Introduce JupiterConfiguration interface

The new interface wraps around `ConfigurationParameters` instances and
provides access to as well as conversion for well-known configuration
parameters used by within the Jupiter engine.

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/Constants.java

@@ -18,10 +18,8 @@
 import static org.junit.platform.engine.support.hierarchical.DefaultParallelExecutionConfigurationStrategy.CONFIG_STRATEGY_PROPERTY_NAME;
 
 import org.apiguardian.api.API;
-import org.junit.jupiter.engine.descriptor.ExecutionModeUtils;
-import org.junit.jupiter.engine.descriptor.TestInstanceLifecycleUtils;
+import org.junit.jupiter.engine.config.JupiterConfiguration;
 import org.junit.jupiter.engine.execution.ConditionEvaluator;
-import org.junit.jupiter.engine.extension.ExtensionRegistry;
 import org.junit.platform.engine.support.hierarchical.ParallelExecutionConfigurationStrategy;
 
 /**
@@ -63,7 +61,7 @@ public final class Constants {
 	 * @see #DEACTIVATE_ALL_CONDITIONS_PATTERN
 	 * @see org.junit.jupiter.api.extension.ExecutionCondition
 	 */
-	public static final String DEACTIVATE_CONDITIONS_PATTERN_PROPERTY_NAME = ConditionEvaluator.DEACTIVATE_CONDITIONS_PATTERN_PROPERTY_NAME;
+	public static final String DEACTIVATE_CONDITIONS_PATTERN_PROPERTY_NAME = JupiterConfiguration.DEACTIVATE_CONDITIONS_PATTERN_PROPERTY_NAME;
 
 	/**
 	 * Wildcard pattern which signals that all conditions should be deactivated: {@value}
@@ -79,7 +77,7 @@ public final class Constants {
 	 *
 	 * <p>The default behavior is not to perform auto-detection.
 	 */
-	public static final String EXTENSIONS_AUTODETECTION_ENABLED_PROPERTY_NAME = ExtensionRegistry.EXTENSIONS_AUTODETECTION_ENABLED_PROPERTY_NAME;
+	public static final String EXTENSIONS_AUTODETECTION_ENABLED_PROPERTY_NAME = JupiterConfiguration.EXTENSIONS_AUTODETECTION_ENABLED_PROPERTY_NAME;
 
 	/**
 	 * Property name used to set the default test instance lifecycle mode: {@value}
@@ -94,7 +92,7 @@ public final class Constants {
 	 *
 	 * @see org.junit.jupiter.api.TestInstance
 	 */
-	public static final String DEFAULT_TEST_INSTANCE_LIFECYCLE_PROPERTY_NAME = TestInstanceLifecycleUtils.DEFAULT_TEST_INSTANCE_LIFECYCLE_PROPERTY_NAME;
+	public static final String DEFAULT_TEST_INSTANCE_LIFECYCLE_PROPERTY_NAME = JupiterConfiguration.DEFAULT_TEST_INSTANCE_LIFECYCLE_PROPERTY_NAME;
 
 	/**
 	 * Property name used to enable parallel test execution: {@value}
@@ -104,7 +102,7 @@ public final class Constants {
 	 * @since 5.3
 	 */
 	@API(status = EXPERIMENTAL, since = "5.3")
-	public static final String PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME = "junit.jupiter.execution.parallel.enabled";
+	public static final String PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME = JupiterConfiguration.PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME;
 
 	/**
 	 * Property name used to set the default parallel test execution mode: {@value}
@@ -124,7 +122,7 @@ public final class Constants {
 	 * @since 5.4
 	 */
 	@API(status = EXPERIMENTAL, since = "5.4")
-	public static final String DEFAULT_PARALLEL_EXECUTION_MODE = ExecutionModeUtils.DEFAULT_EXECUTION_MODE_PROPERTY_NAME;
+	public static final String DEFAULT_PARALLEL_EXECUTION_MODE = JupiterConfiguration.DEFAULT_EXECUTION_MODE_PROPERTY_NAME;
 
 	static final String PARALLEL_CONFIG_PREFIX = "junit.jupiter.execution.parallel.config.";
 

