Flatten nested argument maps in QuerydslDataFetcher

We now flatten argument maps to ensure keys in the resulting
parameter map are fully-qualified property paths.

Previously, we built a parameter map containing nested maps
leading to invalid queries.

Closes gh-1085

spring-graphql/src/main/java/org/springframework/graphql/data/query/QuerydslDataFetcher.java

@@ -142,7 +142,6 @@ public abstract class QuerydslDataFetcher<T> {
 	 * @param environment contextual info for the GraphQL request
 	 * @return the resulting predicate
 	 */
-	@SuppressWarnings({"unchecked"})
 	protected Predicate buildPredicate(DataFetchingEnvironment environment) {
 		MultiValueMap<String, Object> parameters = new LinkedMultiValueMap<>();
 		QuerydslBindings bindings = new QuerydslBindings();
@@ -150,15 +149,29 @@ public abstract class QuerydslDataFetcher<T> {
 		EntityPath<?> path = SimpleEntityPathResolver.INSTANCE.createPath(this.domainType.getType());
 		this.customizer.customize(bindings, path);
 
-		for (Map.Entry<String, Object> entry : getArgumentValues(environment).entrySet()) {
-			Object value = entry.getValue();
-			List<Object> values = (value instanceof List) ? (List<Object>) value : Collections.singletonList(value);
-			parameters.put(entry.getKey(), values);
-		}
+		parameters.putAll(flatten(null, getArgumentValues(environment)));
 
 		return BUILDER.getPredicate(this.domainType, parameters, bindings);
 	}
 
+	@SuppressWarnings("unchecked")
+	private MultiValueMap<String, Object> flatten(@Nullable String prefix, Map<String, Object> inputParameters) {
+		MultiValueMap<String, Object> parameters = new LinkedMultiValueMap<>();
+
+		for (Map.Entry<String, Object> entry : inputParameters.entrySet()) {
+			Object value = entry.getValue();
+			if (value instanceof Map<?, ?> nested) {
+				parameters.addAll(flatten(entry.getKey(), (Map<String, Object>) nested));
+			}
+			else {
+				List<Object> values = (value instanceof List) ? (List<Object>) value : Collections.singletonList(value);
+				parameters.put(((prefix != null) ? prefix + "." : "") + entry.getKey(), values);
+			}
+		}
+
+		return parameters;
+	}
+
 	/**
 	 * For a single argument that is a GraphQL input type, return the sub-map
 	 * under the argument name, or otherwise the top-level argument map.

spring-graphql/src/test/java/org/springframework/graphql/QAuthor.java

@@ -0,0 +1,49 @@
+/*
+ * Copyright 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.
+ * 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.graphql;
+
+import com.querydsl.core.types.Path;
+import com.querydsl.core.types.PathMetadata;
+import com.querydsl.core.types.dsl.EntityPathBase;
+import com.querydsl.core.types.dsl.NumberPath;
+import com.querydsl.core.types.dsl.StringPath;
+
+import static com.querydsl.core.types.PathMetadataFactory.forVariable;
+
+/**
+ * QAuthor is a Querydsl query type for Author
+ */
+public class QAuthor extends EntityPathBase<Author> {
+	private static final long serialVersionUID = 1773522017L;
+	public static final QAuthor author = new QAuthor("author");
+	public final StringPath firstName = createString("firstName");
+	public final NumberPath<Long> id = createNumber("id", Long.class);
+	public final StringPath lastName = createString("lastName");
+
+	public QAuthor(String variable) {
+		super(Author.class, forVariable(variable));
+	}
+
+	public QAuthor(Path<? extends Author> path) {
+		super(path.getType(), path.getMetadata());
+	}
+
+	public QAuthor(PathMetadata metadata) {
+		super(Author.class, metadata);
+	}
+
+}

spring-graphql/src/test/java/org/springframework/graphql/data/query/QBook.java

@@ -18,30 +18,43 @@ package org.springframework.graphql.data.query;
 
 import com.querydsl.core.types.Path;
 import com.querydsl.core.types.PathMetadata;
-import com.querydsl.core.types.PathMetadataFactory;
 import com.querydsl.core.types.dsl.EntityPathBase;
 import com.querydsl.core.types.dsl.NumberPath;
+import com.querydsl.core.types.dsl.PathInits;
 import com.querydsl.core.types.dsl.StringPath;
 
