Support @TestConstructor config via JUnit Platform config param

This commit introduces support for setting the
spring.test.constructor.autowire.mode property via a JUnit Platform
configuration parameter -- for example, via the
junit-platform.properties file.

Closes gh-24285

spring-test/src/main/java/org/springframework/test/context/TestConstructor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,11 @@ import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.lang.Nullable;
+
 /**
  * {@code @TestConstructor} is a type-level annotation that is used to configure
  * how the parameters of a test class constructor are autowired from components
@@ -78,6 +83,9 @@ public @interface TestConstructor {
 	 * <p>May alternatively be configured via the
 	 * {@link org.springframework.core.SpringProperties SpringProperties}
 	 * mechanism.
+	 * <p>As of Spring Framework 5.3, this property may also be configured as a
+	 * <a href="https://junit.org/junit5/docs/current/user-guide/#running-tests-config-params">JUnit
+	 * Platform configuration parameter</a>.
 	 * @see #autowireMode
 	 */
 	String TEST_CONSTRUCTOR_AUTOWIRE_MODE_PROPERTY_NAME = "spring.test.constructor.autowire.mode";
@@ -124,6 +132,31 @@ public @interface TestConstructor {
 		 */
 		ANNOTATED;
 
+
+		private static final Log logger = LogFactory.getLog(AutowireMode.class);
+
+		/**
+		 * Get the {@code AutowireMode} enum constant with the supplied name,
+		 * ignoring case.
+		 *
+		 * @param name the name of the enum constant to retrieve
+		 * @return the corresponding enum constant or {@code null} if not found
+		 * @since 5.3
+		 * @see AutowireMode#valueOf(String)
+		 */
+		@Nullable
+		public static AutowireMode from(@Nullable String name) {
+			try {
+				return AutowireMode.valueOf(name.trim().toUpperCase());
+			}
+			catch (Exception ex) {
+				if (logger.isDebugEnabled()) {
+					logger.debug(String.format("Failed to parse autowire mode from '%s': %s", name,
+						ex.getMessage()));
+				}
+			}
+			return null;
+		}
 	}
 
 }

spring-test/src/main/java/org/springframework/test/context/junit/jupiter/SpringExtension.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -39,6 +39,7 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.lang.Nullable;
 import org.springframework.test.context.TestConstructor;
 import org.springframework.test.context.TestContextManager;
+import org.springframework.test.context.support.PropertyProvider;
 import org.springframework.test.context.support.TestConstructorUtils;
 import org.springframework.util.Assert;
 
@@ -148,8 +149,10 @@ public class SpringExtension implements BeforeAllCallback, AfterAllCallback, Tes
 	 * <ol>
 	 * <li>The {@linkplain ParameterContext#getDeclaringExecutable() declaring
 	 * executable} is a {@link Constructor} and
-	 * {@link TestConstructorUtils#isAutowirableConstructor(Constructor, Class)}
-	 * returns {@code true}.</li>
+	 * {@link TestConstructorUtils#isAutowirableConstructor(Constructor, Class, PropertyProvider)}
+	 * returns {@code true}. Note that {@code isAutowirableConstructor()} will be
+	 * invoked with a fallback {@link PropertyProvider} that delegates its lookup
+	 * to {@link ExtensionContext#getConfigurationParameter(String)}.</li>
 	 * <li>The parameter is of type {@link ApplicationContext} or a sub-type thereof.</li>
 	 * <li>{@link ParameterResolutionDelegate#isAutowirable} returns {@code true}.</li>
 	 * </ol>
@@ -167,7 +170,9 @@ public class SpringExtension implements BeforeAllCallback, AfterAllCallback, Tes
 		Parameter parameter = parameterContext.getParameter();
 		Executable executable = parameter.getDeclaringExecutable();
 		Class<?> testClass = extensionContext.getRequiredTestClass();
-		return (TestConstructorUtils.isAutowirableConstructor(executable, testClass) ||
+		PropertyProvider junitPropertyProvider = propertyName ->
+				extensionContext.getConfigurationParameter(propertyName).orElse(null);
+		return (TestConstructorUtils.isAutowirableConstructor(executable, testClass, junitPropertyProvider) ||
 				ApplicationContext.class.isAssignableFrom(parameter.getType()) ||
 				ParameterResolutionDelegate.isAutowirable(parameter, parameterContext.getIndex()));
 	}

spring-test/src/main/java/org/springframework/test/context/support/PropertyProvider.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright 2002-2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.test.context.support;
+
+import org.springframework.lang.Nullable;
+
+/**
+ * Strategy for providing named properties — for example, for looking up
+ * key-value pairs in a generic fashion.
+ *
+ * <p>Primarily intended for use within the framework.
+ *
+ * @author Sam Brannen
+ * @since 5.3
+ */
+@FunctionalInterface
+public interface PropertyProvider {
+
+	/**
+	 * Get the value of the named property.
+	 *
+	 * @param name the name of the property to retrieve
+	 * @return the value of the property or {@code null} if not found
+	 */
+	@Nullable
+	String get(String name);
+
+}

spring-test/src/main/java/org/springframework/test/context/support/TestConstructorUtils.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2020 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -19,12 +19,10 @@ package org.springframework.test.context.support;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Executable;
 
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.core.SpringProperties;
 import org.springframework.core.annotation.AnnotatedElementUtils;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.TestConstructor;
 import org.springframework.test.context.TestConstructor.AutowireMode;
 
@@ -39,9 +37,6 @@ import org.springframework.test.context.TestConstructor.AutowireMode;
  */
 public abstract class TestConstructorUtils {
 
-	private static final Log logger = LogFactory.getLog(TestConstructorUtils.class);
-
-
 	private TestConstructorUtils() {
 	}
 
