Overhaul TestExecutionListener for Micrometer ObservationRegistry

This commit overhauls the TestExecutionListener for Micrometer's
ObservationRegistry that was introduced in the previous commit.

Specifically, this commit:

- Renames the listener to MicrometerObservationRegistryTestExecutionListener
  since the use of a ThreadLocal is an implementation detail that may
  change over time.

- Makes the listener package-private instead of public in order to
  allow the team greater flexibility in evolving this feature.

- Eagerly loads the ObservationThreadLocalAccessor class and verifies
  that it has a getObservationRegistry() method to ensure that the
  listener is properly skipped when SpringFactoriesLoader attempts to
  load it, if Micrometer 1.10.8+ is not on the classpath.

- Switches the listener's automatic registration order to 2500 in order
  to register it after the DependencyInjectionTestExecutionListener.

- Only tracks the previous ObservationRegistry in beforeTestMethod() if
  the test's ApplicationContext contains an ObservationRegistry bean.

- Properly removes the TestContext attribute for the previous
  ObservationRegistry in afterTestMethod().

- Introduces DEBUG logging for diagnostics.

- Adds an entry in the Javadoc for TestExecutionListener as well as in
  the Testing chapter in the reference manual.

Closes gh-30658

framework-docs/modules/ROOT/pages/testing/testcontext-framework/tel-config.adoc

@@ -12,6 +12,8 @@ by default, exactly in the following order:
   xref:testing/testcontext-framework/application-events.adoc[`ApplicationEvents`].
 * `DependencyInjectionTestExecutionListener`: Provides dependency injection for the test
   instance.
+* `MicrometerObservationRegistryTestExecutionListener`: Provides support for
+  Micrometer's `ObservationRegistry`.
 * `DirtiesContextTestExecutionListener`: Handles the `@DirtiesContext` annotation for
   "`after`" modes.
 * `TransactionalTestExecutionListener`: Provides transactional test execution with

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

@@ -68,6 +68,8 @@ package org.springframework.test.context;
  * ApplicationEventsTestExecutionListener}</li>
  * <li>{@link org.springframework.test.context.support.DependencyInjectionTestExecutionListener
  * DependencyInjectionTestExecutionListener}</li>
+ * <li>{@link org.springframework.test.context.observation.MicrometerObservationRegistryTestExecutionListener
+ * MicrometerObservationRegistryTestExecutionListener}</li>
  * <li>{@link org.springframework.test.context.support.DirtiesContextTestExecutionListener
  * DirtiesContextTestExecutionListener}</li>
  * <li>{@link org.springframework.test.context.transaction.TransactionalTestExecutionListener

spring-test/src/main/java/org/springframework/test/context/observation/MicrometerObservationRegistryTestExecutionListener.java

