Perform NullAway build-time checks in spring-test

Closes gh-32475

Author: sdeleuze

gradle/spring-module.gradle

@@ -120,8 +120,7 @@ tasks.withType(JavaCompile).configureEach {
         option("NullAway:AnnotatedPackages", "org.springframework")
         option("NullAway:UnannotatedSubPackages", "org.springframework.instrument,org.springframework.context.index," +
 				"org.springframework.asm,org.springframework.cglib,org.springframework.objenesis," +
-				"org.springframework.javapoet,org.springframework.aot.nativex.substitution,org.springframework.aot.nativex.feature," +
-				"org.springframework.test,org.springframework.mock")
+				"org.springframework.javapoet,org.springframework.aot.nativex.substitution,org.springframework.aot.nativex.feature")
     }
 }
 tasks.compileJava {

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

@@ -352,6 +352,7 @@ private GenericApplicationContext loadContextForAotProcessing(
 			}
 			catch (Exception ex) {
 				Throwable cause = (ex instanceof ContextLoadException cle ? cle.getCause() : ex);
+				Assert.state(cause != null, "Cause must not be null");
 				throw new TestContextAotException(
 						"Failed to load ApplicationContext for AOT processing for test class [%s]"
 							.formatted(testClass.getName()), cause);

spring-test/src/main/java/org/springframework/test/context/bean/override/BeanOverrideBeanPostProcessor.java

@@ -179,6 +179,7 @@ else if (enforceExistingDefinition) {
 		registry.registerBeanDefinition(beanName, beanDefinition);
 
 		Object override = overrideMetadata.createOverride(beanName, existingBeanDefinition, null);
+		Assert.state(this.beanFactory != null, "ConfigurableListableBeanFactory must not be null");
 		if (this.beanFactory.isSingleton(beanName)) {
 			// Now we have an instance (the override) that we can register.
 			// At this stage we don't expect a singleton instance to be present,
@@ -222,6 +223,7 @@ protected final Object wrapIfNecessary(Object bean, String beanName) throws Bean
 		final OverrideMetadata metadata = this.earlyOverrideMetadata.get(beanName);
 		if (metadata != null && metadata.getBeanOverrideStrategy() == BeanOverrideStrategy.WRAP_EARLY_BEAN) {
 			bean = metadata.createOverride(beanName, null, bean);
+			Assert.state(this.beanFactory != null, "ConfigurableListableBeanFactory must not be null");
 			metadata.track(bean, this.beanFactory);
 		}
 		return bean;
@@ -234,6 +236,7 @@ private RootBeanDefinition createBeanDefinition(OverrideMetadata metadata) {
 	}
 
 	private Set<String> getExistingBeanNames(ResolvableType resolvableType) {
+		Assert.state(this.beanFactory != null, "ConfigurableListableBeanFactory must not be null");
 		Set<String> beans = new LinkedHashSet<>(
 				Arrays.asList(this.beanFactory.getBeanNamesForType(resolvableType, true, false)));
 		Class<?> type = resolvableType.resolve(Object.class);
@@ -274,6 +277,7 @@ private void inject(Field field, Object target, String beanName) {
 		try {
 			ReflectionUtils.makeAccessible(field);
 			Object existingValue = ReflectionUtils.getField(field, target);
+			Assert.state(this.beanFactory != null, "ConfigurableListableBeanFactory must not be null");
 			Object bean = this.beanFactory.getBean(beanName, field.getType());
 			if (existingValue == bean) {
 				return;
@@ -308,7 +312,7 @@ public static void register(BeanDefinitionRegistry registry, @Nullable Set<Overr
 					constructorArgs.addIndexedArgumentValue(0, new LinkedHashSet<OverrideMetadata>()));
 		ConstructorArgumentValues.ValueHolder constructorArg =
 				definition.getConstructorArgumentValues().getIndexedArgumentValue(0, Set.class);
-		@SuppressWarnings("unchecked")
+		@SuppressWarnings({"unchecked", "NullAway"})
 		Set<OverrideMetadata> existing = (Set<OverrideMetadata>) constructorArg.getValue();
 		if (overrideMetadata != null && existing != null) {
 			existing.addAll(overrideMetadata);

spring-test/src/main/java/org/springframework/test/context/bean/override/BeanOverrideContextCustomizerFactory.java

