Configure auto grow collection limit in DataBinder

Prior to this commit, the `GraphQlArgumentBinder` would use the default
`DataBinder` configuration, including its
`DEFAULT_AUTO_GROW_COLLECTION_LIMIT` which is 256. While this is a
sensible default value for many use cases, GraphQL applications are data
oriented.

This commit configures a larger default for GraphQL applications at
1024. This also provides a way to configure the underlying data binder
before the binding proces starts.

Closes gh-392

spring-graphql/src/main/java/org/springframework/graphql/data/GraphQlArgumentBinder.java

@@ -17,12 +17,14 @@
 package org.springframework.graphql.data;
 
 import java.lang.reflect.Constructor;
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Stack;
+import java.util.function.Consumer;
 
 import graphql.schema.DataFetchingEnvironment;
 
@@ -59,11 +61,18 @@ import org.springframework.validation.FieldError;
  */
 public class GraphQlArgumentBinder {
 
+	/**
+	 * Use a larger {@link DataBinder#DEFAULT_AUTO_GROW_COLLECTION_LIMIT} for GraphQL use cases
+	 */
+	private static final int DEFAULT_AUTO_GROW_COLLECTION_LIMIT = 1024;
+
 	@Nullable
 	private final SimpleTypeConverter typeConverter;
 
 	private final BindingErrorProcessor bindingErrorProcessor = new DefaultBindingErrorProcessor();
 
+	private List<Consumer<DataBinder>> dataBinderInitializers = new ArrayList<>();
+
 
 	public GraphQlArgumentBinder() {
 		this(null);
@@ -90,6 +99,15 @@ public class GraphQlArgumentBinder {
 		return (this.typeConverter != null ? this.typeConverter.getConversionService() : null);
 	}
 
+	/**
+	 * Add a {@link DataBinder} consumer that initializes the binder instance before the binding process.
+	 * @param dataBinderInitializer the data binder initializer
+	 * @since 1.0.1
+	 */
+	public void addDataBinderInitializer(Consumer<DataBinder> dataBinderInitializer) {
+		this.dataBinderInitializers.add(dataBinderInitializer);
+	}
+
 
 	/**
 	 * Bind a single argument, or the full arguments map, onto an object of the
@@ -122,6 +140,7 @@ public class GraphQlArgumentBinder {
 		Assert.notNull(targetClass, "Could not determine target type from " + targetType);
 
 		DataBinder binder = new DataBinder(null, argumentName != null ? argumentName : "arguments");
+		initDataBinder(binder);
 		BindingResult bindingResult = binder.getBindingResult();
 		Stack<String> segments = new Stack<>();
 
@@ -159,6 +178,11 @@ public class GraphQlArgumentBinder {
 		}
 	}
 
+	private void initDataBinder(DataBinder binder) {
+		binder.setAutoGrowCollectionLimit(DEFAULT_AUTO_GROW_COLLECTION_LIMIT);
+		this.dataBinderInitializers.forEach(initializer -> initializer.accept(binder));
+	}
+
 	@Nullable
 	private Object wrapAsOptionalIfNecessary(@Nullable Object value, ResolvableType type) {
 		return (type.resolve(Object.class).equals(Optional.class) ? Optional.ofNullable(value) : value);
@@ -228,6 +252,7 @@ public class GraphQlArgumentBinder {
 		if (ctor.getParameterCount() == 0) {
 			target = BeanUtils.instantiateClass(ctor);
 			DataBinder dataBinder = new DataBinder(target);
+			initDataBinder(dataBinder);
 			dataBinder.getBindingResult().setNestedPath(toArgumentPath(segments));
 			dataBinder.setConversionService(getConversionService());
 			dataBinder.bind(initBindValues(rawMap));

spring-graphql/src/main/java/org/springframework/graphql/data/method/annotation/support/AnnotatedControllerConfigurer.java

