Check that BPP and BFPP bean methods won't cause eager initialization

Closes gh-35164

buildSrc/build.gradle

@@ -38,6 +38,7 @@ dependencies {
 	testImplementation("org.assertj:assertj-core:3.11.1")
 	testImplementation("org.apache.logging.log4j:log4j-core:2.17.1")
 	testImplementation("org.junit.jupiter:junit-jupiter:5.6.0")
+	implementation("org.springframework:spring-context")
 	testRuntimeOnly("org.junit.platform:junit-platform-launcher")
 }
 

buildSrc/src/main/java/org/springframework/boot/build/architecture/ArchitectureCheck.java

@@ -0,0 +1,186 @@
+/*
+ * Copyright 2022-2023 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.boot.build.architecture;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.StandardOpenOption;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+import com.tngtech.archunit.base.DescribedPredicate;
+import com.tngtech.archunit.core.domain.JavaClass;
+import com.tngtech.archunit.core.domain.JavaClass.Predicates;
+import com.tngtech.archunit.core.domain.JavaClasses;
+import com.tngtech.archunit.core.domain.JavaMethod;
+import com.tngtech.archunit.core.domain.JavaParameter;
+import com.tngtech.archunit.core.domain.properties.CanBeAnnotated;
+import com.tngtech.archunit.core.importer.ClassFileImporter;
+import com.tngtech.archunit.lang.ArchCondition;
+import com.tngtech.archunit.lang.ArchRule;
+import com.tngtech.archunit.lang.ConditionEvents;
+import com.tngtech.archunit.lang.EvaluationResult;
+import com.tngtech.archunit.lang.SimpleConditionEvent;
+import com.tngtech.archunit.lang.syntax.ArchRuleDefinition;
+import com.tngtech.archunit.library.dependencies.SlicesRuleDefinition;
+import org.gradle.api.DefaultTask;
+import org.gradle.api.GradleException;
+import org.gradle.api.Task;
+import org.gradle.api.file.DirectoryProperty;
+import org.gradle.api.file.FileCollection;
+import org.gradle.api.file.FileTree;
+import org.gradle.api.tasks.IgnoreEmptyDirectories;
+import org.gradle.api.tasks.InputFiles;
+import org.gradle.api.tasks.Internal;
+import org.gradle.api.tasks.OutputDirectory;
+import org.gradle.api.tasks.PathSensitive;
+import org.gradle.api.tasks.PathSensitivity;
+import org.gradle.api.tasks.SkipWhenEmpty;
+import org.gradle.api.tasks.TaskAction;
+
+/**
+ * {@link Task} that checks for architecture problems.
+ *
+ * @author Andy Wilkinson
+ */
+public abstract class ArchitectureCheck extends DefaultTask {
+
+	private FileCollection classes;
+
+	public ArchitectureCheck() {
+		getOutputDirectory().convention(getProject().getLayout().getBuildDirectory().dir(getName()));
+	}
+
+	@TaskAction
+	void checkArchitecture() throws IOException {
+		JavaClasses javaClasses = new ClassFileImporter()
+			.importPaths(this.classes.getFiles().stream().map(File::toPath).collect(Collectors.toList()));
+		List<EvaluationResult> violations = Stream.of(allPackagesShouldBeFreeOfTangles(),
+				allBeanPostProcessorBeanMethodsShouldBeStaticAndHaveParametersThatWillNotCausePrematureInitialization(),
+				allBeanFactoryPostProcessorBeanMethodsShouldBeStaticAndHaveNoParameters())
+			.map((rule) -> rule.evaluate(javaClasses))
+			.filter(EvaluationResult::hasViolation)
+			.collect(Collectors.toList());
+		File outputFile = getOutputDirectory().file("failure-report.txt").get().getAsFile();
+		outputFile.getParentFile().mkdirs();
+		if (!violations.isEmpty()) {
+			StringBuilder report = new StringBuilder();
+			for (EvaluationResult violation : violations) {
+				report.append(violation.getFailureReport().toString());
+				report.append(String.format("%n"));
+			}