@@ -21,6 +21,7 @@
 
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ContextConfigurationAttributes;
 import org.springframework.test.context.ContextCustomizer;
 import org.springframework.test.context.ContextCustomizerFactory;
@@ -37,6 +38,7 @@
 public class BeanOverrideContextCustomizerFactory implements ContextCustomizerFactory {
 
 	@Override
+	@Nullable
 	public ContextCustomizer createContextCustomizer(Class<?> testClass,
 			List<ContextConfigurationAttributes> configAttributes) {
 

spring-test/src/main/java/org/springframework/test/context/bean/override/BeanOverrideParser.java

@@ -25,6 +25,7 @@
 
 import org.springframework.beans.BeanUtils;
 import org.springframework.core.ResolvableType;
+import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.annotation.MergedAnnotations;
 import org.springframework.util.Assert;
 import org.springframework.util.ReflectionUtils;
@@ -96,7 +97,9 @@ private void parseField(Field field, Class<?> source) {
 
 			BeanOverride beanOverride = mergedAnnotation.synthesize();
 			BeanOverrideProcessor processor = BeanUtils.instantiateClass(beanOverride.value());
-			Annotation composedAnnotation = mergedAnnotation.getMetaSource().synthesize();
+			MergedAnnotation<?> metaSource = mergedAnnotation.getMetaSource();
+			Assert.state(metaSource != null, "Meta-annotation source must not be null");
+			Annotation composedAnnotation = metaSource.synthesize();
 			ResolvableType typeToOverride = processor.getOrDeduceType(field, composedAnnotation, source);
 
 			Assert.state(overrideAnnotationFound.compareAndSet(false, true),

spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/MockDefinition.java

@@ -75,7 +75,7 @@ public String getBeanOverrideDescription() {
 	}
 
 	@Override
-	protected Object createOverride(String beanName, BeanDefinition existingBeanDefinition, Object existingBeanInstance) {
+	protected Object createOverride(String beanName, @Nullable BeanDefinition existingBeanDefinition, @Nullable Object existingBeanInstance) {
 		return createMock(beanName);
 	}
 

spring-test/src/main/java/org/springframework/test/context/bean/override/mockito/MockitoResetTestExecutionListener.java

@@ -31,6 +31,7 @@
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.core.NativeDetector;
 import org.springframework.core.Ordered;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.TestContext;
 import org.springframework.test.context.support.AbstractTestExecutionListener;
 
@@ -101,6 +102,7 @@ private void resetMocks(ConfigurableApplicationContext applicationContext, MockR
 		}
 	}
 
+	@Nullable
 	private Object getBean(ConfigurableListableBeanFactory beanFactory, String name) {
 		try {
 			if (isStandardBeanOrSingletonFactoryBean(beanFactory, name)) {

spring-test/src/main/java/org/springframework/test/context/jdbc/SqlScriptsTestExecutionListener.java

@@ -412,6 +412,7 @@ private String[] getScripts(Sql sql, Class<?> testClass, @Nullable Method testMe
 	 * Detect a default SQL script by implementing the algorithm defined in
 	 * {@link Sql#scripts}.
 	 */
+	@SuppressWarnings("NullAway")
 	private String detectDefaultScript(Class<?> testClass, @Nullable Method testMethod, boolean classLevel) {
 		Assert.state(classLevel || testMethod != null, "Method-level @Sql requires a testMethod");
 

spring-test/src/main/java/org/springframework/test/context/junit/jupiter/SpringExtension.java

@@ -377,6 +377,7 @@ private static Store getStore(ExtensionContext context) {
 	 * the supplied {@link TestContextManager}.
 	 * @since 6.1
 	 */
+	@SuppressWarnings("NullAway")
 	private static void registerMethodInvoker(TestContextManager testContextManager, ExtensionContext context) {
 		testContextManager.getTestContext().setMethodInvoker(context.getExecutableInvoker()::invoke);
 	}

spring-test/src/main/java/org/springframework/test/context/support/AbstractDirtiesContextTestExecutionListener.java