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/JupiterTestEngine.java

@@ -15,11 +15,12 @@
 import java.util.Optional;
 
 import org.apiguardian.api.API;
+import org.junit.jupiter.engine.config.DefaultJupiterConfiguration;
+import org.junit.jupiter.engine.config.JupiterConfiguration;
 import org.junit.jupiter.engine.descriptor.JupiterEngineDescriptor;
 import org.junit.jupiter.engine.discovery.DiscoverySelectorResolver;
 import org.junit.jupiter.engine.execution.JupiterEngineExecutionContext;
 import org.junit.jupiter.engine.support.JupiterThrowableCollectorFactory;
-import org.junit.platform.engine.ConfigurationParameters;
 import org.junit.platform.engine.EngineDiscoveryRequest;
 import org.junit.platform.engine.ExecutionRequest;
 import org.junit.platform.engine.TestDescriptor;
@@ -61,26 +62,27 @@ public Optional<String> getArtifactId() {
 
 	@Override
 	public TestDescriptor discover(EngineDiscoveryRequest discoveryRequest, UniqueId uniqueId) {
-		JupiterEngineDescriptor engineDescriptor = new JupiterEngineDescriptor(uniqueId,
+		JupiterConfiguration configuration = new DefaultJupiterConfiguration(
 			discoveryRequest.getConfigurationParameters());
-		new DiscoverySelectorResolver().resolveSelectors(discoveryRequest, engineDescriptor);
+		JupiterEngineDescriptor engineDescriptor = new JupiterEngineDescriptor(uniqueId, configuration);
+		new DiscoverySelectorResolver().resolveSelectors(discoveryRequest, configuration, engineDescriptor);
 		return engineDescriptor;
 	}
 
 	@Override
 	protected HierarchicalTestExecutorService createExecutorService(ExecutionRequest request) {
-		ConfigurationParameters config = request.getConfigurationParameters();
-		if (config.getBoolean(Constants.PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME).orElse(false)) {
-			return new ForkJoinPoolHierarchicalTestExecutorService(
-				new PrefixedConfigurationParameters(config, Constants.PARALLEL_CONFIG_PREFIX));
+		JupiterConfiguration configuration = getJupiterConfiguration(request);
+		if (configuration.isParallelExecutionEnabled()) {
+			return new ForkJoinPoolHierarchicalTestExecutorService(new PrefixedConfigurationParameters(
+				request.getConfigurationParameters(), Constants.PARALLEL_CONFIG_PREFIX));
 		}
 		return super.createExecutorService(request);
 	}
 
 	@Override
 	protected JupiterEngineExecutionContext createExecutionContext(ExecutionRequest request) {
 		return new JupiterEngineExecutionContext(request.getEngineExecutionListener(),
-			request.getConfigurationParameters());
+			getJupiterConfiguration(request));
 	}
 
 	/**
@@ -91,4 +93,9 @@ protected ThrowableCollector.Factory createThrowableCollectorFactory(ExecutionRe
 		return JupiterThrowableCollectorFactory::createThrowableCollector;
 	}
 
+	private JupiterConfiguration getJupiterConfiguration(ExecutionRequest request) {
+		JupiterEngineDescriptor engineDescriptor = (JupiterEngineDescriptor) request.getRootTestDescriptor();
+		return engineDescriptor.getConfiguration();
+	}
+
 }

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/config/DefaultJupiterConfiguration.java