@@ -0,0 +1,142 @@
+/*
+ * Copyright 2002-2023 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.observation;
+
+import java.lang.reflect.Method;
+
+import io.micrometer.observation.ObservationRegistry;
+import io.micrometer.observation.contextpropagation.ObservationThreadLocalAccessor;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.junit.platform.launcher.TestExecutionListener;
+
+import org.springframework.context.ApplicationContext;
+import org.springframework.core.Conventions;
+import org.springframework.test.context.TestContext;
+import org.springframework.test.context.support.AbstractTestExecutionListener;
+import org.springframework.util.Assert;
+import org.springframework.util.ReflectionUtils;
+
+/**
+ * {@code TestExecutionListener} which provides support for Micrometer's
+ * {@link ObservationRegistry}.
+ *
+ * <p>This listener updates the {@link ObservationThreadLocalAccessor} with the
+ * {@code ObservationRegistry} obtained from the test's {@link ApplicationContext},
+ * if present.
+ *
+ * @author Marcin Grzejszczak
+ * @author Sam Brannen
+ * @since 6.0.10
+ */
+class MicrometerObservationRegistryTestExecutionListener extends AbstractTestExecutionListener {
+
+	private static final Log logger = LogFactory.getLog(MicrometerObservationRegistryTestExecutionListener.class);
+
+	private static final String OBSERVATION_THREAD_LOCAL_ACCESSOR_CLASS_NAME =
+			"io.micrometer.observation.contextpropagation.ObservationThreadLocalAccessor";
+
+	/**
+	 * Attribute name for a {@link TestContext} attribute which contains the
+	 * {@link ObservationRegistry} that was previously stored in the
+	 * {@link ObservationThreadLocalAccessor}.
+	 * <p>After each test method, the previously stored {@code ObservationRegistry}
+	 * will be restored. If tests run concurrently this might cause issues unless
+	 * the {@code ObservationRegistry} is always the same (which should typically
+	 * be the case).
+	 */
+	private static final String PREVIOUS_OBSERVATION_REGISTRY = Conventions.getQualifiedAttributeName(
+			MicrometerObservationRegistryTestExecutionListener.class, "previousObservationRegistry");
+
+
+	static {
+		// Trigger eager resolution of Micrometer Observation types during static
+		// initialization of this class to ensure that this listener can be properly
+		// skipped when SpringFactoriesLoader attempts to load it, if micrometer-observation
+		// is not in the classpath or if the version of ObservationThreadLocalAccessor
+		// present does not include the getObservationRegistry() method.
+		String errorMessage =
+				"MicrometerObservationRegistryTestExecutionListener requires micrometer-observation 1.10.8 or higher";
+		Class<?> clazz;
+		try {
+			clazz = Class.forName(OBSERVATION_THREAD_LOCAL_ACCESSOR_CLASS_NAME, true,
+					TestExecutionListener.class.getClassLoader());
+		}
+		catch (Throwable ex) {
+			throw new IllegalStateException(errorMessage, ex);
+		}
+
+		Method method = ReflectionUtils.findMethod(clazz, "getObservationRegistry");
+		Assert.state(method != null, errorMessage);
+	}
+
+
+	/**
+	 * Returns {@code 2500}.
+	 */
+	@Override
+	public final int getOrder() {
+		return 2500;
+	}
+
+	/**
+	 * If the test's {@link ApplicationContext} contains an {@link ObservationRegistry}
+	 * bean, this method retrieves the {@code ObservationRegistry} currently stored
+	 * in {@link ObservationThreadLocalAccessor}, saves a reference to the original
+	 * registry as a {@link TestContext} attribute (to be restored in
+	 * {@link #afterTestMethod(TestContext)}), and sets the registry from the test's
+	 * {@code ApplicationContext} in {@link ObservationThreadLocalAccessor}.
+	 * @param testContext the test context for the test; never {@code null}
+	 * @see #afterTestMethod(TestContext)
+	 */
+	@Override
+	public void beforeTestMethod(TestContext testContext) {
+		testContext.getApplicationContext().getBeanProvider(ObservationRegistry.class)
+				.ifAvailable(registry -> {
+					if (logger.isDebugEnabled()) {
+						logger.debug("""
+								Registering ObservationRegistry from ApplicationContext in \
+								ObservationThreadLocalAccessor for test class \
+								""" + testContext.getTestClass().getName());
+					}
+					ObservationThreadLocalAccessor accessor = ObservationThreadLocalAccessor.getInstance();
+					testContext.setAttribute(PREVIOUS_OBSERVATION_REGISTRY, accessor.getObservationRegistry());
+					accessor.setObservationRegistry(registry);
+				});
+	}
+
+	/**
+	 * Retrieves the original {@link ObservationRegistry} that was saved in
+	 * {@link #beforeTestMethod(TestContext)} and sets it in
+	 * {@link ObservationThreadLocalAccessor}.
+	 * @param testContext the test context for the test; never {@code null}
+	 * @see #beforeTestMethod(TestContext)
+	 */
+	@Override
+	public void afterTestMethod(TestContext testContext) {
+		ObservationRegistry previousObservationRegistry =
+				(ObservationRegistry) testContext.removeAttribute(PREVIOUS_OBSERVATION_REGISTRY);
+		if (previousObservationRegistry != null) {
+			if (logger.isDebugEnabled()) {
+				logger.debug("Restoring ObservationRegistry in ObservationThreadLocalAccessor for test class " +
+						testContext.getTestClass().getName());
+			}
+			ObservationThreadLocalAccessor.getInstance().setObservationRegistry(previousObservationRegistry);
+		}
+	}
+
+}

spring-test/src/main/java/org/springframework/test/context/observation/MicrometerObservationThreadLocalTestExecutionListener.java