+			Files.write(outputFile.toPath(), report.toString().getBytes(StandardCharsets.UTF_8),
+					StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING);
+			throw new GradleException("Architecture check failed. See '" + outputFile + "' for details.");
+		}
+		else {
+			outputFile.createNewFile();
+		}
+	}
+
+	private ArchRule allPackagesShouldBeFreeOfTangles() {
+		return SlicesRuleDefinition.slices().matching("(**)").should().beFreeOfCycles();
+	}
+
+	private ArchRule allBeanPostProcessorBeanMethodsShouldBeStaticAndHaveParametersThatWillNotCausePrematureInitialization() {
+		return ArchRuleDefinition.methods()
+			.that()
+			.areAnnotatedWith("org.springframework.context.annotation.Bean")
+			.and()
+			.haveRawReturnType(Predicates.assignableTo("org.springframework.beans.factory.config.BeanPostProcessor"))
+			.should(onlyHaveParametersThatWillNotCauseEagerInitialization())
+			.andShould()
+			.beStatic()
+			.allowEmptyShould(true);
+	}
+
+	private ArchCondition<JavaMethod> onlyHaveParametersThatWillNotCauseEagerInitialization() {
+		DescribedPredicate<CanBeAnnotated> notAnnotatedWithLazy = DescribedPredicate
+			.not(CanBeAnnotated.Predicates.annotatedWith("org.springframework.context.annotation.Lazy"));
+		DescribedPredicate<JavaClass> notOfASafeType = DescribedPredicate
+			.not(Predicates.assignableTo("org.springframework.beans.factory.ObjectProvider")
+				.or(Predicates.assignableTo("org.springframework.context.ApplicationContext"))
+				.or(Predicates.assignableTo("org.springframework.core.env.Environment")));
+		return new ArchCondition<JavaMethod>("not have parameters that will cause eager initialization") {
+
+			@Override
+			public void check(JavaMethod item, ConditionEvents events) {
+				item.getParameters()
+					.stream()
+					.filter(notAnnotatedWithLazy)
+					.filter((parameter) -> notOfASafeType.test(parameter.getRawType()))
+					.forEach((parameter) -> events.add(SimpleConditionEvent.violated(parameter,
+							parameter.getDescription() + " will cause eager initialization as it is "
+									+ notAnnotatedWithLazy.getDescription() + " and is "
+									+ notOfASafeType.getDescription())));
+			}
+
+		};
+	}
+
+	private ArchRule allBeanFactoryPostProcessorBeanMethodsShouldBeStaticAndHaveNoParameters() {
+		return ArchRuleDefinition.methods()
+			.that()
+			.areAnnotatedWith("org.springframework.context.annotation.Bean")
+			.and()
+			.haveRawReturnType(
+					Predicates.assignableTo("org.springframework.beans.factory.config.BeanFactoryPostProcessor"))
+			.should(haveNoParameters())
+			.andShould()
+			.beStatic()
+			.allowEmptyShould(true);
+	}
+
+	private ArchCondition<JavaMethod> haveNoParameters() {
+		return new ArchCondition<JavaMethod>("have no parameters") {
+
+			@Override
+			public void check(JavaMethod item, ConditionEvents events) {
+				List<JavaParameter> parameters = item.getParameters();
+				if (!parameters.isEmpty()) {
+					events
+						.add(SimpleConditionEvent.violated(item, item.getDescription() + " should have no parameters"));
+				}
+			}
+
+		};
+	}
+
+	public void setClasses(FileCollection classes) {
+		this.classes = classes;
+	}
+
+	@Internal
+	public FileCollection getClasses() {
+		return this.classes;
+	}
+
+	@InputFiles
+	@SkipWhenEmpty
+	@IgnoreEmptyDirectories
+	@PathSensitive(PathSensitivity.RELATIVE)
+	final FileTree getInputClasses() {
+		return this.classes.getAsFileTree();
+	}
+
+	@OutputDirectory
+	public abstract DirectoryProperty getOutputDirectory();
+
+}

buildSrc/src/main/java/org/springframework/boot/build/architecture/ArchitecturePlugin.java