@@ -49,17 +44,55 @@ public abstract class TestConstructorUtils {
 	 * Determine if the supplied executable for the given test class is an
 	 * autowirable constructor.
 	 *
-	 * <p>This method delegates to {@link #isAutowirableConstructor(Constructor, Class)}
-	 * if the executable is a constructor.
+	 * <p>This method delegates to {@link #isAutowirableConstructor(Executable, Class, PropertyProvider)}
+	 * will a value of {@code null} for the fallback {@link PropertyProvider}.
 	 *
 	 * @param executable an executable for the test class
 	 * @param testClass the test class
 	 * @return {@code true} if the executable is an autowirable constructor
-	 * @see #isAutowirableConstructor(Constructor, Class)
+	 * @see #isAutowirableConstructor(Executable, Class, PropertyProvider)
 	 */
 	public static boolean isAutowirableConstructor(Executable executable, Class<?> testClass) {
+		return isAutowirableConstructor(executable, testClass, null);
+	}
+
+	/**
+	 * Determine if the supplied constructor for the given test class is
+	 * autowirable.
+	 *
+	 * <p>This method delegates to {@link #isAutowirableConstructor(Constructor, Class, PropertyProvider)}
+	 * will a value of {@code null} for the fallback {@link PropertyProvider}.
+	 *
+	 * @param constructor a constructor for the test class
+	 * @param testClass the test class
+	 * @return {@code true} if the constructor is autowirable
+	 * @see #isAutowirableConstructor(Constructor, Class, PropertyProvider)
+	 */
+	public static boolean isAutowirableConstructor(Constructor<?> constructor, Class<?> testClass) {
+		return isAutowirableConstructor(constructor, testClass, null);
+	}
+
+	/**
+	 * Determine if the supplied executable for the given test class is an
+	 * autowirable constructor.
+	 *
+	 * <p>This method delegates to {@link #isAutowirableConstructor(Constructor, Class, PropertyProvider)}
+	 * if the supplied executable is a constructor and otherwise returns {@code false}.
+	 *
+	 * @param executable an executable for the test class
+	 * @param testClass the test class
+	 * @param fallbackPropertyProvider fallback property provider used to look up
+	 * the value for {@link TestConstructor#TEST_CONSTRUCTOR_AUTOWIRE_MODE_PROPERTY_NAME}
+	 * if no such value is found in {@link SpringProperties}
+	 * @return {@code true} if the executable is an autowirable constructor
+	 * @since 5.3
+	 * @see #isAutowirableConstructor(Constructor, Class, PropertyProvider)
+	 */
+	public static boolean isAutowirableConstructor(Executable executable, Class<?> testClass,
+			@Nullable PropertyProvider fallbackPropertyProvider) {
+
 		return (executable instanceof Constructor &&
-				isAutowirableConstructor((Constructor<?>) executable, testClass));
+				isAutowirableConstructor((Constructor<?>) executable, testClass, fallbackPropertyProvider));
 	}
 
 	/**
@@ -75,17 +108,23 @@ public abstract class TestConstructorUtils {
 	 * <em>meta-present</em> on the test class with
 	 * {@link TestConstructor#autowireMode() autowireMode} set to
 	 * {@link AutowireMode#ALL ALL}.</li>
-	 * <li>The default <em>test constructor autowire mode</em> has been changed
-	 * to {@code ALL} (see
+	 * <li>The default <em>test constructor autowire mode</em> has been set to
+	 * {@code ALL} in {@link SpringProperties} or in the supplied fallback
+	 * {@link PropertyProvider} (see
 	 * {@link TestConstructor#TEST_CONSTRUCTOR_AUTOWIRE_MODE_PROPERTY_NAME}).</li>
 	 * </ol>
 	 *
 	 * @param constructor a constructor for the test class
 	 * @param testClass the test class
+	 * @param fallbackPropertyProvider fallback property provider used to look up
+	 * the value for the default <em>test constructor autowire mode</em> if no
+	 * such value is found in {@link SpringProperties}
 	 * @return {@code true} if the constructor is autowirable
-	 * @see #isAutowirableConstructor(Executable, Class)
+	 * @since 5.3
 	 */
-	public static boolean isAutowirableConstructor(Constructor<?> constructor, Class<?> testClass) {
+	public static boolean isAutowirableConstructor(Constructor<?> constructor, Class<?> testClass,
+			@Nullable PropertyProvider fallbackPropertyProvider) {
+
 		// Is the constructor annotated with @Autowired?
 		if (AnnotatedElementUtils.hasAnnotation(constructor, Autowired.class)) {
 			return true;
@@ -99,18 +138,14 @@ public abstract class TestConstructorUtils {
 			autowireMode = testConstructor.autowireMode();
 		}
 		else {
-			// Custom global default?
+			// Custom global default from SpringProperties?
 			String value = SpringProperties.getProperty(TestConstructor.TEST_CONSTRUCTOR_AUTOWIRE_MODE_PROPERTY_NAME);
-			if (value != null) {
-				try {
-					autowireMode = AutowireMode.valueOf(value.trim().toUpperCase());
-				}
-				catch (Exception ex) {
-					if (logger.isDebugEnabled()) {
-						logger.debug(String.format("Failed to parse autowire mode '%s' for property '%s': %s", value,
-							TestConstructor.TEST_CONSTRUCTOR_AUTOWIRE_MODE_PROPERTY_NAME, ex.getMessage()));
-					}
-				}
+			autowireMode = AutowireMode.from(value);
+
+			// Use fallback provider?
+			if (autowireMode == null && fallbackPropertyProvider != null) {
+				value = fallbackPropertyProvider.get(TestConstructor.TEST_CONSTRUCTOR_AUTOWIRE_MODE_PROPERTY_NAME);
+				autowireMode = AutowireMode.from(value);
 			}
 		}