@@ -1,92 +0,0 @@
-/*
- * Copyright 2002-2023 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.observation;
-
-import io.micrometer.observation.ObservationRegistry;
-import io.micrometer.observation.contextpropagation.ObservationThreadLocalAccessor;
-
-import org.springframework.context.ApplicationContext;
-import org.springframework.core.Conventions;
-import org.springframework.test.context.TestContext;
-import org.springframework.test.context.TestExecutionListener;
-import org.springframework.test.context.support.AbstractTestExecutionListener;
-
-/**
- * {@code ObservationThreadLocalTestExecutionListener} is an implementation of the {@link TestExecutionListener}
- * SPI that updates the {@link ObservationThreadLocalAccessor} with the {@link ObservationRegistry}
- * taken from the {@link ApplicationContext} present in the {@link TestContext}.
- *
- * <p>This implementation is not thread-safe.
- *
- * @author Marcin Grzejszczak
- * @since 6.1
- */
-public class MicrometerObservationThreadLocalTestExecutionListener extends AbstractTestExecutionListener {
-
-	/**
-	 * Attribute name for a {@link TestContext} attribute which contains the previously
-	 * set {@link ObservationRegistry} on the {@link ObservationThreadLocalAccessor}.
-	 * <p>After all tests from the current test class have completed, the previously stored {@link ObservationRegistry}
-	 * will be restored. If tests are ran concurrently this might cause issues
-	 * unless the {@link ObservationRegistry} is always the same (which should be the case most frequently).
-	 */
-	private static final String PREVIOUS_OBSERVATION_REGISTRY = Conventions.getQualifiedAttributeName(
-			MicrometerObservationThreadLocalTestExecutionListener.class, "previousObservationRegistry");
-
-	/**
-	 * Retrieves the current {@link ObservationRegistry} stored
-	 * on {@link ObservationThreadLocalAccessor} instance and stores it
-	 * in the {@link TestContext} attributes and overrides it with
-	 * one stored in {@link ApplicationContext} associated with
-	 * the {@link TestContext}.
-	 * @param testContext the test context for the test; never {@code null}
-	 */
-	@Override
-	public void beforeTestMethod(TestContext testContext) {
-		testContext.setAttribute(PREVIOUS_OBSERVATION_REGISTRY,
-				ObservationThreadLocalAccessor.getInstance().getObservationRegistry());
-		testContext.getApplicationContext()
-				.getBeanProvider(ObservationRegistry.class)
-				.ifAvailable(observationRegistry ->
-						ObservationThreadLocalAccessor.getInstance()
-								.setObservationRegistry(observationRegistry));
-	}
-
-	/**
-	 * Retrieves the previously stored {@link ObservationRegistry} and sets it back
-	 * on the {@link ObservationThreadLocalAccessor} instance.
-	 * @param testContext the test context for the test; never {@code null}
-	 */
-	@Override
-	public void afterTestMethod(TestContext testContext) {
-		ObservationRegistry previousObservationRegistry =
-				(ObservationRegistry) testContext.getAttribute(PREVIOUS_OBSERVATION_REGISTRY);
-		if (previousObservationRegistry != null) {
-			ObservationThreadLocalAccessor.getInstance()
-					.setObservationRegistry(previousObservationRegistry);
-		}
-	}
-
-
-	/**
-	 * Returns {@code 3500}.
-	 */
-	@Override
-	public final int getOrder() {
-		return 3500;
-	}
-}

spring-test/src/main/resources/META-INF/spring.factories

@@ -5,11 +5,11 @@ org.springframework.test.context.TestExecutionListener = \
 	org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener,\
 	org.springframework.test.context.event.ApplicationEventsTestExecutionListener,\
 	org.springframework.test.context.support.DependencyInjectionTestExecutionListener,\
+	org.springframework.test.context.observation.MicrometerObservationRegistryTestExecutionListener,\
 	org.springframework.test.context.support.DirtiesContextTestExecutionListener,\
 	org.springframework.test.context.transaction.TransactionalTestExecutionListener,\
 	org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener,\
-	org.springframework.test.context.event.EventPublishingTestExecutionListener,\
-	org.springframework.test.context.observation.MicrometerObservationThreadLocalTestExecutionListener
+	org.springframework.test.context.event.EventPublishingTestExecutionListener
 