@@ -44,14 +44,14 @@ public class ArchitecturePlugin implements Plugin<Project> {
 
 	private void registerTasks(Project project) {
 		JavaPluginExtension javaPluginExtension = project.getExtensions().getByType(JavaPluginExtension.class);
-		List<TaskProvider<PackageTangleCheck>> packageTangleChecks = new ArrayList<>();
+		List<TaskProvider<ArchitectureCheck>> packageTangleChecks = new ArrayList<>();
 		for (SourceSet sourceSet : javaPluginExtension.getSourceSets()) {
-			TaskProvider<PackageTangleCheck> checkPackageTangles = project.getTasks()
-				.register("checkForPackageTangles" + StringUtils.capitalize(sourceSet.getName()),
-						PackageTangleCheck.class, (task) -> {
+			TaskProvider<ArchitectureCheck> checkPackageTangles = project.getTasks()
+				.register("checkArchitecture" + StringUtils.capitalize(sourceSet.getName()), ArchitectureCheck.class,
+						(task) -> {
 							task.setClasses(sourceSet.getOutput().getClassesDirs());
-							task.setDescription("Checks the classes of the " + sourceSet.getName()
-									+ " source set for package tangles.");
+							task.setDescription("Checks the architecture of the classes of the " + sourceSet.getName()
+									+ " source set.");
 							task.setGroup(LifecycleBasePlugin.VERIFICATION_GROUP);
 						});
 			packageTangleChecks.add(checkPackageTangles);

buildSrc/src/main/java/org/springframework/boot/build/architecture/PackageTangleCheck.java

@@ -1,102 +0,0 @@
-/*
- * Copyright 2022-2023 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.boot.build.architecture;
-
-import java.io.File;
-import java.io.FileWriter;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.nio.file.Files;
-import java.nio.file.StandardOpenOption;
-import java.util.stream.Collectors;
-
-import com.tngtech.archunit.core.domain.JavaClasses;
-import com.tngtech.archunit.core.importer.ClassFileImporter;
-import com.tngtech.archunit.lang.EvaluationResult;
-import com.tngtech.archunit.library.dependencies.SliceRule;
-import com.tngtech.archunit.library.dependencies.SlicesRuleDefinition;
-import org.gradle.api.DefaultTask;
-import org.gradle.api.GradleException;
-import org.gradle.api.Task;
-import org.gradle.api.file.DirectoryProperty;
-import org.gradle.api.file.FileCollection;
-import org.gradle.api.file.FileTree;
-import org.gradle.api.tasks.IgnoreEmptyDirectories;
-import org.gradle.api.tasks.InputFiles;
-import org.gradle.api.tasks.Internal;
-import org.gradle.api.tasks.OutputDirectory;
-import org.gradle.api.tasks.PathSensitive;
-import org.gradle.api.tasks.PathSensitivity;
-import org.gradle.api.tasks.SkipWhenEmpty;
-import org.gradle.api.tasks.TaskAction;
-
-import org.springframework.util.FileCopyUtils;
-
-/**
- * {@link Task} that checks for package tangles.
- *
- * @author Andy Wilkinson
- */
-public abstract class PackageTangleCheck extends DefaultTask {
-
-	private FileCollection classes;
-
-	public PackageTangleCheck() {
-		getOutputDirectory().convention(getProject().getLayout().getBuildDirectory().dir(getName()));
-	}
-
-	@TaskAction
-	void checkForPackageTangles() throws IOException {
-		JavaClasses javaClasses = new ClassFileImporter()
-			.importPaths(this.classes.getFiles().stream().map(File::toPath).collect(Collectors.toList()));
-		SliceRule freeOfCycles = SlicesRuleDefinition.slices().matching("(**)").should().beFreeOfCycles();
-		EvaluationResult result = freeOfCycles.evaluate(javaClasses);
-		File outputFile = getOutputDirectory().file("failure-report.txt").get().getAsFile();
-		outputFile.getParentFile().mkdirs();
-		if (result.hasViolation()) {
-			Files.write(outputFile.toPath(), result.getFailureReport().toString().getBytes(StandardCharsets.UTF_8),
-					StandardOpenOption.CREATE);
-			FileWriter writer = new FileWriter(outputFile);
-			FileCopyUtils.copy(result.getFailureReport().toString(), writer);
-			throw new GradleException("Package tangle check failed. See '" + outputFile + "' for details.");
-		}
-		else {
-			outputFile.createNewFile();
-		}
-	}
-
-	public void setClasses(FileCollection classes) {
-		this.classes = classes;
-	}
-
-	@Internal
-	public FileCollection getClasses() {
-		return this.classes;
-	}
-
-	@InputFiles
-	@SkipWhenEmpty
-	@IgnoreEmptyDirectories
-	@PathSensitive(PathSensitivity.RELATIVE)
-	final FileTree getInputClasses() {
-		return this.classes.getAsFileTree();
-	}
-
-	@OutputDirectory
-	public abstract DirectoryProperty getOutputDirectory();
-
-}