+import static com.querydsl.core.types.PathMetadataFactory.forVariable;
+
 /**
- * Generated by Querydsl.
+ * QBook is a Querydsl query type for Book
  */
 public class QBook extends EntityPathBase<Book> {
 	private static final long serialVersionUID = 1773522017L;
+	private static final PathInits INITS = PathInits.DIRECT2;
 	public static final QBook book = new QBook("book");
-	public final StringPath author = this.createString("author");
-	public final NumberPath<Long> id = this.createNumber("id", Long.class);
-	public final StringPath name = this.createString("name");
+	public final org.springframework.graphql.QAuthor author;
+	public final NumberPath<Long> id = createNumber("id", Long.class);
+	public final StringPath name = createString("name");
 
 	public QBook(String variable) {
-		super(Book.class, PathMetadataFactory.forVariable(variable));
+		this(Book.class, forVariable(variable), INITS);
 	}
 
 	public QBook(Path<? extends Book> path) {
-		super(path.getType(), path.getMetadata());
+		this(path.getType(), path.getMetadata(), PathInits.getFor(path.getMetadata(), INITS));
 	}
 
 	public QBook(PathMetadata metadata) {
-		super(Book.class, metadata);
+		this(metadata, PathInits.getFor(metadata, INITS));
 	}
+
+	public QBook(PathMetadata metadata, PathInits inits) {
+		this(Book.class, metadata, inits);
+	}
+
+	public QBook(Class<? extends Book> type, PathMetadata metadata, PathInits inits) {
+		super(type, metadata, inits);
+		this.author = inits.isInitialized("author") ? new org.springframework.graphql.QAuthor(forProperty("author")) : null;
+	}
+
 }

spring-graphql/src/test/java/org/springframework/graphql/data/query/QuerydslDataFetcherTests.java

@@ -215,14 +215,14 @@ class QuerydslDataFetcherTests {
 				.many();
 
 		graphQlSetup("books", fetcher).toWebGraphQlHandler()
-				.handleRequest(request("{ books(name: \"H\", author: \"Doug\") {name}}"))
+				.handleRequest(request("{ books(name: \"H\") {name}}"))
 				.block();
 
 		ArgumentCaptor<Predicate> predicateCaptor = ArgumentCaptor.forClass(Predicate.class);
 		verify(mockRepository).findBy(predicateCaptor.capture(), any());
 
 		Predicate predicate = predicateCaptor.getValue();
-		assertThat(predicate).isEqualTo(QBook.book.name.startsWith("H").and(QBook.book.author.eq("Doug")));
+		assertThat(predicate).isEqualTo(QBook.book.name.startsWith("H"));
 	}
 
 	@Test
@@ -346,6 +346,25 @@ class QuerydslDataFetcherTests {
 		assertThat(books.get(0).getName()).isEqualTo(book1.getName());
 	}
 
+	@Test
+	void shouldConsiderNestedArguments() {
+		Book book1 = new Book(42L, "Hitchhiker's Guide to the Galaxy", new Author(0L, "Douglas", "Adams"));
+		Book book2 = new Book(53L, "Breaking Bad", new Author(0L, "", "Heisenberg"));
+		mockRepository.saveAll(Arrays.asList(book1, book2));
+
+		String queryName = "booksByNestableCriteria";
+
+		Mono<ExecutionGraphQlResponse> responseMono =
+				graphQlSetup(queryName, QuerydslDataFetcher.builder(mockRepository).many())
+						.toGraphQlService()
+						.execute(request("{" + queryName + "(author: {firstName: \"Douglas\"}) {name}}"));
+
+		List<Book> books = ResponseHelper.forResponse(responseMono).toList(queryName, Book.class);
+
+		assertThat(books).hasSize(1);
+		assertThat(books.get(0).getName()).isEqualTo(book1.getName());
+	}
+
 	private static GraphQlSetup graphQlSetup(String fieldName, DataFetcher<?> fetcher) {
 		return GraphQlSetup.schemaResource(BookSource.schema).queryFetcher(fieldName, fetcher);
 	}

spring-graphql/src/test/resources/books/schema.graphqls

@@ -2,6 +2,7 @@ type Query {
     bookById(id: ID): Book
     booksById(id: [ID]): [Book]
     books(id: ID, name: String, author: String): [Book!]!
+    booksByNestableCriteria(id: ID, name: String, author: AuthorCriteria): [Book!]!
     booksByCriteria(criteria:BookCriteria): [Book]
     booksByProjectedArguments(name: String, author: String): [Book]
     booksByProjectedCriteria(criteria:BookCriteria): [Book]
@@ -21,6 +22,12 @@ input BookCriteria {
     author: String
 }
 
+input AuthorCriteria {
+    id: ID
+    firstName: String
+    lastName: String
+}
+
 type Book {
     id: ID
     name: String