 # Default ContextCustomizerFactory implementations for the Spring TestContext Framework
 #

spring-test/src/test/java/org/springframework/test/context/TestExecutionListenersTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 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.
@@ -28,13 +28,13 @@ import org.springframework.core.annotation.AnnotationConfigurationException;
 import org.springframework.test.context.event.ApplicationEventsTestExecutionListener;
 import org.springframework.test.context.event.EventPublishingTestExecutionListener;
 import org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener;
-import org.springframework.test.context.observation.MicrometerObservationThreadLocalTestExecutionListener;
 import org.springframework.test.context.support.AbstractTestExecutionListener;
 import org.springframework.test.context.support.DependencyInjectionTestExecutionListener;
 import org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener;
 import org.springframework.test.context.support.DirtiesContextTestExecutionListener;
 import org.springframework.test.context.transaction.TransactionalTestExecutionListener;
 import org.springframework.test.context.web.ServletTestExecutionListener;
+import org.springframework.util.ClassUtils;
 
 import static java.util.Arrays.asList;
 import static java.util.stream.Collectors.toList;
@@ -57,14 +57,17 @@ import static org.springframework.test.context.TestExecutionListeners.MergeMode.
  */
 class TestExecutionListenersTests {
 
+	private static final Class<?> micrometerListenerClass =
+			ClassUtils.resolveClassName("org.springframework.test.context.observation.MicrometerObservationRegistryTestExecutionListener", null);
+
 	@Test
 	void defaultListeners() {
 		List<Class<?>> expected = asList(ServletTestExecutionListener.class,//
 				DirtiesContextBeforeModesTestExecutionListener.class,//
 				ApplicationEventsTestExecutionListener.class,//
 				DependencyInjectionTestExecutionListener.class,//
+				micrometerListenerClass,//
 				DirtiesContextTestExecutionListener.class,//
-				MicrometerObservationThreadLocalTestExecutionListener.class,//
 				TransactionalTestExecutionListener.class,//
 				SqlScriptsTestExecutionListener.class,//
 				EventPublishingTestExecutionListener.class
@@ -82,8 +85,8 @@ class TestExecutionListenersTests {
 				DirtiesContextBeforeModesTestExecutionListener.class,//
 				ApplicationEventsTestExecutionListener.class,//
 				DependencyInjectionTestExecutionListener.class,//
+				micrometerListenerClass,//
 				DirtiesContextTestExecutionListener.class,//
-				MicrometerObservationThreadLocalTestExecutionListener.class,//
 				TransactionalTestExecutionListener.class,//
 				SqlScriptsTestExecutionListener.class,//
 				EventPublishingTestExecutionListener.class
@@ -100,8 +103,8 @@ class TestExecutionListenersTests {
 				DirtiesContextBeforeModesTestExecutionListener.class,//
 				ApplicationEventsTestExecutionListener.class,//
 				DependencyInjectionTestExecutionListener.class,//
+				micrometerListenerClass,//
 				DirtiesContextTestExecutionListener.class,//
-				MicrometerObservationThreadLocalTestExecutionListener.class,//
 				TransactionalTestExecutionListener.class,
 				SqlScriptsTestExecutionListener.class,//
 				EventPublishingTestExecutionListener.class,//
@@ -120,8 +123,8 @@ class TestExecutionListenersTests {
 				ApplicationEventsTestExecutionListener.class,//
 				DependencyInjectionTestExecutionListener.class,//
 				BarTestExecutionListener.class,//
+				micrometerListenerClass,//
 				DirtiesContextTestExecutionListener.class,//
-				MicrometerObservationThreadLocalTestExecutionListener.class,//
 				TransactionalTestExecutionListener.class,//
 				SqlScriptsTestExecutionListener.class,//
 				EventPublishingTestExecutionListener.class
@@ -366,9 +369,9 @@ class TestExecutionListenersTests {
 