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2015-2018 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package org.junit.jupiter.engine.config;
+
+import static org.apiguardian.api.API.Status.INTERNAL;
+
+import java.util.Optional;
+
+import org.apiguardian.api.API;
+import org.junit.jupiter.api.TestInstance.Lifecycle;
+import org.junit.jupiter.api.parallel.ExecutionMode;
+import org.junit.platform.commons.util.Preconditions;
+import org.junit.platform.commons.util.StringUtils;
+import org.junit.platform.engine.ConfigurationParameters;
+
+@API(status = INTERNAL, since = "5.4")
+public class DefaultJupiterConfiguration implements JupiterConfiguration {
+
+	private final ConfigurationParameters configurationParameters;
+
+	public DefaultJupiterConfiguration(ConfigurationParameters configurationParameters) {
+		this.configurationParameters = Preconditions.notNull(configurationParameters,
+			"ConfigurationParameters must not be null");
+	}
+
+	@Override
+	public Optional<String> getRawConfigurationParameter(String key) {
+		return configurationParameters.get(key);
+	}
+
+	@Override
+	public boolean isParallelExecutionEnabled() {
+		return configurationParameters.getBoolean(PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME).orElse(false);
+	}
+
+	@Override
+	public boolean isExtensionAutoDetectionEnabled() {
+		return configurationParameters.getBoolean(EXTENSIONS_AUTODETECTION_ENABLED_PROPERTY_NAME).orElse(false);
+	}
+
+	@Override
+	public ExecutionMode getDefaultExecutionMode() {
+		EnumConfigurationParameterConverter<ExecutionMode> converter = new EnumConfigurationParameterConverter<>(
+			ExecutionMode.class, "parallel execution mode");
+		return converter.get(configurationParameters, DEFAULT_EXECUTION_MODE_PROPERTY_NAME, ExecutionMode.SAME_THREAD);
+	}
+
+	@Override
+	public Lifecycle getDefaultTestInstanceLifecycle() {
+		EnumConfigurationParameterConverter<Lifecycle> converter = new EnumConfigurationParameterConverter<>(
+			Lifecycle.class, "test instance lifecycle mode");
+		return converter.get(configurationParameters, DEFAULT_TEST_INSTANCE_LIFECYCLE_PROPERTY_NAME,
+			Lifecycle.PER_METHOD);
+	}
+
+	@Override
+	public Optional<String> getDeactivateExecutionConditionsPattern() {
+		// @formatter:off
+        return configurationParameters.get(DEACTIVATE_CONDITIONS_PATTERN_PROPERTY_NAME)
+                .filter(StringUtils::isNotBlank)
+                .map(String::trim);
+        // @formatter:on
+	}
+}

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/EnumConfigurationParameterConverter.java → junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/config/EnumConfigurationParameterConverter.java

@@ -8,7 +8,7 @@
  * http://www.eclipse.org/legal/epl-v20.html
  */
 
-package org.junit.jupiter.engine.descriptor;
+package org.junit.jupiter.engine.config;
 
 import java.util.Optional;
 
@@ -19,7 +19,7 @@
 
 class EnumConfigurationParameterConverter<T extends Enum<T>> {
 
-	private static final Logger logger = LoggerFactory.getLogger(TestInstanceLifecycleUtils.class);
+	private static final Logger logger = LoggerFactory.getLogger(EnumConfigurationParameterConverter.class);
 
 	private final Class<T> enumType;
 	private final String enumDisplayName;

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/config/JupiterConfiguration.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2015-2018 the original author or authors.
+ *
+ * All rights reserved. This program and the accompanying materials are
+ * made available under the terms of the Eclipse Public License v2.0 which
+ * accompanies this distribution and is available at
+ *
+ * http://www.eclipse.org/legal/epl-v20.html
+ */
+
+package org.junit.jupiter.engine.config;
+
+import static org.apiguardian.api.API.Status.INTERNAL;
+
+import java.util.Optional;
+
+import org.apiguardian.api.API;
+import org.junit.jupiter.api.TestInstance;
+import org.junit.jupiter.api.parallel.ExecutionMode;
+
+@API(status = INTERNAL, since = "5.4")
+public interface JupiterConfiguration {
+
+	String DEACTIVATE_CONDITIONS_PATTERN_PROPERTY_NAME = "junit.jupiter.conditions.deactivate";
+	String PARALLEL_EXECUTION_ENABLED_PROPERTY_NAME = "junit.jupiter.execution.parallel.enabled";
+	String DEFAULT_EXECUTION_MODE_PROPERTY_NAME = "junit.jupiter.execution.parallel.mode.default";
+	String EXTENSIONS_AUTODETECTION_ENABLED_PROPERTY_NAME = "junit.jupiter.extensions.autodetection.enabled";
+	String DEFAULT_TEST_INSTANCE_LIFECYCLE_PROPERTY_NAME = "junit.jupiter.testinstance.lifecycle.default";
+
+	Optional<String> getRawConfigurationParameter(String key);
+
+	boolean isParallelExecutionEnabled();
+
+	boolean isExtensionAutoDetectionEnabled();
+
+	ExecutionMode getDefaultExecutionMode();
+
+	TestInstance.Lifecycle getDefaultTestInstanceLifecycle();
+
+	Optional<String> getDeactivateExecutionConditionsPattern();
+
+}

