Fail on error by default during test AOT processing

Prior to this commit, if an error was encountered during build-time AOT
processing, the error was logged at WARN/DEBUG level, and processing
continued.

With this commit, test AOT processing now fails on error by default. In
addition, the `failOnError` mode can be disabled by setting the
`spring.test.aot.processing.failOnError` Spring/System property to
`false`.

Closes gh-30977

framework-docs/modules/ROOT/pages/appendix.adoc

@@ -55,6 +55,11 @@ for details.
 {api-spring-framework}++/objenesis/SpringObjenesis.html#IGNORE_OBJENESIS_PROPERTY_NAME++[`SpringObjenesis`]
 for details.
 
+| `spring.test.aot.processing.failOnError`
+| A boolean flag that controls whether errors encountered during AOT processing in the
+_Spring TestContext Framework_ should result in an exception that fails the overall process.
+See xref:testing/testcontext-framework/aot.adoc[Ahead of Time Support for Tests].
+
 | `spring.test.constructor.autowire.mode`
 | The default _test constructor autowire mode_ to use if `@TestConstructor` is not present
 on a test class. See xref:testing/annotations/integration-junit-jupiter.adoc#integration-testing-annotations-testconstructor[Changing the default test constructor autowire mode].

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

@@ -19,7 +19,22 @@ following features.
   use an AOT-optimized `ApplicationContext` that participates transparently with the
   xref:testing/testcontext-framework/ctx-management/caching.adoc[context cache].
 
-[WARNING]
+[TIP]
+====
+By default, if an error is encountered during build-time AOT processing, an exception
+will be thrown, and the overall process will fail immediately.
+
+If you would prefer that build-time AOT processing continue after errors are encountered,
+you can disable the `failOnError` mode which results in errors being logged at `WARN`
+level or with greater detail at `DEBUG` level.
+
+The `failOnError` mode can be disabled from the command line or a build script by setting
+a JVM system property named `spring.test.aot.processing.failOnError` to `false`. As an
+alternative, you can set the same property via the
+xref:appendix.adoc#appendix-spring-properties[`SpringProperties`] mechanism.
+====
+
+[NOTE]
 ====
 The `@ContextHierarchy` annotation is currently not supported in AOT mode.
 ====

spring-test/src/main/java/org/springframework/test/context/aot/TestContextAotGenerator.java

@@ -43,6 +43,7 @@
 import org.springframework.context.annotation.ImportRuntimeHints;
 import org.springframework.context.aot.ApplicationContextAotGenerator;
 import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.core.SpringProperties;
 import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.annotation.MergedAnnotations;
 import org.springframework.core.annotation.MergedAnnotations.SearchStrategy;
@@ -56,6 +57,7 @@
 import org.springframework.util.Assert;
 import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
+import org.springframework.util.StringUtils;
 
 import static org.springframework.aot.hint.MemberCategory.INVOKE_DECLARED_CONSTRUCTORS;
 import static org.springframework.aot.hint.MemberCategory.INVOKE_PUBLIC_METHODS;
@@ -70,8 +72,26 @@
  */
 public class TestContextAotGenerator {
 
+	/**
+	 * JVM system property used to set the {@code failOnError} flag: {@value}.
+	 * <p>The {@code failOnError} flag controls whether errors encountered during
+	 * AOT processing in the <em>Spring TestContext Framework</em> should result
+	 * in an exception that fails the overall process.
+	 * <p>Defaults to {@code true}.
+	 * <p>Supported values include {@code true} or {@code false}, ignoring case.
+	 * For example, the default may be changed to {@code false} by supplying
+	 * the following JVM system property via the command line.
+	 * <pre style="code">-Dspring.test.aot.processing.failOnError=false</pre>
+	 * <p>May alternatively be configured via the
+	 * {@link org.springframework.core.SpringProperties SpringProperties}
+	 * mechanism.
+	 * @since 6.1
+	 */
+	public static final String FAIL_ON_ERROR_PROPERTY_NAME = "spring.test.aot.processing.failOnError";
+
 	private static final Log logger = LogFactory.getLog(TestContextAotGenerator.class);
 
+
 	private final ApplicationContextAotGenerator aotGenerator = new ApplicationContextAotGenerator();
 
 	private final AotServices<TestRuntimeHintsRegistrar> testRuntimeHintsRegistrars;
@@ -85,13 +105,14 @@ public class TestContextAotGenerator {
 
 	private final RuntimeHints runtimeHints;
 
-	private final boolean failOnError;
+	final boolean failOnError;
 
