Introduce ApplicationContextFailureProcessor SPI in the TCF

This commit introduces an ApplicationContextFailureProcessor SPI in the
Spring TestContext Framework that allows third parties to process
failures that occur while a SmartContextLoader attempts to load an
ApplicationContext.

SmartContextLoader implementations must introduce a try-catch block
around the loading code and throw a ContextLoadException that wraps
the failed ApplicationContext and the cause of the failure.

Extensions of AbstractTestContextBootstrapper can configure an
ApplicationContextFailureProcessor by overriding the new protected
getApplicationContextFailureProcessor() method.

DefaultCacheAwareContextLoaderDelegate unwraps any ContextLoadException
and delegates to the configured ApplicationContextFailureProcessor for
processing.

Closes gh-28826

spring-test/src/test/java/org/springframework/test/context/failures/ContextLoadFailureTests.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright 2002-2022 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.failures;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.platform.testkit.engine.EngineTestKit;
+
+import org.springframework.beans.BeanInstantiationException;
+import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.test.context.ApplicationContextFailureProcessor;
+import org.springframework.test.context.BootstrapWith;
+import org.springframework.test.context.junit.jupiter.FailingTestCase;
+import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
+import org.springframework.test.context.support.DefaultTestContextBootstrapper;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.platform.engine.discovery.DiscoverySelectors.selectClass;
+
+/**
+ * Tests for failures that occur while loading an {@link ApplicationContext}.
+ *
+ * @author Sam Brannen
+ * @since 6.0
+ */
+class ContextLoadFailureTests {
+
+	static List<LoadFailure> loadFailures = new ArrayList<>();
+
+
+	@BeforeEach
+	@AfterEach
+	void clearFailures() {
+		loadFailures.clear();
+	}
+
+	@Test
+	void customBootstrapperAppliesApplicationContextFailureProcessor() {
+		assertThat(loadFailures).isEmpty();
+
+		EngineTestKit.engine("junit-jupiter")
+				.selectors(selectClass(ExplosiveContextTestCase.class))//
+				.execute()
+				.testEvents()
+				.assertStatistics(stats -> stats.started(1).succeeded(0).failed(1));
+
+		assertThat(loadFailures).hasSize(1);
+		LoadFailure loadFailure = loadFailures.get(0);
+		assertThat(loadFailure.context()).isExactlyInstanceOf(GenericApplicationContext.class);
+		assertThat(loadFailure.exception())
+				.isInstanceOf(BeanCreationException.class)
+				.cause().isInstanceOf(BeanInstantiationException.class)
+				.rootCause().isInstanceOf(StackOverflowError.class).hasMessage("Boom!");
+	}
+
+
+	@FailingTestCase
+	@SpringJUnitConfig
+	@BootstrapWith(CustomTestContextBootstrapper.class)
+	static class ExplosiveContextTestCase {
+
+		@Test
+		void test1() {
+			/* no-op */
+		}
+
+		@Configuration(proxyBeanMethods = false)
+		static class Config {
+
+			@Bean
+			String explosion() {
+				throw new StackOverflowError("Boom!");
+			}
+		}
+	}
+
+	static class CustomTestContextBootstrapper extends DefaultTestContextBootstrapper {
+
+		@Override
+		protected ApplicationContextFailureProcessor getApplicationContextFailureProcessor() {
+			return (context, exception) -> loadFailures.add(new LoadFailure(context, exception));
+		}
+	}
+
+	record LoadFailure(ApplicationContext context, Throwable exception) {}
+
+}