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/config/package-info.java

@@ -0,0 +1,5 @@
+/**
+ * Configuration specific to the JUnit Jupiter test engine.
+ */
+
+package org.junit.jupiter.engine.config;

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/AbstractExtensionContext.java

@@ -20,10 +20,10 @@
 import java.util.Set;
 
 import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.engine.config.JupiterConfiguration;
 import org.junit.jupiter.engine.execution.ExtensionValuesStore;
 import org.junit.jupiter.engine.execution.NamespaceAwareStore;
 import org.junit.platform.commons.util.Preconditions;
-import org.junit.platform.engine.ConfigurationParameters;
 import org.junit.platform.engine.EngineExecutionListener;
 import org.junit.platform.engine.TestDescriptor;
 import org.junit.platform.engine.TestTag;
@@ -38,19 +38,19 @@ abstract class AbstractExtensionContext<T extends TestDescriptor> implements Ext
 	private final EngineExecutionListener engineExecutionListener;
 	private final T testDescriptor;
 	private final Set<String> tags;
-	private final ConfigurationParameters configurationParameters;
+	private final JupiterConfiguration configuration;
 	private final ExtensionValuesStore valuesStore;
 
 	AbstractExtensionContext(ExtensionContext parent, EngineExecutionListener engineExecutionListener, T testDescriptor,
-			ConfigurationParameters configurationParameters) {
+			JupiterConfiguration configuration) {
 
 		Preconditions.notNull(testDescriptor, "TestDescriptor must not be null");
-		Preconditions.notNull(configurationParameters, "ConfigurationParameters must not be null");
+		Preconditions.notNull(configuration, "JupiterConfiguration must not be null");
 
 		this.parent = parent;
 		this.engineExecutionListener = engineExecutionListener;
 		this.testDescriptor = testDescriptor;
-		this.configurationParameters = configurationParameters;
+		this.configuration = configuration;
 		this.valuesStore = createStore(parent);
 
 		// @formatter:off
@@ -119,7 +119,7 @@ public Set<String> getTags() {
 
 	@Override
 	public Optional<String> getConfigurationParameter(String key) {
-		return this.configurationParameters.get(key);
+		return this.configuration.getRawConfigurationParameter(key);
 	}
 
 }

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/ClassExtensionContext.java

@@ -19,7 +19,7 @@
 import org.apiguardian.api.API;
 import org.junit.jupiter.api.TestInstance.Lifecycle;
 import org.junit.jupiter.api.extension.ExtensionContext;
-import org.junit.platform.engine.ConfigurationParameters;
+import org.junit.jupiter.engine.config.JupiterConfiguration;
 import org.junit.platform.engine.EngineExecutionListener;
 import org.junit.platform.engine.support.hierarchical.ThrowableCollector;
 
@@ -38,21 +38,20 @@ public final class ClassExtensionContext extends AbstractExtensionContext<ClassT
 	/**
 	 * Create a new {@code ClassExtensionContext} with {@link Lifecycle#PER_METHOD}.
 	 *
-	 * @see #ClassExtensionContext(ExtensionContext, EngineExecutionListener, ClassTestDescriptor, Lifecycle, ConfigurationParameters, ThrowableCollector)
+	 * @see #ClassExtensionContext(ExtensionContext, EngineExecutionListener, ClassTestDescriptor, Lifecycle, JupiterConfiguration, ThrowableCollector)
 	 */
 	public ClassExtensionContext(ExtensionContext parent, EngineExecutionListener engineExecutionListener,
-			ClassTestDescriptor testDescriptor, ConfigurationParameters configurationParameters,
+			ClassTestDescriptor testDescriptor, JupiterConfiguration configuration,
 			ThrowableCollector throwableCollector) {
 