 		@Override
 		public int getOrder() {
-			// 2500 is between DependencyInjectionTestExecutionListener (2000) and
-			// DirtiesContextTestExecutionListener (3000)
-			return 2500;
+			// 2250 is between DependencyInjectionTestExecutionListener (2000) and
+			// MicrometerObservationRegistryTestExecutionListener (2500)
+			return 2250;
 		}
 	}
 

spring-test/src/test/java/org/springframework/test/context/observation/MicrometerObservationRegistryTestExecutionListenerTests.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright 2002-2023 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.observation;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import io.micrometer.observation.ObservationRegistry;
+import io.micrometer.observation.contextpropagation.ObservationThreadLocalAccessor;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.context.support.StaticApplicationContext;
+import org.springframework.test.context.TestContext;
+import org.springframework.test.context.TestExecutionListener;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
+import static org.mockito.BDDMockito.given;
+import static org.mockito.BDDMockito.willAnswer;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Unit tests for {@link MicrometerObservationRegistryTestExecutionListener}.
+ *
+ * @author Marcin Grzejszczak
+ * @author Sam Brannen
+ * @since 6.0.10
+ */
+class MicrometerObservationRegistryTestExecutionListenerTests {
+
+	private final ObservationRegistry originalObservationRegistry = globalObservationRegistry();
+
+	private final TestContext testContext = mock();
+
+	private final StaticApplicationContext applicationContext = new StaticApplicationContext();
+
+	private final Map<String, Object> attributes = new HashMap<>();
+
+	private final TestExecutionListener listener = new MicrometerObservationRegistryTestExecutionListener();
+
+
+	@BeforeEach
+	@SuppressWarnings({ "unchecked", "rawtypes" }) // for raw Class testClass
+	void configureTestContextMock() {
+		willAnswer(invocation -> attributes.put(invocation.getArgument(0), invocation.getArgument(1)))
+				.given(testContext).setAttribute(anyString(), any());
+		given(testContext.removeAttribute(anyString()))
+				.willAnswer(invocation -> attributes.get(invocation.getArgument(0, String.class)));
+		given(testContext.getApplicationContext()).willReturn(applicationContext);
+		Class testClass = getClass();
+		given(testContext.getTestClass()).willReturn(testClass);
+	}
+
+	@Test
+	void observationRegistryIsNotOverridden() throws Exception {
+		assertGlobalObservationRegistryIsSameAsOriginal();
+
+		listener.beforeTestMethod(testContext);
+		assertGlobalObservationRegistryIsSameAsOriginal();
+
+		listener.afterTestMethod(testContext);
+		assertGlobalObservationRegistryIsSameAsOriginal();
+	}
+
+	@Test
+	void observationRegistryIsOverriddenByBeanFromApplicationContext() throws Exception {
+		assertGlobalObservationRegistryIsSameAsOriginal();
+
+		ObservationRegistry testObservationRegistry = ObservationRegistry.create();
+		applicationContext.getDefaultListableBeanFactory().registerSingleton("observationRegistry", testObservationRegistry);
+
+		listener.beforeTestMethod(testContext);
+		ObservationRegistry globalObservationRegistry = globalObservationRegistry();
+		assertThat(globalObservationRegistry)
+				.as("The global ObservationRegistry should have been replaced with the one from the application context")
+				.isNotSameAs(originalObservationRegistry)
+				.isSameAs(testObservationRegistry);
+
+		listener.afterTestMethod(testContext);
+		assertGlobalObservationRegistryIsSameAsOriginal();
+	}
+
+	private void assertGlobalObservationRegistryIsSameAsOriginal() {
+		assertThat(globalObservationRegistry()).isSameAs(originalObservationRegistry);
+	}
+
+	private static ObservationRegistry globalObservationRegistry() {
+		return ObservationThreadLocalAccessor.getInstance().getObservationRegistry();
+	}
+
+}

spring-test/src/test/java/org/springframework/test/context/observation/MicrometerObservationThreadLocalTestExecutionListenerTests.java