@@ -84,6 +84,7 @@ protected void dirtyContext(TestContext testContext, @Nullable HierarchyMode hie
 	 * @since 4.2
 	 * @see #dirtyContext
 	 */
+	@SuppressWarnings("NullAway")
 	protected void beforeOrAfterTestMethod(TestContext testContext, MethodMode requiredMethodMode,
 			ClassMode requiredClassMode) throws Exception {
 
@@ -135,6 +136,7 @@ else if (logger.isDebugEnabled()) {
 	 * @since 4.2
 	 * @see #dirtyContext
 	 */
+	@SuppressWarnings("NullAway")
 	protected void beforeOrAfterTestClass(TestContext testContext, ClassMode requiredClassMode) throws Exception {
 		Assert.notNull(testContext, "TestContext must not be null");
 		Assert.notNull(requiredClassMode, "requiredClassMode must not be null");

spring-test/src/main/java/org/springframework/test/context/support/ContextLoaderUtils.java

@@ -232,6 +232,7 @@ static Map<String, List<ContextConfigurationAttributes>> buildContextHierarchyMa
 	 * @throws IllegalArgumentException if the supplied class is {@code null} or if
 	 * {@code @ContextConfiguration} is not <em>present</em> on the supplied class
 	 */
+	@SuppressWarnings("NullAway")
 	static List<ContextConfigurationAttributes> resolveContextConfigurationAttributes(Class<?> testClass) {
 		Assert.notNull(testClass, "Class must not be null");
 

spring-test/src/main/java/org/springframework/test/context/support/TestPropertySourceUtils.java

@@ -135,6 +135,7 @@ else if (!duplicationDetected(currentAttributes, previousAttributes)) {
 		return mergedAttributes;
 	}
 
+	@SuppressWarnings("NullAway")
 	private static boolean duplicationDetected(TestPropertySourceAttributes currentAttributes,
 			@Nullable TestPropertySourceAttributes previousAttributes) {
 

spring-test/src/main/java/org/springframework/test/context/transaction/TransactionalTestExecutionListener.java

@@ -196,6 +196,7 @@ public final int getOrder() {
 	 * @see #getTransactionManager(TestContext, String)
 	 */
 	@Override
+	@SuppressWarnings("NullAway")
 	public void beforeTestMethod(final TestContext testContext) throws Exception {
 		Method testMethod = testContext.getTestMethod();
 		Class<?> testClass = testContext.getTestClass();
@@ -414,6 +415,7 @@ protected PlatformTransactionManager getTransactionManager(TestContext testConte
 	 * @return the <em>default rollback</em> flag for the supplied test context
 	 * @throws Exception if an error occurs while determining the default rollback flag
 	 */
+	@SuppressWarnings("NullAway")
 	protected final boolean isDefaultRollback(TestContext testContext) throws Exception {
 		Class<?> testClass = testContext.getTestClass();
 		Rollback rollback = TestContextAnnotationUtils.findMergedAnnotation(testClass, Rollback.class);

spring-test/src/main/java/org/springframework/test/context/web/WebMergedContextConfiguration.java

@@ -218,8 +218,8 @@ public String getResourceBasePath() {
 	 */
 	@Override
 	public boolean equals(@Nullable Object other) {
-		return (this == other || (super.equals(other) &&
-				this.resourceBasePath.equals(((WebMergedContextConfiguration) other).resourceBasePath)));
+		return (this == other || (super.equals(other) && other instanceof WebMergedContextConfiguration otherConfiguration &&
+				this.resourceBasePath.equals(otherConfiguration.resourceBasePath)));
 	}
 
 	/**

spring-test/src/main/java/org/springframework/test/http/MediaTypeAssert.java

@@ -91,6 +91,7 @@ public MediaTypeAssert isCompatibleWith(String mediaType) {
 	}
 
 
+	@SuppressWarnings("NullAway")
 	private MediaType parseMediaType(String value) {
 		try {
 			return MediaType.parseMediaType(value);

spring-test/src/main/java/org/springframework/test/util/AssertionErrors.java

@@ -16,6 +16,7 @@
 
 package org.springframework.test.util;
 