-		this(parent, engineExecutionListener, testDescriptor, Lifecycle.PER_METHOD, configurationParameters,
-			throwableCollector);
+		this(parent, engineExecutionListener, testDescriptor, Lifecycle.PER_METHOD, configuration, throwableCollector);
 	}
 
 	public ClassExtensionContext(ExtensionContext parent, EngineExecutionListener engineExecutionListener,
-			ClassTestDescriptor testDescriptor, Lifecycle lifecycle, ConfigurationParameters configurationParameters,
+			ClassTestDescriptor testDescriptor, Lifecycle lifecycle, JupiterConfiguration configuration,
 			ThrowableCollector throwableCollector) {
 
-		super(parent, engineExecutionListener, testDescriptor, configurationParameters);
+		super(parent, engineExecutionListener, testDescriptor, configuration);
 
 		this.lifecycle = lifecycle;
 		this.throwableCollector = throwableCollector;

junit-jupiter-engine/src/main/java/org/junit/jupiter/engine/descriptor/ClassTestDescriptor.java

@@ -43,6 +43,7 @@
 import org.junit.jupiter.api.extension.TestInstanceFactory;
 import org.junit.jupiter.api.extension.TestInstancePostProcessor;
 import org.junit.jupiter.api.extension.TestInstantiationException;
+import org.junit.jupiter.engine.config.JupiterConfiguration;
 import org.junit.jupiter.engine.execution.AfterEachMethodAdapter;
 import org.junit.jupiter.engine.execution.BeforeEachMethodAdapter;
 import org.junit.jupiter.engine.execution.ExecutableInvoker;
@@ -53,7 +54,6 @@
 import org.junit.platform.commons.util.BlacklistedExceptions;
 import org.junit.platform.commons.util.ReflectionUtils;
 import org.junit.platform.commons.util.StringUtils;
-import org.junit.platform.engine.ConfigurationParameters;
 import org.junit.platform.engine.TestDescriptor;
 import org.junit.platform.engine.TestTag;
 import org.junit.platform.engine.UniqueId;
@@ -86,17 +86,17 @@ public class ClassTestDescriptor extends JupiterTestDescriptor {
 	private List<Method> beforeAllMethods;
 	private List<Method> afterAllMethods;
 
-	public ClassTestDescriptor(UniqueId uniqueId, Class<?> testClass, ConfigurationParameters configurationParameters) {
-		this(uniqueId, testClass, createDisplayNameSupplierForClass(testClass), configurationParameters);
+	public ClassTestDescriptor(UniqueId uniqueId, Class<?> testClass, JupiterConfiguration configuration) {
+		this(uniqueId, testClass, createDisplayNameSupplierForClass(testClass), configuration);
 	}
 
 	ClassTestDescriptor(UniqueId uniqueId, Class<?> testClass, Supplier<String> displayNameSupplier,
-			ConfigurationParameters configurationParameters) {
-		super(uniqueId, testClass, displayNameSupplier, ClassSource.from(testClass), configurationParameters);
+			JupiterConfiguration configuration) {
+		super(uniqueId, testClass, displayNameSupplier, ClassSource.from(testClass), configuration);
 
 		this.testClass = testClass;
 		this.tags = getTags(testClass);
-		this.lifecycle = getTestInstanceLifecycle(testClass, configurationParameters);
+		this.lifecycle = getTestInstanceLifecycle(testClass, configuration);
 		this.defaultChildExecutionMode = (this.lifecycle == Lifecycle.PER_CLASS ? ExecutionMode.SAME_THREAD : null);
 	}
 
@@ -162,8 +162,7 @@ public JupiterEngineExecutionContext prepare(JupiterEngineExecutionContext conte
 
 		ThrowableCollector throwableCollector = createThrowableCollector();
 		ClassExtensionContext extensionContext = new ClassExtensionContext(context.getExtensionContext(),
-			context.getExecutionListener(), this, this.lifecycle, context.getConfigurationParameters(),
-			throwableCollector);
+			context.getExecutionListener(), this, this.lifecycle, context.getConfiguration(), throwableCollector);
 
 		this.beforeAllMethods = findBeforeAllMethods(this.testClass, this.lifecycle == Lifecycle.PER_METHOD);
 		this.afterAllMethods = findAfterAllMethods(this.testClass, this.lifecycle == Lifecycle.PER_METHOD);