Clean up warnings

junit-engine-api/src/main/java/org/junit/gen5/engine/EngineDescriptor.java

@@ -10,9 +10,9 @@
 
 package org.junit.gen5.engine;
 
-import java.util.ArrayList;
-import java.util.List;
-
+/**
+ * @since 5.0
+ */
 public class EngineDescriptor extends AbstractTestDescriptor {
 
 	private final TestEngine engine;

junit-launcher/src/main/java/org/junit/gen5/launcher/Launcher.java

@@ -10,13 +10,12 @@
 
 package org.junit.gen5.launcher;
 
-import static org.junit.gen5.launcher.TestEngineRegistry.lookupAllTestEngines;
+import static org.junit.gen5.launcher.TestEngineRegistry.*;
 
 import java.util.Optional;
 
 import org.junit.gen5.engine.EngineDescriptor;
 import org.junit.gen5.engine.EngineExecutionContext;
-import org.junit.gen5.engine.TestDescriptor;
 import org.junit.gen5.engine.TestEngine;
 import org.junit.gen5.engine.TestExecutionListener;
 import org.junit.gen5.engine.TestPlanSpecification;
@@ -65,4 +64,5 @@ public void execute(TestPlan testPlan) {
 		}
 		testPlanExecutionListener.testPlanExecutionFinished(testPlan);
 	}
+
 }

junit4-engine/src/main/java/org/junit/gen5/engine/junit4/JUnit4SpecificationResolver.java

@@ -10,14 +10,10 @@
 
 package org.junit.gen5.engine.junit4;
 
-import java.util.LinkedHashSet;
-import java.util.Set;
-
 import lombok.Data;
 
 import org.junit.gen5.commons.util.ReflectionUtils;
 import org.junit.gen5.engine.EngineDescriptor;
-import org.junit.gen5.engine.TestDescriptor;
 import org.junit.gen5.engine.TestPlanSpecificationVisitor;
 import org.junit.internal.runners.ErrorReportingRunner;
 import org.junit.runner.Description;
@@ -61,4 +57,5 @@ private void addRecursively(JUnit4TestDescriptor parent) {
 			addRecursively(testDescriptor);
 		}
 	}
-}
+
+}

junit4-engine/src/main/java/org/junit/gen5/engine/junit4/JUnit4TestEngine.java

@@ -10,7 +10,7 @@
 
 package org.junit.gen5.engine.junit4;
 
-import static java.util.function.Function.identity;
+import static java.util.function.Function.*;
 import static java.util.stream.Collectors.*;
 
 import java.util.ArrayList;
@@ -68,7 +68,7 @@ private void applyEngineFilters(List<EngineFilter> engineFilters, EngineDescript
 	@Override
 	public void execute(EngineExecutionContext context) {
 
-		//Todo: Use capabilities of engine node to build up tree or to visit nodes
+		// TODO Use capabilities of engine node to build up tree or to visit nodes
 		List<TestDescriptor> originalTestDescriptors = new ArrayList<>(context.getEngineDescriptor().allChildren());
 
 		//@formatter:off

junit4-engine/src/main/java/org/junit/gen5/engine/junit4/RunnerTestDescriptor.java

@@ -10,17 +10,14 @@
 
 package org.junit.gen5.engine.junit4;
 
-import lombok.Value;
-
-import org.junit.gen5.engine.EngineDescriptor;
 import org.junit.runner.Description;
 import org.junit.runner.Runner;
 
 class RunnerTestDescriptor extends JUnit4TestDescriptor {
 
 	final Runner runner;
 
-	Description description;
+	final Description description;
 
 	RunnerTestDescriptor(Runner runner) {
 		// TODO Use unique ID if set, too
@@ -37,4 +34,5 @@ public Description getDescription() {
 	public Runner getRunner() {
 		return runner;
 	}
+
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/JUnit5TestEngine.java

@@ -10,16 +10,7 @@
 
 package org.junit.gen5.engine.junit5;
 
-import static java.util.stream.Collectors.toList;
-
-import java.util.ArrayList;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.LinkedHashSet;
-import java.util.LinkedList;
 import java.util.List;
-import java.util.Map;
-import java.util.Set;
 
 import org.junit.gen5.commons.util.Preconditions;
 import org.junit.gen5.engine.ClassFilter;

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/descriptor/JUnit5Testable.java

@@ -12,8 +12,6 @@
 
 import java.lang.reflect.Method;
 
-import org.junit.gen5.engine.AbstractTestDescriptor;
-
 abstract class JUnit5Testable {
 
 	static JUnit5Testable fromUniqueId(String uniqueId, String engineId) {

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

@@ -15,24 +15,24 @@
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.List;
-import java.util.Optional;
 
 import org.junit.gen5.commons.util.ReflectionUtils;
 import org.junit.gen5.engine.AbstractTestDescriptor;
 import org.junit.gen5.engine.EngineDescriptor;
 import org.junit.gen5.engine.TestDescriptor;
 import org.junit.gen5.engine.TestPlanSpecificationElement;
 import org.junit.gen5.engine.TestPlanSpecificationVisitor;
-import org.junit.gen5.engine.junit5.testers.CanBeTestClass;
 import org.junit.gen5.engine.junit5.testers.IsTestClassWithTests;
 import org.junit.gen5.engine.junit5.testers.IsTestContext;
 import org.junit.gen5.engine.junit5.testers.IsTestMethod;
 
