Polishing in data binding tests

See gh-32676

spring-web/src/main/java/org/springframework/web/bind/support/WebExchangeDataBinder.java

@@ -148,13 +148,19 @@ public class WebExchangeDataBinder extends WebDataBinder {
 
 	protected static void addBindValue(Map<String, Object> params, String key, List<?> values) {
 		if (!CollectionUtils.isEmpty(values)) {
-			values = values.stream()
-					.map(value -> value instanceof FormFieldPart formFieldPart ? formFieldPart.value() : value)
-					.toList();
-			params.put(key, values.size() == 1 ? values.get(0) : values);
+			if (values.size() == 1) {
+				params.put(key, adaptBindValue(values.get(0)));
+			}
+			else {
+				params.put(key, values.stream().map(WebExchangeDataBinder::adaptBindValue).toList());
+			}
 		}
 	}
 
+	private static Object adaptBindValue(Object value) {
+		return (value instanceof FormFieldPart part ? part.value() : value);
+	}
+
 
 	/**
 	 * Resolve values from a map.

spring-webflux/src/test/java/org/springframework/web/reactive/BindingContextTests.java

@@ -16,10 +16,11 @@
 
 package org.springframework.web.reactive;
 
+import java.lang.reflect.Method;
+
 import jakarta.validation.Valid;
 import org.junit.jupiter.api.Test;
 
-import org.springframework.core.MethodParameter;
 import org.springframework.core.ResolvableType;
 import org.springframework.validation.Errors;
 import org.springframework.validation.SmartValidator;
@@ -27,7 +28,6 @@ import org.springframework.validation.Validator;
 import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.web.bind.WebDataBinder;
 import org.springframework.web.testfixture.http.server.reactive.MockServerHttpRequest;
-import org.springframework.web.testfixture.method.ResolvableMethod;
 import org.springframework.web.testfixture.server.MockServerWebExchange;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -40,44 +40,37 @@ import static org.mockito.BDDMockito.when;
 class BindingContextTests {
 
 	@Test
-	void jakartaValidatorExcludedWhenMethodValidationApplicable() {
+	void jakartaValidatorExcludedWhenMethodValidationApplicable() throws Exception {
 		BindingContext bindingContext = new BindingContext(null);
 		bindingContext.setMethodValidationApplicable(true);
 
-		MethodParameter parameter = ResolvableMethod.on(BindingContextTests.class)
-				.named("handle").build().annotPresent(Valid.class).arg();
+		Method method = getClass().getDeclaredMethod("handleValidObject", Foo.class);
+		ResolvableType targetType = ResolvableType.forMethodParameter(method, 0);
 
-		WebDataBinder dataBinder = bindingContext.createDataBinder(
-				MockServerWebExchange.from(MockServerHttpRequest.get("")), new Foo(), "foo",
-				ResolvableType.forMethodParameter(parameter));
+		WebDataBinder binder = bindingContext.createDataBinder(
+				MockServerWebExchange.from(MockServerHttpRequest.get("")), new Foo(), "foo", targetType);
 
 		Validator springValidator = mock(Validator.class);
 		when(springValidator.supports(Foo.class)).thenReturn(true);
-		dataBinder.addValidators(springValidator);
+		binder.addValidators(springValidator);
 
 		LocalValidatorFactoryBean beanValidator = new LocalValidatorFactoryBean();
 		beanValidator.afterPropertiesSet();
-		dataBinder.addValidators(beanValidator);
+		binder.addValidators(beanValidator);
 
 		WrappedBeanValidator wrappedBeanValidator = new WrappedBeanValidator(beanValidator);
-		dataBinder.addValidators(wrappedBeanValidator);
+		binder.addValidators(wrappedBeanValidator);
 
-		assertThat(dataBinder.getValidatorsToApply()).containsExactly(springValidator);
+		assertThat(binder.getValidatorsToApply()).containsExactly(springValidator);
 	}
 
 
 	@SuppressWarnings("unused")
-	private void handle(@Valid Foo foo) {
+	private void handleValidObject(@Valid Foo foo) {
 	}
 
 
-	private static class WrappedBeanValidator implements SmartValidator {
-
-		private final jakarta.validation.Validator validator;
-
-		private WrappedBeanValidator(jakarta.validation.Validator validator) {
-			this.validator = validator;
-		}
+	private record WrappedBeanValidator(jakarta.validation.Validator validator) implements SmartValidator {
 
 		@Override
 		public boolean supports(Class<?> clazz) {
@@ -100,6 +93,6 @@ class BindingContextTests {
 	}
 
 
-	private static class Foo {}
+	private static final class Foo {}
 
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ExtendedServletRequestDataBinder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2023 the original author or authors.
+ * Copyright 2002-2024 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.
@@ -81,24 +81,29 @@ public class ExtendedServletRequestDataBinder extends ServletRequestDataBinder {
 	protected void addBindValues(MutablePropertyValues mpvs, ServletRequest request) {
 		Map<String, String> uriVars = getUriVars(request);
 		if (uriVars != null) {
-			uriVars.forEach((name, value) -> {
-				if (mpvs.contains(name)) {
-					if (logger.isDebugEnabled()) {
-						logger.debug("URI variable '" + name + "' overridden by request bind value.");
-					}
-				}
-				else {
-					mpvs.addPropertyValue(name, value);
-				}
-			});
+			uriVars.forEach((name, value) -> addValueIfNotPresent(mpvs, "URI variable", name, value));
 		}
 	}
 
 	@SuppressWarnings("unchecked")
 	@Nullable
 	private static Map<String, String> getUriVars(ServletRequest request) {
-		String attr = HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE;
-		return (Map<String, String>) request.getAttribute(attr);
+		return (Map<String, String>) request.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE);
+	}
+
+	private static void addValueIfNotPresent(
+			MutablePropertyValues mpvs, String label, String name, @Nullable Object value) {
+
+		if (value != null) {
+			if (mpvs.contains(name)) {
+				if (logger.isDebugEnabled()) {
+					logger.debug(label + " '" + name + "' overridden by request bind value.");
+				}
+			}
+			else {
+				mpvs.addPropertyValue(name, value);
+			}
+		}
 	}
 
 

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/ExtendedServletRequestDataBinderTests.java

@@ -45,10 +45,10 @@ class ExtendedServletRequestDataBinderTests {
 
 	@Test
 	void createBinder() {
-		Map<String, String> uriTemplateVars = new HashMap<>();
-		uriTemplateVars.put("name", "nameValue");
-		uriTemplateVars.put("age", "25");
-		request.setAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE, uriTemplateVars);
+
+		this.request.setAttribute(
+				HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE,
+				Map.of("name", "nameValue", "age", "25"));
 
 		TestBean target = new TestBean();
 		ServletRequestDataBinder binder = new ExtendedServletRequestDataBinder(target, "");