@@ -27,6 +27,7 @@ import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.Callable;
 import java.util.concurrent.Executor;
+import java.util.function.Consumer;
 import java.util.stream.Collectors;
 
 import javax.validation.Validator;
@@ -69,6 +70,7 @@ import org.springframework.stereotype.Controller;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
+import org.springframework.validation.DataBinder;
 
 /**
  * {@link RuntimeWiringConfigurer} that detects {@link SchemaMapping @SchemaMapping}
@@ -127,6 +129,9 @@ public class AnnotatedControllerConfigurer
 	@Nullable
 	private HandlerMethodInputValidator validator;
 
+	@Nullable
+	private Consumer<DataBinder> dataBinderInitializer;
+
 
 	/**
 	 * Add a {@code FormatterRegistrar} to customize the {@link ConversionService}
@@ -149,6 +154,15 @@ public class AnnotatedControllerConfigurer
 		this.executor = executor;
 	}
 
+	/**
+	 * Configure an initializer that configures the {@link DataBinder} before the binding process.
+	 * @param dataBinderInitializer the data binder initializer
+	 * @since 1.0.1
+	 */
+	public void setDataBinderInitializer(@Nullable Consumer<DataBinder> dataBinderInitializer) {
+		this.dataBinderInitializer = dataBinderInitializer;
+	}
+
 	@Override
 	public void setApplicationContext(ApplicationContext applicationContext) {
 		this.applicationContext = applicationContext;
@@ -176,6 +190,9 @@ public class AnnotatedControllerConfigurer
 		}
 		resolvers.addResolver(new ArgumentMapMethodArgumentResolver());
 		GraphQlArgumentBinder argumentBinder = new GraphQlArgumentBinder(this.conversionService);
+		if (this.dataBinderInitializer != null) {
+			argumentBinder.addDataBinderInitializer(this.dataBinderInitializer);
+		}
 		resolvers.addResolver(new ArgumentMethodArgumentResolver(argumentBinder));
 		resolvers.addResolver(new ArgumentsMethodArgumentResolver(argumentBinder));
 		resolvers.addResolver(new ContextValueMethodArgumentResolver());

spring-graphql/src/test/java/org/springframework/graphql/data/GraphQlArgumentBinderTests.java

@@ -16,10 +16,14 @@
 
 package org.springframework.graphql.data;
 
+import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
@@ -30,6 +34,8 @@ import org.junit.jupiter.api.Test;
 import org.springframework.core.ResolvableType;
 import org.springframework.graphql.Book;
 import org.springframework.graphql.data.GraphQlArgumentBinder;
+import org.springframework.util.ReflectionUtils;
+import org.springframework.util.StringUtils;
 import org.springframework.validation.BindException;
 import org.springframework.validation.FieldError;
 
@@ -227,6 +233,7 @@ class GraphQlArgumentBinderTests {
 	}
 
 	@Test // gh-410
+	@SuppressWarnings("unchecked")
 	void coercionWithSingletonList() throws Exception {
 
 		Map<String, String> itemMap = new HashMap<>();
@@ -250,6 +257,17 @@ class GraphQlArgumentBinderTests {
 		assertThat(items.get(0).getAge()).isEqualTo(37);
 	}
 
+	@Test // gh-392
+	@SuppressWarnings("unchecked")
+	void shouldHaveHigherDefaultAutoGrowLimit() throws Exception {
+		String items = IntStream.range(0, 260).mapToObj(value -> "{\"name\":\"test\"}").collect(Collectors.joining(","));
+		Object result = this.binder.bind(
+				environment("{\"key\":{\"items\":[" + items + "]}}"), "key",
+				ResolvableType.forClass(ItemListHolder.class));
+		assertThat(result).isNotNull().isInstanceOf(ItemListHolder.class);
+		assertThat(((ItemListHolder) result).getItems()).hasSize(260);
+	}
+
 
 	@SuppressWarnings("unchecked")
 	private DataFetchingEnvironment environment(String jsonPayload) throws JsonProcessingException {