Polish TestDescriptor implementations

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/ClassTestDescriptor.java

@@ -17,7 +17,6 @@
 import static org.junit.gen5.engine.junit5.descriptor.LifecycleMethodUtils.findBeforeEachMethods;
 import static org.junit.gen5.engine.junit5.execution.MethodInvocationContextFactory.methodInvocationContext;
 
-import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
 import java.util.List;
 import java.util.Set;
@@ -245,9 +244,8 @@ private void invokeMethodInTestExtensionContext(Method method, TestExtensionCont
 	}
 
 	@Override
-	protected String generateDefaultDisplayName(AnnotatedElement element) {
-		Class<?> testClass = (Class<?>) element;
-		String name = testClass.getName();
+	protected String generateDefaultDisplayName() {
+		String name = this.testClass.getName();
 		int index = name.lastIndexOf('.');
 		return name.substring(index + 1);
 	}

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/DynamicTestTestDescriptor.java

@@ -10,22 +10,18 @@
 
 package org.junit.gen5.engine.junit5.descriptor;
 
-import static org.junit.gen5.commons.meta.API.Usage.Internal;
-
 import org.junit.gen5.api.DynamicTest;
-import org.junit.gen5.commons.meta.API;
 import org.junit.gen5.engine.TestDescriptor;
 import org.junit.gen5.engine.TestSource;
 import org.junit.gen5.engine.UniqueId;
 import org.junit.gen5.engine.support.descriptor.AbstractTestDescriptor;
 
 /**
- * {@link TestDescriptor} for dynamic tests.
+ * {@link TestDescriptor} for a {@link DynamicTest}.
  *
  * @since 5.0
  */
-@API(Internal)
-public class DynamicTestTestDescriptor extends AbstractTestDescriptor {
+class DynamicTestTestDescriptor extends AbstractTestDescriptor {
 
 	private final DynamicTest dynamicTest;
 

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/JUnit5TestDescriptor.java

@@ -60,11 +60,11 @@ protected String determineDisplayName(AnnotatedElement element) {
 		return findAnnotation(element, DisplayName.class)
 				.map(DisplayName::value)
 				.filter(StringUtils::isNotBlank)
-				.orElse(generateDefaultDisplayName(element));
+				.orElse(generateDefaultDisplayName());
 		// @formatter:on
 	}
 
-	protected abstract String generateDefaultDisplayName(AnnotatedElement element);
+	protected abstract String generateDefaultDisplayName();
 
 	protected ExtensionRegistry populateNewExtensionRegistryFromExtendWith(AnnotatedElement annotatedElement,
 			ExtensionRegistry existingExtensionRegistry) {

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/MethodTestDescriptor.java

@@ -14,7 +14,6 @@
 import static org.junit.gen5.commons.meta.API.Usage.Internal;
 import static org.junit.gen5.engine.junit5.execution.MethodInvocationContextFactory.methodInvocationContext;
 
-import java.lang.reflect.AnnotatedElement;
 import java.lang.reflect.Method;
 import java.util.List;
 import java.util.Set;
@@ -237,10 +236,9 @@ private void invokeAfterEachCallbacks(ExtensionRegistry registry, TestExtensionC
 	}
 
 	@Override
-	protected String generateDefaultDisplayName(AnnotatedElement element) {
-		Method method = (Method) element;
-		return String.format("%s(%s)", method.getName(),
-			StringUtils.nullSafeToString(Class::getSimpleName, method.getParameterTypes()));
+	protected String generateDefaultDisplayName() {
+		return String.format("%s(%s)", this.testMethod.getName(),
+			StringUtils.nullSafeToString(Class::getSimpleName, this.testMethod.getParameterTypes()));
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/NestedClassTestDescriptor.java

@@ -12,7 +12,6 @@
 
 import static org.junit.gen5.commons.meta.API.Usage.Internal;
 
-import java.lang.reflect.AnnotatedElement;
 import java.util.Set;
 
 import org.junit.gen5.api.extension.ExtensionContext;
@@ -62,9 +61,8 @@ public final Set<TestTag> getTags() {
 	}
 
 	@Override
-	protected String generateDefaultDisplayName(AnnotatedElement element) {
-		Class<?> testClass = (Class<?>) element;
-		return testClass.getSimpleName();
+	protected String generateDefaultDisplayName() {
+		return getTestClass().getSimpleName();
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/TestFactoryTestDescriptor.java

@@ -34,7 +34,6 @@
 import org.junit.gen5.engine.junit5.execution.JUnit5EngineExecutionContext;
 import org.junit.gen5.engine.junit5.execution.MethodInvoker;
 import org.junit.gen5.engine.junit5.execution.ThrowableCollector;
-import org.junit.gen5.engine.support.hierarchical.Leaf;
 import org.junit.gen5.engine.support.hierarchical.SingleTestExecutor;
 
 /**
@@ -43,10 +42,12 @@
  * @since 5.0
  */
 @API(Internal)
-public class TestFactoryTestDescriptor extends MethodTestDescriptor implements Leaf<JUnit5EngineExecutionContext> {
+public class TestFactoryTestDescriptor extends MethodTestDescriptor {
 
 	public static final String DYNAMIC_TEST_SEGMENT_TYPE = "dynamic-test";
 
+	private static final SingleTestExecutor singleTestExecutor = new SingleTestExecutor();
+
 	public TestFactoryTestDescriptor(UniqueId uniqueId, Class<?> testClass, Method testMethod) {
 		super(uniqueId, testClass, testMethod);
 	}
@@ -120,7 +121,7 @@ private void registerAndExecute(DynamicTest dynamicTest, int index, EngineExecut
 
 		listener.dynamicTestRegistered(dynamicTestTestDescriptor);
 		listener.executionStarted(dynamicTestTestDescriptor);
-		TestExecutionResult result = new SingleTestExecutor().executeSafely(dynamicTest.getExecutable()::execute);
+		TestExecutionResult result = singleTestExecutor.executeSafely(dynamicTest.getExecutable()::execute);
 		listener.executionFinished(dynamicTestTestDescriptor, result);
 	}