+/**
+ * @since 5.0
+ */
 public class SpecificationResolver {
 
 	private final EngineDescriptor engineDescriptor;
 
-	private final CanBeTestClass canBeTestClass = new CanBeTestClass();
 	private final IsTestContext isTestContext = new IsTestContext();
 	private final IsTestMethod isTestMethod = new IsTestMethod();
 	private final IsTestClassWithTests isTestClassWithTests = new IsTestClassWithTests();
@@ -183,12 +183,8 @@ private ClassTestDescriptor getOrCreateClassDescriptor(Class<?> clazz, String un
 	}
 
 	private TestDescriptor descriptorByUniqueId(String uniqueId) {
-		//Todo: Users of this method should use Optional directly but I couldn't figure out how.
-		Optional<TestDescriptor> optional = engineDescriptor.findByUniqueId(uniqueId);
-		if (optional.isPresent())
-			return optional.get();
-		else
-			return null;
+		// TODO Users of this method should use Optional directly but I couldn't figure out how.
+		return engineDescriptor.findByUniqueId(uniqueId).orElse(null);
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/execution/ContextTestExecutionNode.java

@@ -24,7 +24,8 @@
 /**
  * @since 5.0
  */
-// Todo: Implement execution of inner contexts
+// TODO Implement execution of inner contexts.
+@SuppressWarnings("unused")
 class ContextTestExecutionNode extends TestExecutionNode {
 
 	static final String TEST_INSTANCE_ATTRIBUTE_NAME = ContextTestExecutionNode.class.getName() + ".TestInstance";

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/testers/CanBeTestClass.java

@@ -18,12 +18,9 @@
 public class CanBeTestClass extends ReflectionObjectTester implements Predicate<Class<?>> {
 
 	@Override
-	public boolean test(Class<?> testClassCandidate) {
-		if (isAbstract(testClassCandidate))
-			return false;
-		if (testClassCandidate.isMemberClass() && !isStatic(testClassCandidate))
-			return false;
-		return (!testClassCandidate.isLocalClass());
+	public boolean test(Class<?> candidate) {
+		return !isAbstract(candidate) && !candidate.isLocalClass()
+				&& (isStatic(candidate) || !candidate.isMemberClass());
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/testers/IsTestClassWithTests.java

@@ -10,6 +10,8 @@
 
 package org.junit.gen5.engine.junit5.testers;
 
+import static org.junit.gen5.commons.util.ReflectionUtils.MethodSortOrder.HierarchyDown;
+
 import java.util.function.Predicate;
 
 import org.junit.gen5.commons.util.ReflectionUtils;
@@ -19,19 +21,17 @@
  */
 public class IsTestClassWithTests extends ReflectionObjectTester implements Predicate<Class<?>> {
 
-	private IsTestMethod isTestMethod = new IsTestMethod();
-	private CanBeTestClass canBeTestClass = new CanBeTestClass();
+	private static final IsTestMethod isTestMethod = new IsTestMethod();
+
+	private static final CanBeTestClass canBeTestClass = new CanBeTestClass();
 
 	@Override
 	public boolean test(Class<?> testClassCandidate) {
-		if (!canBeTestClass.test(testClassCandidate))
-			return false;
-		return hasTestMethods(testClassCandidate);
+		return canBeTestClass.test(testClassCandidate) && hasTestMethods(testClassCandidate);
 	}
 
 	private boolean hasTestMethods(Class<?> testClassCandidate) {
-		return !ReflectionUtils.findMethods(testClassCandidate, isTestMethod,
-			ReflectionUtils.MethodSortOrder.HierarchyDown).isEmpty();
+		return !ReflectionUtils.findMethods(testClassCandidate, isTestMethod, HierarchyDown).isEmpty();
 	}
 
 }

junit5-engine/src/main/java/org/junit/gen5/engine/junit5/testers/IsTestMethod.java

@@ -22,10 +22,9 @@
 public class IsTestMethod extends ReflectionObjectTester implements Predicate<Method> {
 
 	@Override
-	public boolean test(Method testMethodCandidate) {
-		if (isPrivate(testMethodCandidate))
-			return false;
-		return hasAnnotation(testMethodCandidate, Test.class);
+	public boolean test(Method candidate) {
+		return !isStatic(candidate) && !isPrivate(candidate) && !isAbstract(candidate)
+				&& hasAnnotation(candidate, Test.class);
 	}
 
 }

junit5-engine/src/test/java/org/junit/gen5/engine/junit5/descriptor/SpecificationResolverTest.java

@@ -12,9 +12,7 @@
 
 import static org.junit.Assert.*;
 
-import java.util.HashSet;
 import java.util.List;
-import java.util.Set;
 import java.util.stream.Collectors;
 
 import org.junit.gen5.api.Context;

junit5-engine/src/test/java/org/junit/gen5/engine/junit5/stubs/TestEngineStub.java

@@ -12,7 +12,6 @@
 
 import org.junit.gen5.engine.EngineDescriptor;
 import org.junit.gen5.engine.EngineExecutionContext;
-import org.junit.gen5.engine.TestDescriptor;
 import org.junit.gen5.engine.TestEngine;
 import org.junit.gen5.engine.TestPlanSpecification;
 
@@ -36,4 +35,5 @@ public void discoverTests(TestPlanSpecification specification, EngineDescriptor
 	@Override
 	public void execute(EngineExecutionContext context) {
 	}
-}
+
+}