+import org.springframework.lang.Contract;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ObjectUtils;
 
@@ -33,6 +34,7 @@ public abstract class AssertionErrors {
 	 * Fail a test with the given message.
 	 * @param message a message that describes the reason for the failure
 	 */
+	@Contract("_ -> fail")
 	public static void fail(String message) {
 		throw new AssertionError(message);
 	}
@@ -65,6 +67,7 @@ public static void fail(String message, @Nullable Object expected, @Nullable Obj
 	 * @param message a message that describes the reason for the failure
 	 * @param condition the condition to test for
 	 */
+	@Contract("_, false -> fail")
 	public static void assertTrue(String message, boolean condition) {
 		if (!condition) {
 			fail(message);
@@ -78,6 +81,7 @@ public static void assertTrue(String message, boolean condition) {
 	 * @param condition the condition to test for
 	 * @since 5.2.1
 	 */
+	@Contract("_, true -> fail")
 	public static void assertFalse(String message, boolean condition) {
 		if (condition) {
 			fail(message);
@@ -91,6 +95,7 @@ public static void assertFalse(String message, boolean condition) {
 	 * @param object the object to check
 	 * @since 5.2.1
 	 */
+	@Contract("_, !null -> fail")
 	public static void assertNull(String message, @Nullable Object object) {
 		assertTrue(message, object == null);
 	}
@@ -102,6 +107,7 @@ public static void assertNull(String message, @Nullable Object object) {
 	 * @param object the object to check
 	 * @since 5.1.8
 	 */
+	@Contract("_, null -> fail")
 	public static void assertNotNull(String message, @Nullable Object object) {
 		assertTrue(message, object != null);
 	}

spring-test/src/main/java/org/springframework/test/util/ReflectionTestUtils.java

@@ -172,6 +172,7 @@ public static void setField(
 	 * @see ReflectionUtils#setField(Field, Object, Object)
 	 * @see AopTestUtils#getUltimateTargetObject(Object)
 	 */
+	@SuppressWarnings("NullAway")
 	public static void setField(@Nullable Object targetObject, @Nullable Class<?> targetClass,
 			@Nullable String name, @Nullable Object value, @Nullable Class<?> type) {
 
@@ -259,6 +260,7 @@ public static Object getField(Class<?> targetClass, String name) {
 	 * @see AopTestUtils#getUltimateTargetObject(Object)
 	 */
 	@Nullable
+	@SuppressWarnings("NullAway")
 	public static Object getField(@Nullable Object targetObject, @Nullable Class<?> targetClass, String name) {
 		Assert.isTrue(targetObject != null || targetClass != null,
 			"Either targetObject or targetClass for the field must be specified");

spring-test/src/main/java/org/springframework/test/web/ModelAndViewAssert.java

@@ -53,7 +53,7 @@ public abstract class ModelAndViewAssert {
 	 * @param expectedType expected type of the model value
 	 * @return the model value
 	 */
-	@SuppressWarnings("unchecked")
+	@SuppressWarnings({"unchecked", "NullAway"})
 	public static <T> T assertAndReturnModelAttributeOfType(ModelAndView mav, String modelName, Class<T> expectedType) {
 		Map<String, Object> model = mav.getModel();
 		Object obj = model.get(modelName);
@@ -109,6 +109,7 @@ public static void assertModelAttributeValue(ModelAndView mav, String modelName,
 	 * @param mav the ModelAndView to test against (never {@code null})
 	 * @param expectedModel the expected model
 	 */
+	@SuppressWarnings("NullAway")
 	public static void assertModelAttributeValues(ModelAndView mav, Map<String, Object> expectedModel) {
 		Map<String, Object> model = mav.getModel();
 

spring-test/src/main/java/org/springframework/test/web/UriAssert.java

@@ -80,6 +80,7 @@ public UriAssert matchesAntPattern(String uriPattern) {
 		return this;
 	}
 
+	@SuppressWarnings("NullAway")
 	private String buildUri(String uriTemplate, Object... uriVars) {
 		try {
 			return UriComponentsBuilder.fromUriString(uriTemplate)

spring-test/src/main/java/org/springframework/test/web/client/match/MockRestRequestMatchers.java