buildSrc/src/main/java/org/springframework/boot/build/architecture/Rules.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 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.boot.build.architecture;
+
+import java.util.stream.Stream;
+
+import com.tngtech.archunit.base.DescribedPredicate;
+import com.tngtech.archunit.core.domain.JavaClass.Predicates;
+import com.tngtech.archunit.lang.ArchRule;
+import com.tngtech.archunit.lang.syntax.ArchRuleDefinition;
+import com.tngtech.archunit.library.dependencies.SlicesRuleDefinition;
+
+/**
+ * Architecture rules evaluated by {@link ArchitectureCheck}.
+ *
+ * @author Andy Wilkinson
+ */
+final class Rules {
+
+	private Rules() {
+
+	}
+
+	static Stream<ArchRule> stream() {
+		return Stream.of(allPackagesShouldBeFreeOfTangles(),
+				allBeanPostProcessorBeanMethodsShouldBeStaticAndHaveParametersThatWillNotCausePrematureInitialization());
+	}
+
+	static ArchRule allPackagesShouldBeFreeOfTangles() {
+		return SlicesRuleDefinition.slices().matching("(**)").should().beFreeOfCycles();
+	}
+
+	static ArchRule allBeanPostProcessorBeanMethodsShouldBeStaticAndHaveParametersThatWillNotCausePrematureInitialization() {
+		return ArchRuleDefinition.methods()
+			.that()
+			.areAnnotatedWith("org.springframework.context.annotation.Bean")
+			.and()
+			.haveRawReturnType(Predicates.assignableTo("org.springframework.beans.factory.config.BeanPostProcessor"))
+			.should()
+			.beStatic()
+			.andShould()
+			.haveRawParameterTypes(DescribedPredicate
+				.allElements(Predicates.assignableTo("org.springframework.beans.factory.ObjectProvider")
+					.or(Predicates.assignableTo("org.springframework.context.ApplicationContext"))))
+			.allowEmptyShould(true);
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/ArchitectureCheckTests.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture;
+
+import java.io.File;
+import java.io.IOException;
+
+import org.gradle.api.GradleException;
+import org.gradle.api.Project;
+import org.gradle.testfixtures.ProjectBuilder;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import org.springframework.core.io.Resource;
+import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
+import org.springframework.util.FileSystemUtils;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+
+/**
+ * Tests for {@link ArchitectureCheck}.
+ *
+ * @author Andy Wilkinson
+ */
+class ArchitectureCheckTests {
+
+	@TempDir
+	File temp;
+
+	@Test
+	void whenPackagesAreTangledTaskFailsAndWritesAReport() throws Exception {
+		prepareTask("tangled", (architectureCheck) -> {
+			assertThatExceptionOfType(GradleException.class).isThrownBy(() -> architectureCheck.checkArchitecture());
+			assertThat(failureReport(architectureCheck).length()).isGreaterThan(0);
+		});
+	}
+
+	@Test
+	void whenPackagesAreNotTangledTaskSucceedsAndWritesAnEmptyReport() throws Exception {
+		prepareTask("untangled", (architectureCheck) -> {
+			architectureCheck.checkArchitecture();
+			assertThat(failureReport(architectureCheck).length()).isZero();
+		});
+	}
+
+	File failureReport(ArchitectureCheck architectureCheck) {
+		return new File(architectureCheck.getProject().getBuildDir(), "checkArchitecture/failure-report.txt");
+	}
+
+	@Test
+	void whenBeanPostProcessorBeanMethodIsNotStaticTaskFailsAndWritesAReport() throws Exception {
+		prepareTask("bpp/nonstatic", (architectureCheck) -> {
