fix(GH-38): Support JPA @ElementCollection annotation with @embeddable generic type (#270)

Author: igdianov

graphql-jpa-query-example-model-books/src/main/java/com/introproventures/graphql/jpa/query/schema/model/book/Book.java

@@ -39,7 +39,7 @@
 
 @Data
 @Entity
-@EqualsAndHashCode(exclude= {"author", "tags"})
+@EqualsAndHashCode(exclude= {"author", "tags", "publishers"})
 public class Book {
 	@Id
 	Long id;
@@ -64,6 +64,9 @@ public class Book {
 	Genre genre;
 
     Date publicationDate;
+    
+    @ElementCollection(fetch = FetchType.LAZY)
+    Set<Publisher> publishers;
 
     @Transient
 	@GraphQLIgnore

graphql-jpa-query-example-model-books/src/main/java/com/introproventures/graphql/jpa/query/schema/model/book/Publisher.java

@@ -0,0 +1,13 @@
+package com.introproventures.graphql.jpa.query.schema.model.book;
+
+import javax.persistence.Embeddable;
+
+import lombok.Data;
+
+@Data
+@Embeddable
+public class Publisher {
+    private String name;
+
+    private String country;
+}

graphql-jpa-query-example-relay/src/main/resources/data.sql

@@ -24,3 +24,7 @@ insert into author_phone_numbers(phone_number, author_id) values
 	('1-123-5678', 1),
 	('4-123-1234', 4),
 	('4-123-5678', 4);
+
+insert into book_publishers(book_id, name, country) values
+	(3, 'Independent', 'UK'), (3, 'Amazon', 'US'),
+	(2, 'Willey', 'US'), (2, 'Simon', 'EU');

graphql-jpa-query-schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/GraphQLJpaQueryFactory.java

@@ -866,6 +866,7 @@ protected Predicate getObjectFieldPredicate(DataFetchingEnvironment environment,
         if(isEntityType(environment)) {
             Attribute<?,?> attribute = getAttribute(environment, argument.getName());
 
+            // TODO add support for embedded element collection, i.e. attribute.isCollection()
             if(attribute.isAssociation()) {
                 GraphQLFieldDefinition fieldDefinition = getFieldDefinition(environment.getGraphQLSchema(),
                                                                      this.getObjectType(environment),

graphql-jpa-query-schema/src/main/java/com/introproventures/graphql/jpa/query/schema/impl/GraphQLJpaSchemaBuilder.java

@@ -58,6 +58,7 @@
 import com.introproventures.graphql.jpa.query.schema.impl.EntityIntrospector.EntityIntrospectionResult.AttributePropertyDescriptor;
 import com.introproventures.graphql.jpa.query.schema.impl.PredicateFilter.Criteria;
 import com.introproventures.graphql.jpa.query.schema.relay.GraphQLJpaRelayDataFetcher;
+
 import graphql.Assert;
 import graphql.Directives;
 import graphql.Scalars;
@@ -418,6 +419,14 @@ private GraphQLArgument computeWhereArgument(ManagedType<?> managedType) {
                                                .map(this::getInputObjectField)
                                                .collect(Collectors.toList())
             )
+            // TODO support embedded element collections
+//            .fields(managedType.getAttributes().stream()
+//                                               .filter(Attribute::isCollection)
+//                                               .filter(this::isNotIgnored)
+//                                               .filter(this::isNotIgnoredFilter)
+//                                               .map(this::getInputObjectField)
+//                                               .collect(Collectors.toList())
+//            )
             .build();
 
         return GraphQLArgument.newArgument()
@@ -1047,6 +1056,13 @@ else if (isElementCollection(attribute)) {
 
             	return input ? graphQLType : new GraphQLList(graphQLType);
             }
+            else if (foreignType.getPersistenceType() == Type.PersistenceType.EMBEDDABLE) {
+                EmbeddableType embeddableType = EmbeddableType.class.cast(foreignType);
+                GraphQLType graphQLType = getEmbeddableType(embeddableType, 
+                                                            input);
+                
+                return input ?  graphQLType : new GraphQLList(graphQLType);
+            }
         }
 
         final String declaringType = attribute.getDeclaringType().getJavaType().getName(); // fully qualified name of the entity class

graphql-jpa-query-schema/src/test/java/com/introproventures/graphql/jpa/query/schema/GraphQLExecutorTests.java

@@ -42,6 +42,7 @@
 import com.introproventures.graphql.jpa.query.AbstractSpringBootTestSupport;
 import com.introproventures.graphql.jpa.query.schema.impl.GraphQLJpaExecutor;
 import com.introproventures.graphql.jpa.query.schema.impl.GraphQLJpaSchemaBuilder;
+
 import graphql.ErrorType;
 import graphql.ExecutionResult;
 import graphql.GraphQLError;
@@ -662,6 +663,30 @@ public void queryForEntityWithEmbeddedFieldWithWhere() {
         // then
         assertThat(result.toString()).isEqualTo(expected);
     }
+    
+    @Test
+    public void queryForEntityWithEmbeddableElementCollection() {
+        //given
+        String query = "{ Books(where: { author: {name: {LIKE: \"Leo\"}}}) { select { id title publishers { name country } } } }";
+
+        String expected = "{Books={select=["
+                + "{id=2, title=War and Peace, publishers=["
+                +   "{name=Willey, country=US}, "
+                +   "{name=Simon, country=EU}"
+                + "]}, "
+                + "{id=3, title=Anna Karenina, publishers=["
+                +   "{name=Independent, country=UK}, "
+                +   "{name=Amazon, country=US}"
+                + "]}"
+                + "]}}";
+
+        //when
+        Object result = executor.execute(query).getData();
+
+        // then
+        assertThat(result.toString()).isEqualTo(expected);
+    }
+    
 
     @Test
     public void queryWithNumericBetweenPredicate() {

graphql-jpa-query-schema/src/test/resources/data.sql

@@ -137,6 +137,10 @@ insert into author_phone_numbers(phone_number, author_id) values
 	('1-123-5678', 1),
 	('4-123-1234', 4),
 	('4-123-5678', 4);
+
+insert into book_publishers(book_id, name, country) values
+	(3, 'Independent', 'UK'), (3, 'Amazon', 'US'),
+	(2, 'Willey', 'US'), (2, 'Simon', 'EU');
 
 -- Car
 insert into Car (id, brand, identification) values