invocation<Void> invocation,
+            final ReflectiveInvocationContext<Method> invocationContext,
+            final ExtensionContext extensionContext) throws Throwable {
+
+        try {
+            invocation.proceed();
+        } catch (final Throwable throwable) {
+            if (hasIgnoreOnFailureAnnotation(extensionContext)) {
+                assumeThat(true).as("ignoring failed test with @" + IgnoreOnFailure.class.getSimpleName()).isFalse();
+            } else {
+                throw throwable;
+            }
+        }
+    }
+
+    private static boolean hasIgnoreOnFailureAnnotation(final ExtensionContext context) {
+        final var hasIgnoreOnFailureAnnotation = context.getTestMethod()
+                .map(method -> method.getAnnotation(IgnoreOnFailure.class))
+                .isPresent();
+        return hasIgnoreOnFailureAnnotation;
+    }
+}