+			assertThatExceptionOfType(GradleException.class).isThrownBy(() -> architectureCheck.checkArchitecture());
+			assertThat(failureReport(architectureCheck).length()).isGreaterThan(0);
+		});
+	}
+
+	@Test
+	void whenBeanPostProcessorBeanMethodIsStaticAndHasUnsafeParametersTaskFailsAndWritesAReport() throws Exception {
+		prepareTask("bpp/unsafeparameters", (architectureCheck) -> {
+			assertThatExceptionOfType(GradleException.class).isThrownBy(() -> architectureCheck.checkArchitecture());
+			assertThat(failureReport(architectureCheck).length()).isGreaterThan(0);
+		});
+	}
+
+	@Test
+	void whenBeanPostProcessorBeanMethodIsStaticAndHasSafeParametersTaskSucceedsAndWritesAnEmptyReport()
+			throws Exception {
+		prepareTask("bpp/safeparameters", (architectureCheck) -> {
+			architectureCheck.checkArchitecture();
+			assertThat(failureReport(architectureCheck).length()).isZero();
+		});
+	}
+
+	@Test
+	void whenBeanPostProcessorBeanMethodIsStaticAndHasNoParametersTaskSucceedsAndWritesAnEmptyReport()
+			throws Exception {
+		prepareTask("bpp/noparameters", (architectureCheck) -> {
+			architectureCheck.checkArchitecture();
+			assertThat(failureReport(architectureCheck).length()).isZero();
+		});
+	}
+
+	@Test
+	void whenBeanFactoryPostProcessorBeanMethodIsNotStaticTaskFailsAndWritesAReport() throws Exception {
+		prepareTask("bfpp/nonstatic", (architectureCheck) -> {
+			assertThatExceptionOfType(GradleException.class).isThrownBy(() -> architectureCheck.checkArchitecture());
+			assertThat(failureReport(architectureCheck).length()).isGreaterThan(0);
+		});
+	}
+
+	@Test
+	void whenBeanFactoryPostProcessorBeanMethodIsStaticAndHasParametersTaskFailsAndWritesAReport() throws Exception {
+		prepareTask("bfpp/parameters", (architectureCheck) -> {
+			assertThatExceptionOfType(GradleException.class).isThrownBy(() -> architectureCheck.checkArchitecture());
+			assertThat(failureReport(architectureCheck).length()).isGreaterThan(0);
+		});
+	}
+
+	@Test
+	void whenBeanFactoryPostProcessorBeanMethodIsStaticAndHasNoParametersTaskSucceedsAndWritesAnEmptyReport()
+			throws Exception {
+		prepareTask("bfpp/noparameters", (architectureCheck) -> {
+			architectureCheck.checkArchitecture();
+			assertThat(failureReport(architectureCheck).length()).isZero();
+		});
+	}
+
+	private void prepareTask(String classes, Callback<ArchitectureCheck> callback) throws Exception {
+		File projectDir = new File(this.temp, "project");
+		projectDir.mkdirs();
+		copyClasses(classes, projectDir);
+		Project project = ProjectBuilder.builder().withProjectDir(projectDir).build();
+		ArchitectureCheck architectureCheck = project.getTasks()
+			.create("checkArchitecture", ArchitectureCheck.class, (task) -> task.setClasses(project.files("classes")));
+		callback.accept(architectureCheck);
+	}
+
+	private void copyClasses(String name, File projectDir) throws IOException {
+		PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
+		Resource root = resolver.getResource("classpath:org/springframework/boot/build/architecture/" + name);
+		FileSystemUtils.copyRecursively(root.getFile(),
+				new File(projectDir, "classes/org/springframework/boot/build/architecture/" + name));
+
+	}
+
+	private interface Callback<T> {
+
+		void accept(T item) throws Exception;
+
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/PackageTangleCheckTests.java