 
 	/**
 	 * Create a new {@link TestContextAotGenerator} that uses the supplied
 	 * {@link GeneratedFiles}.
 	 * @param generatedFiles the {@code GeneratedFiles} to use
+	 * @see #TestContextAotGenerator(GeneratedFiles, RuntimeHints)
 	 */
 	public TestContextAotGenerator(GeneratedFiles generatedFiles) {
 		this(generatedFiles, new RuntimeHints());
@@ -100,11 +121,15 @@ public TestContextAotGenerator(GeneratedFiles generatedFiles) {
 	/**
 	 * Create a new {@link TestContextAotGenerator} that uses the supplied
 	 * {@link GeneratedFiles} and {@link RuntimeHints}.
+	 * <p>This constructor looks up the value of the {@code failOnError} flag via
+	 * the {@value #FAIL_ON_ERROR_PROPERTY_NAME} property, defaulting to
+	 * {@code true} if the property is not set.
 	 * @param generatedFiles the {@code GeneratedFiles} to use
 	 * @param runtimeHints the {@code RuntimeHints} to use
+	 * @see #TestContextAotGenerator(GeneratedFiles, RuntimeHints, boolean)
 	 */
 	public TestContextAotGenerator(GeneratedFiles generatedFiles, RuntimeHints runtimeHints) {
-		this(generatedFiles, runtimeHints, false);
+		this(generatedFiles, runtimeHints, getFailOnErrorFlag());
 	}
 
 	/**
@@ -114,9 +139,9 @@ public TestContextAotGenerator(GeneratedFiles generatedFiles, RuntimeHints runti
 	 * @param runtimeHints the {@code RuntimeHints} to use
 	 * @param failOnError {@code true} if errors encountered during AOT processing
 	 * should result in an exception that fails the overall process
-	 * @since 6.0.12
+	 * @since 6.1
 	 */
-	TestContextAotGenerator(GeneratedFiles generatedFiles, RuntimeHints runtimeHints, boolean failOnError) {
+	public TestContextAotGenerator(GeneratedFiles generatedFiles, RuntimeHints runtimeHints, boolean failOnError) {
 		this.testRuntimeHintsRegistrars = AotServices.factories().load(TestRuntimeHintsRegistrar.class);
 		this.generatedFiles = generatedFiles;
 		this.runtimeHints = runtimeHints;
@@ -368,4 +393,12 @@ private void registerDeclaredConstructors(Class<?> type) {
 		this.runtimeHints.reflection().registerType(type, INVOKE_DECLARED_CONSTRUCTORS);
 	}
 
+	private static boolean getFailOnErrorFlag() {
+		String failOnError = SpringProperties.getProperty(FAIL_ON_ERROR_PROPERTY_NAME);
+		if (StringUtils.hasText(failOnError)) {
+			return Boolean.parseBoolean(failOnError.trim());
+		}
+		return true;
+	}
+
 }

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

@@ -87,7 +87,7 @@ void endToEndTests() {
 
 		// AOT BUILD-TIME: PROCESSING
 		InMemoryGeneratedFiles generatedFiles = new InMemoryGeneratedFiles();
-		TestContextAotGenerator generator = new TestContextAotGenerator(generatedFiles, new RuntimeHints(), true);
+		TestContextAotGenerator generator = new TestContextAotGenerator(generatedFiles, new RuntimeHints());
 		generator.processAheadOfTime(testClasses);
 
 		List<String> sourceFiles = generatedFiles.getGeneratedFiles(Kind.SOURCE).keySet().stream().toList();

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

@@ -0,0 +1,68 @@
+/*
+ * 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.aot;
+
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
+
+import org.springframework.core.SpringProperties;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.test.context.aot.TestContextAotGenerator.FAIL_ON_ERROR_PROPERTY_NAME;
+
+/**
+ * Unit tests for {@link TestContextAotGenerator}.
+ *
+ * @author Sam Brannen
+ * @since 6.1
+ */
+class TestContextAotGeneratorUnitTests {
+
+	@BeforeEach
+	@AfterEach
+	void resetFlag() {
+		SpringProperties.setProperty(FAIL_ON_ERROR_PROPERTY_NAME, null);
+	}
+
+	@Test
+	void failOnErrorEnabledByDefault() {
+		assertThat(createGenerator().failOnError).isTrue();
+	}
+
+	@ParameterizedTest
+	@ValueSource(strings = {"true", "  True\t"})
+	void failOnErrorEnabledViaSpringProperty(String value) {
+		SpringProperties.setProperty(FAIL_ON_ERROR_PROPERTY_NAME, value);
+		assertThat(createGenerator().failOnError).isTrue();
+	}
+
+	@ParameterizedTest
+	@ValueSource(strings = {"false", "  False\t", "x"})
+	void failOnErrorDisabledViaSpringProperty(String value) {
+		SpringProperties.setProperty(FAIL_ON_ERROR_PROPERTY_NAME, value);
+		assertThat(createGenerator().failOnError).isFalse();
+	}
+
+
+	private static TestContextAotGenerator createGenerator() {
+		return new TestContextAotGenerator(null);
+	}
+
+}