Document AOT workaround for @⁠PersistenceContext & @⁠PersistenceUnit in tests

Although @⁠PersistenceContext and @⁠PersistenceUnit are still not
supported in tests running in AOT mode, as of Spring Framework 7.0,
developers can inject an EntityManager or EntityManagerFactory into
tests using @⁠Autowired instead of @⁠PersistenceContext and
@⁠PersistenceUnit, respectively.

See commit 096303c477
See gh-33414
Closes gh-31442

framework-docs/modules/ROOT/pages/testing/testcontext-framework/aot.adoc

@@ -43,6 +43,16 @@ alternative, you can set the same property via the
 xref:appendix.adoc#appendix-spring-properties[`SpringProperties`] mechanism.
 ====
 
+[TIP]
+====
+JPA's `@PersistenceContext` and `@PersistenceUnit` annotations cannot be used to perform
+dependency injection within test classes in AOT mode.
+
+However, as of Spring Framework 7.0, you can inject an `EntityManager` or
+`EntityManagerFactory` into tests using `@Autowired` instead of `@PersistenceContext` and
+`@PersistenceUnit`, respectively.
+====
+
 [NOTE]
 ====
 The `@ContextHierarchy` annotation is not supported in AOT mode.

spring-test/src/test/java/org/springframework/test/context/aot/AotIntegrationTests.java

@@ -147,7 +147,9 @@ class AotIntegrationTests extends AbstractAotTests {
 				// We only include test classes named *Tests so that we don't pick up
 				// internal TestCase classes that aren't really tests.
 				.filter(clazz -> clazz.getSimpleName().endsWith("Tests"))
-				// TestNG EJB tests use @PersistenceContext which is not yet supported in tests in AOT mode.
+				// TestNG EJB tests use @EJB which is not supported in tests in AOT mode, and
+				// since @DisabledInAotMode is not able to disable TestNG tests at runtime,
+				// we have to filter out those tests here.
 				.filter(clazz -> !clazz.getPackageName().contains("testng.transaction.ejb"))
 				// AOT processing works for ParameterizedDependencyInjectionTests by itself
 				// but fails for an unknown reason within the entire spring-test module.

spring-test/src/test/java/org/springframework/test/context/testng/transaction/ejb/AbstractEjbTxDaoTestNGTests.java

@@ -18,10 +18,10 @@ package org.springframework.test.context.testng.transaction.ejb;
 
 import jakarta.ejb.EJB;
 import jakarta.persistence.EntityManager;
-import jakarta.persistence.PersistenceContext;
 import org.testng.annotations.AfterMethod;
 import org.testng.annotations.Test;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.annotation.DirtiesContext.ClassMode;
 import org.springframework.test.context.testng.AbstractTransactionalTestNGSpringContextTests;
@@ -45,7 +45,7 @@ abstract class AbstractEjbTxDaoTestNGTests extends AbstractTransactionalTestNGSp
 	@EJB
 	protected TestEntityDao dao;
 
-	@PersistenceContext
+	@Autowired
 	protected EntityManager em;
 
 

spring-test/src/test/java/org/springframework/test/context/transaction/ejb/AbstractEjbTxDaoTests.java

@@ -18,12 +18,13 @@ package org.springframework.test.context.transaction.ejb;
 
 import jakarta.ejb.EJB;
 import jakarta.persistence.EntityManager;
-import jakarta.persistence.PersistenceContext;
+import jakarta.persistence.EntityManagerFactory;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.MethodOrderer;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.TestMethodOrder;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.annotation.DirtiesContext.ClassMode;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -51,9 +52,14 @@ abstract class AbstractEjbTxDaoTests {
 	@EJB
 	protected TestEntityDao dao;
 
-	@PersistenceContext
+	@Autowired
 	protected EntityManager em;
 
+	// The EntityManagerFactory is not actually used by tests. We only declare it
+	// to ensure that dependency injection works for it.
+	@Autowired
+	protected EntityManagerFactory emf;
+
 
 	@Test
 	void test1InitialState() {