Validate that test & lifecycle methods are not @Autowired

Prior to this commit, a developer may have accidentally annotated a
JUnit Jupiter test method or lifecycle method with @Autowired, and that
would have potentially resulted in an exception that was hard to
understand. This is because the Spring container considers any
@Autowired method to be a "configuration method" when autowiring the
test class instance. Consequently, such an @Autowired method would be
invoked twice: once by Spring while attempting to autowire the test
instance and another time by JUnit Jupiter when invoking the test or
lifecycle method. The autowiring invocation of the method often leads
to an exception, either because Spring cannot satisfy a dependency (such
as JUnit Jupiter's TestInfo) or because the body of the method fails due
to test setup that has not yet been invoked.

This commit introduces validation for @Autowired test and lifecycle
methods in the SpringExtension that will throw an IllegalStateException
if any @Autowired method in a test class is also annotated with any of
the following JUnit Jupiter annotations.

- @Test
- @TestFactory
- @TestTemplate
- @RepeatedTest
- @ParameterizedTest
- @BeforeAll
- @AfterAll
- @BeforeEach
- @AfterEach

Closes gh-25966

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

@@ -16,11 +16,19 @@
 
 package org.springframework.test.context.junit.jupiter;
 
+import java.lang.annotation.Annotation;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Executable;
 import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
 import java.lang.reflect.Parameter;
+import java.util.Arrays;
+import java.util.List;
 
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.extension.AfterAllCallback;
 import org.junit.jupiter.api.extension.AfterEachCallback;
 import org.junit.jupiter.api.extension.AfterTestExecutionCallback;
@@ -33,15 +41,22 @@ import org.junit.jupiter.api.extension.ExtensionContext.Store;
 import org.junit.jupiter.api.extension.ParameterContext;
 import org.junit.jupiter.api.extension.ParameterResolver;
 import org.junit.jupiter.api.extension.TestInstancePostProcessor;
+import org.junit.platform.commons.annotation.Testable;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.ParameterResolutionDelegate;
 import org.springframework.context.ApplicationContext;
+import org.springframework.core.annotation.MergedAnnotations;
+import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
+import org.springframework.core.annotation.RepeatableContainers;
 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;
+import org.springframework.util.ReflectionUtils;
+import org.springframework.util.ReflectionUtils.MethodFilter;
 
 /**
  * {@code SpringExtension} integrates the <em>Spring TestContext Framework</em>
@@ -64,10 +79,29 @@ public class SpringExtension implements BeforeAllCallback, AfterAllCallback, Tes
 		ParameterResolver {
 
 	/**
-	 * {@link Namespace} in which {@code TestContextManagers} are stored,
-	 * keyed by test class.
+	 * {@link Namespace} in which {@code TestContextManagers} are stored, keyed
+	 * by test class.
 	 */
-	private static final Namespace NAMESPACE = Namespace.create(SpringExtension.class);
+	private static final Namespace TEST_CONTEXT_MANAGER_NAMESPACE = Namespace.create(SpringExtension.class);
+
+	/**
+	 * {@link Namespace} in which {@code @Autowired} validation error messages
+	 * are stored, keyed by test class.
+	 */
+	private static final Namespace AUTOWIRED_VALIDATION_NAMESPACE = Namespace.create(SpringExtension.class.getName() +
+			"#autowired.validation");
+
+	private static final String NO_AUTOWIRED_VIOLATIONS_DETECTED = "NO AUTOWIRED VIOLATIONS DETECTED";
+
+	// Note that @Test, @TestFactory, @TestTemplate, @RepeatedTest, and @ParameterizedTest
+	// are all meta-annotated with @Testable.
+	private static final List<Class<? extends Annotation>> JUPITER_ANNOTATION_TYPES =
+			Arrays.asList(BeforeAll.class, AfterAll.class, BeforeEach.class, AfterEach.class, Testable.class);
+
+	private static final MethodFilter autowiredTestOrLifecycleMethodFilter = method ->
+			(ReflectionUtils.USER_DECLARED_METHODS.matches(method) &&
+				!Modifier.isPrivate(method.getModifiers()) &&
+				isAutowiredTestOrLifecycleMethod(method));
 
 
 	/**
@@ -93,12 +127,42 @@ public class SpringExtension implements BeforeAllCallback, AfterAllCallback, Tes
 
 	/**
 	 * Delegates to {@link TestContextManager#prepareTestInstance}.
+	 * <p>As of Spring Framework 5.3.2, this method also validates that test
+	 * methods and test lifecycle methods are not annotated with
+	 * {@link Autowired @Autowired}.
 	 */
 	@Override
 	public void postProcessTestInstance(Object testInstance, ExtensionContext context) throws Exception {
+		validateAutowiredConfig(context);
 		getTestContextManager(context).prepareTestInstance(testInstance);
 	}
 
+	/**
+	 * Validate that test methods and test lifecycle methods in the supplied
+	 * test class are not annotated with {@link Autowired @Autowired}.
+	 * @since 5.3.2
+	 */
+	private void validateAutowiredConfig(ExtensionContext context) {
+		// We save the result in the ExtensionContext.Store so that we don't
+		// re-validate all methods for the same test class multiple times.
+		Store store = context.getStore(AUTOWIRED_VALIDATION_NAMESPACE);
+		String errorMessage = store.getOrComputeIfAbsent(context.getRequiredTestClass(),
+			testClass -> {
+				Method[] methodsWithErrors =
+						ReflectionUtils.getUniqueDeclaredMethods(testClass, autowiredTestOrLifecycleMethodFilter);
+				return (methodsWithErrors.length == 0 ? NO_AUTOWIRED_VIOLATIONS_DETECTED :
+						String.format(
+							"Test methods and test lifecycle methods must not be annotated with @Autowired. " +
+							"You should instead annotate individual method parameters with @Autowired, " +
+							"@Qualifier, or @Value. Offending methods in test class %s: %s",
+							testClass.getName(), Arrays.toString(methodsWithErrors)));
+			}, String.class);
+
+		if (errorMessage != NO_AUTOWIRED_VIOLATIONS_DETECTED) {
+			throw new IllegalStateException(errorMessage);
+		}
+	}
+
 	/**
 	 * Delegates to {@link TestContextManager#beforeTestMethod}.
 	 */
@@ -219,7 +283,21 @@ public class SpringExtension implements BeforeAllCallback, AfterAllCallback, Tes
 	}
 
 	private static Store getStore(ExtensionContext context) {
-		return context.getRoot().getStore(NAMESPACE);
+		return context.getRoot().getStore(TEST_CONTEXT_MANAGER_NAMESPACE);
+	}
+
+	private static boolean isAutowiredTestOrLifecycleMethod(Method method) {
+		MergedAnnotations mergedAnnotations =
+				MergedAnnotations.from(method, SearchStrategy.DIRECT, RepeatableContainers.none());
+		if (!mergedAnnotations.isPresent(Autowired.class)) {
+			return false;
+		}
+		for (Class<? extends Annotation> annotationType : JUPITER_ANNOTATION_TYPES) {
+			if (mergedAnnotations.isPresent(annotationType)) {
+				return true;
+			}
+		}
+		return false;
 	}
 
 }