@@ -1,93 +0,0 @@
-/*
- * Copyright 2012-2023 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.boot.build.architecture;
-
-import java.io.File;
-import java.io.IOException;
-
-import org.gradle.api.GradleException;
-import org.gradle.api.Project;
-import org.gradle.testfixtures.ProjectBuilder;
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.io.TempDir;
-
-import org.springframework.core.io.Resource;
-import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
-import org.springframework.util.FileSystemUtils;
-
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
-
-/**
- * Tests for {@link PackageTangleCheck}.
- *
- * @author Andy Wilkinson
- */
-class PackageTangleCheckTests {
-
-	@TempDir
-	File temp;
-
-	@Test
-	void whenPackagesAreTangledTaskFailsAndWritesAReport() throws Exception {
-		prepareTask("tangled", (packageTangleCheck) -> {
-			assertThatExceptionOfType(GradleException.class)
-				.isThrownBy(() -> packageTangleCheck.checkForPackageTangles());
-			assertThat(
-					new File(packageTangleCheck.getProject().getBuildDir(), "checkForPackageTangles/failure-report.txt")
-						.length())
-				.isGreaterThan(0);
-		});
-	}
-
-	@Test
-	void whenPackagesAreNotTangledTaskSucceedsAndWritesAnEmptyReport() throws Exception {
-		prepareTask("untangled", (packageTangleCheck) -> {
-			packageTangleCheck.checkForPackageTangles();
-			assertThat(
-					new File(packageTangleCheck.getProject().getBuildDir(), "checkForPackageTangles/failure-report.txt")
-						.length())
-				.isEqualTo(0);
-		});
-	}
-
-	private void prepareTask(String classes, Callback<PackageTangleCheck> callback) throws Exception {
-		File projectDir = new File(this.temp, "project");
-		projectDir.mkdirs();
-		copyClasses(classes, projectDir);
-		Project project = ProjectBuilder.builder().withProjectDir(projectDir).build();
-		PackageTangleCheck packageTangleCheck = project.getTasks()
-			.create("checkForPackageTangles", PackageTangleCheck.class,
-					(task) -> task.setClasses(project.files("classes")));
-		callback.accept(packageTangleCheck);
-	}
-
-	private void copyClasses(String name, File projectDir) throws IOException {
-		PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
-		Resource root = resolver.getResource("classpath:org/springframework/boot/build/architecture/" + name);
-		FileSystemUtils.copyRecursively(root.getFile(),
-				new File(projectDir, "classes/org/springframework/boot/build/architecture/" + name));
-
-	}
-
-	private interface Callback<T> {
-
-		void accept(T item) throws Exception;
-
-	}
-
-}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bfpp/nonstatic/NonStaticBeanFactoryPostProcessorConfiguration.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bfpp.nonstatic;
+
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.context.annotation.Bean;
+
+class NonStaticBeanFactoryPostProcessorConfiguration {
+
+	@Bean
+	BeanFactoryPostProcessor nonStaticBeanFactoryPostProcessor() {
+		return (beanFactory) -> {
+		};
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bfpp/noparameters/NoParametersBeanFactoryPostProcessorConfiguration.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bfpp.noparameters;
+
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.context.annotation.Bean;
+
+class NoParametersBeanFactoryPostProcessorConfiguration {
+
+	@Bean
+	static BeanFactoryPostProcessor noParametersBeanFactoryPostProcessor() {
+		return (beanFactory) -> {
+		};
+	}
+
+	@Bean
+	Integer beanOne() {
+		return 1;
+	}
+
+	@Bean
+	String beanTwo() {
+		return "test";
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bfpp/parameters/ParametersBeanFactoryPostProcessorConfiguration.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bfpp.parameters;
+
+import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
+import org.springframework.context.annotation.Bean;
+
+class ParametersBeanFactoryPostProcessorConfiguration {
+
+	@Bean
+	static BeanFactoryPostProcessor parametersBeanFactoryPostProcessor(Integer param) {
+		return (beanFactory) -> {
+		};
+	}
+
+	@Bean
+	Integer beanOne() {
+		return 1;
+	}
+
+	@Bean
+	String beanTwo() {
+		return "test";
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bpp/nonstatic/NonStaticBeanPostProcessorConfiguration.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bpp.nonstatic;
+
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.annotation.Bean;
+
+class NonStaticBeanPostProcessorConfiguration {
+
+	@Bean
+	BeanPostProcessor nonStaticBeanPostProcessor() {
+		return new BeanPostProcessor() {
+
+		};
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bpp/noparameters/NoParametersBeanPostProcessorConfiguration.java