@@ -158,6 +158,7 @@ public static RequestMatcher queryParamList(String name, Matcher<? super List<St
 	 * @see #queryParam(String, String...)
 	 */
 	@SafeVarargs
+	@SuppressWarnings("NullAway")
 	public static RequestMatcher queryParam(String name, Matcher<? super String>... matchers) {
 		return request -> {
 			MultiValueMap<String, String> params = getQueryParams(request);
@@ -185,6 +186,7 @@ public static RequestMatcher queryParam(String name, Matcher<? super String>...
 	 * @see #queryParamList(String, Matcher)
 	 * @see #queryParam(String, Matcher...)
 	 */
+	@SuppressWarnings("NullAway")
 	public static RequestMatcher queryParam(String name, String... expectedValues) {
 		return request -> {
 			MultiValueMap<String, String> params = getQueryParams(request);
@@ -362,7 +364,7 @@ private static void assertValueCount(
 		if (values == null) {
 			fail(message + " to exist but was null");
 		}
-		if (count > values.size()) {
+		else if (count > values.size()) {
 			fail(message + " to have at least <" + count + "> values but found " + values);
 		}
 	}

spring-test/src/main/java/org/springframework/test/web/reactive/server/DefaultWebTestClient.java

@@ -374,6 +374,7 @@ public ResponseSpec exchange() {
 					DefaultWebTestClient.this.entityResultConsumer, getResponseTimeout());
 		}
 
+		@SuppressWarnings("NullAway")
 		private ClientRequest.Builder initRequestBuilder() {
 			return ClientRequest.create(this.httpMethod, initUri())
 					.headers(headersToUse -> {

spring-test/src/main/java/org/springframework/test/web/reactive/server/WiretapConnector.java

@@ -62,6 +62,7 @@ class WiretapConnector implements ClientHttpConnector {
 
 
 	@Override
+	@SuppressWarnings("NullAway")
 	public Mono<ClientHttpResponse> connect(HttpMethod method, URI uri,
 			Function<? super ClientHttpRequest, Mono<Void>> requestCallback) {
 
@@ -181,6 +182,7 @@ public Publisher<? extends Publisher<? extends DataBuffer>> getNestedPublisherTo
 			return this.publisherNested;
 		}
 
+		@SuppressWarnings("NullAway")
 		public Mono<byte[]> getContent() {
 			return Mono.defer(() -> {
 				if (this.content.scan(Scannable.Attr.TERMINATED) == Boolean.TRUE) {

spring-test/src/main/java/org/springframework/test/web/servlet/DefaultMvcResult.java

@@ -137,6 +137,7 @@ public Object getAsyncResult() {
 	}
 
 	@Override
+	@SuppressWarnings("NullAway")
 	public Object getAsyncResult(long timeToWait) {
 		if (this.mockRequest.getAsyncContext() != null && timeToWait == -1) {
 			long requestTimeout = this.mockRequest.getAsyncContext().getTimeout();

spring-test/src/main/java/org/springframework/test/web/servlet/assertj/DefaultAssertableMvcResult.java

@@ -68,21 +68,25 @@ public MockHttpServletResponse getResponse() {
 	}
 
 	@Override
+	@Nullable
 	public Object getHandler() {
 		return getTarget().getHandler();
 	}
 
 	@Override
+	@Nullable
 	public HandlerInterceptor[] getInterceptors() {
 		return getTarget().getInterceptors();
 	}
 
 	@Override
+	@Nullable
 	public ModelAndView getModelAndView() {
 		return getTarget().getModelAndView();
 	}
 
 	@Override
+	@Nullable
 	public Exception getResolvedException() {
 		return getTarget().getResolvedException();
 	}

spring-test/src/main/java/org/springframework/test/web/servlet/assertj/MvcResultAssert.java

@@ -203,6 +203,7 @@ public MvcResultAssert hasViewName(String viewName) {
 	}
 
 
+	@SuppressWarnings("NullAway")
 	private ModelAndView getModelAndView() {
 		ModelAndView modelAndView = this.actual.getModelAndView();
 		Assertions.assertThat(modelAndView).as("ModelAndView").isNotNull();