@@ -1,84 +0,0 @@
-/*
- * Copyright 2002-2023 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.observation;
-
-import java.util.HashMap;
-import java.util.Map;
-
-import io.micrometer.observation.ObservationRegistry;
-import io.micrometer.observation.contextpropagation.ObservationThreadLocalAccessor;
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import org.springframework.context.support.StaticApplicationContext;
-import org.springframework.test.context.TestContext;
-
-import static org.assertj.core.api.BDDAssertions.then;
-import static org.mockito.ArgumentMatchers.any;
-import static org.mockito.ArgumentMatchers.anyString;
-import static org.mockito.BDDMockito.given;
-import static org.mockito.BDDMockito.willAnswer;
-import static org.mockito.Mockito.mock;
-
-class MicrometerObservationThreadLocalTestExecutionListenerTests {
-
-	ObservationRegistry originalObservationRegistry = ObservationThreadLocalAccessor.getInstance().getObservationRegistry();
-
-	TestContext testContext = mock();
-
-	StaticApplicationContext applicationContext = new StaticApplicationContext();
-
-	Map<String, Object> attributes = new HashMap<>();
-
-	MicrometerObservationThreadLocalTestExecutionListener listener = new MicrometerObservationThreadLocalTestExecutionListener();
-
-	@BeforeEach
-	void setup() {
-		willAnswer(invocation -> attributes.put(invocation.getArgument(0), invocation.getArgument(1))).given(testContext).setAttribute(anyString(), any());
-		given(testContext.getAttribute(anyString())).willAnswer(invocation -> attributes.get(invocation.getArgument(0, String.class)));
-		given(testContext.getApplicationContext()).willReturn(applicationContext);
-	}
-
-	@Test
-	void observationRegistryShouldNotBeOverridden() throws Exception {
-		listener.beforeTestMethod(testContext);
-		thenObservationRegistryOnOTLAIsSameAsOriginal();
-		listener.afterTestMethod(testContext);
-		thenObservationRegistryOnOTLAIsSameAsOriginal();
-	}
-
-	@Test
-	void observationRegistryOverriddenByBeanFromTestContext() throws Exception {
-		ObservationRegistry newObservationRegistry = ObservationRegistry.create();
-		applicationContext.getDefaultListableBeanFactory().registerSingleton("observationRegistry", newObservationRegistry);
-
-		listener.beforeTestMethod(testContext);
-		ObservationRegistry otlaObservationRegistry = ObservationThreadLocalAccessor.getInstance().getObservationRegistry();
-		then(otlaObservationRegistry)
-				.as("During the test we want the original ObservationRegistry to be replaced with the one present in this application context")
-				.isNotSameAs(originalObservationRegistry)
-				.isSameAs(newObservationRegistry);
-
-		listener.afterTestMethod(testContext);
-		thenObservationRegistryOnOTLAIsSameAsOriginal();
-	}
-
-	private void thenObservationRegistryOnOTLAIsSameAsOriginal() {
-		then(ObservationThreadLocalAccessor.getInstance().getObservationRegistry()).isSameAs(originalObservationRegistry);
-	}
-
-}

spring-test/src/test/resources/log4j2-test.xml

@@ -18,6 +18,7 @@
 		<Logger name="org.springframework.test.context.cache" level="warn" />
 		<Logger name="org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate" level="info" />
 		<Logger name="org.springframework.test.context.junit4.rules" level="warn" />
+		<Logger name="org.springframework.test.context.observation" level="warn" />
 		<Logger name="org.springframework.test.context.transaction.TransactionalTestExecutionListener" level="warn" />
 		<Logger name="org.springframework.test.context.web" level="warn" />
 		<!-- The following must be kept at DEBUG in order to test SPR-14363. -->