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bpp.noparameters;
+
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.annotation.Bean;
+
+class NoParametersBeanPostProcessorConfiguration {
+
+	@Bean
+	static BeanPostProcessor noParametersBeanPostProcessor() {
+		return new BeanPostProcessor() {
+
+		};
+	}
+
+	@Bean
+	Integer beanOne() {
+		return 1;
+	}
+
+	@Bean
+	String beanTwo() {
+		return "test";
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bpp/safeparameters/SafeParametersBeanPostProcessorConfiguration.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bpp.safeparameters;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Lazy;
+import org.springframework.core.env.Environment;
+
+class SafeParametersBeanPostProcessorConfiguration {
+
+	@Bean
+	static BeanPostProcessor safeParametersBeanPostProcessor(ApplicationContext context, ObjectProvider<String> beanOne,
+			ObjectProvider<String> beanTwo, Environment environment, @Lazy String beanThree) {
+		return new BeanPostProcessor() {
+
+		};
+	}
+
+	@Bean
+	Integer beanOne() {
+		return 1;
+	}
+
+	@Bean
+	String beanTwo() {
+		return "test";
+	}
+
+}

buildSrc/src/test/java/org/springframework/boot/build/architecture/bpp/unsafeparameters/UnsafeParametersBeanPostProcessorConfiguration.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2012-2023 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.boot.build.architecture.bpp.unsafeparameters;
+
+import org.springframework.beans.factory.config.BeanPostProcessor;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.Bean;
+
+class UnsafeParametersBeanPostProcessorConfiguration {
+
+	@Bean
+	static BeanPostProcessor unsafeParametersBeanPostProcessor(ApplicationContext context, Integer beanOne,
+			String beanTwo) {
+		return new BeanPostProcessor() {
+
+		};
+	}
+
+	@Bean
+	Integer beanOne() {
+		return 1;
+	}
+
+	@Bean
+	String beanTwo() {
+		return "test";
+	}
+
+}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpointProxyTests.java

@@ -108,7 +108,7 @@ class ConfigurationPropertiesReportEndpointProxyTests {
 		}
 
 		@Bean
-		MethodValidationPostProcessor testPostProcessor() {
+		static MethodValidationPostProcessor testPostProcessor() {
 			return new MethodValidationPostProcessor();
 		}
 

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/annotation/BaseConfiguration.java

@@ -70,7 +70,7 @@ class BaseConfiguration {
 	}
 
 	@Bean
-	PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
+	static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
 		return new PropertySourcesPlaceholderConfigurer();
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationJedisTests.java

@@ -239,7 +239,7 @@ class RedisAutoConfigurationJedisTests {
 	static class JedisConnectionFactoryCaptorConfiguration {
 
 		@Bean
-		JedisConnectionFactoryCaptor jedisConnectionFactoryCaptor() {
+		static JedisConnectionFactoryCaptor jedisConnectionFactoryCaptor() {
 			return new JedisConnectionFactoryCaptor();
 		}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/validation/ValidationAutoConfigurationTests.java

@@ -368,7 +368,7 @@ class ValidationAutoConfigurationTests {
 	static class SampleConfiguration {
 
 		@Bean
-		MethodValidationPostProcessor testMethodValidationPostProcessor() {
+		static MethodValidationPostProcessor testMethodValidationPostProcessor() {
 			return new MethodValidationPostProcessor();
 		}
 

spring-boot-project/spring-boot-devtools/src/test/java/org/springframework/boot/devtools/autoconfigure/AbstractDevToolsDataSourceAutoConfigurationTests.java

@@ -151,7 +151,7 @@ abstract class AbstractDevToolsDataSourceAutoConfigurationTests {
 	static class DataSourceSpyConfiguration {
 
 		@Bean
-		DataSourceSpyBeanPostProcessor dataSourceSpyBeanPostProcessor() {
+		static DataSourceSpyBeanPostProcessor dataSourceSpyBeanPostProcessor() {
 			return new DataSourceSpyBeanPostProcessor();
 		}
 

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/properties/PropertySourcesDeducerTests.java

@@ -87,7 +87,7 @@ class PropertySourcesDeducerTests {
 	static class PropertySourcesPlaceholderConfigurerConfiguration {
 
 		@Bean
-		PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
+		static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer() {
 			PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();
 			MutablePropertySources propertySources = new MutablePropertySources();
 			propertySources.addFirst(new TestPropertySource());
@@ -106,12 +106,12 @@ class PropertySourcesDeducerTests {
 	static class MultiplePropertySourcesPlaceholderConfigurerConfiguration {
 
 		@Bean
-		PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer1() {
+		static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer1() {
 			return new PropertySourcesPlaceholderConfigurer();
 		}
 
 		@Bean
-		PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer2() {
+		static PropertySourcesPlaceholderConfigurer propertySourcesPlaceholderConfigurer2() {
 			return new PropertySourcesPlaceholderConfigurer();
 		}