Fixed Hibernate NPE and cannot load multiple bags in one query exception

This closes #1, closes #2

Author: igdianov

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

@@ -215,17 +215,37 @@ public void queryDeepNesting() {
 
 
         String expected = "{Droid={name=R2-D2, friends=["
-            + "{name=Luke Skywalker, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=Han Solo}, {name=Leia Organa}, {name=C-3PO}, {name=R2-D2}]}, "
-            + "{name=Han Solo, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=Luke Skywalker}, {name=Leia Organa}, {name=R2-D2}]}, "
-            + "{name=Leia Organa, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=Luke Skywalker}, {name=Han Solo}, {name=C-3PO}, {name=R2-D2}]}"
+            + "{name=Leia Organa, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=C-3PO}, {name=R2-D2}, {name=Han Solo}, {name=Luke Skywalker}]}, "
+            + "{name=Han Solo, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=Leia Organa}, {name=R2-D2}, {name=Luke Skywalker}]}, "
+            + "{name=Luke Skywalker, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=C-3PO}, {name=Leia Organa}, {name=R2-D2}, {name=Han Solo}]}"
             + "]}}";
+        
+        //when:
+        Object result = executor.execute(query).getData();
 
+        //then:
+        assertThat(result.toString()).isEqualTo(expected);
+    }
+    
+    // Cannot simultaneously fetch multiple bags #2
+    @Test
+    public void queryDeepNestingPlural() {
+        //given:
+        String query = "query { Droids(where: {id: {EQ: \"2001\"}}) { select { name, friends { name, appearsIn, friends { name } } }  }}";
+
+        String expected = "{Droids={select=[{name=R2-D2, friends=["
+            + "{name=Leia Organa, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=C-3PO}, {name=R2-D2}, {name=Han Solo}, {name=Luke Skywalker}]}, "
+            + "{name=Han Solo, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=R2-D2}, {name=Leia Organa}, {name=Luke Skywalker}]}, "
+            + "{name=Luke Skywalker, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS], friends=[{name=C-3PO}, {name=R2-D2}, {name=Leia Organa}, {name=Han Solo}]}]}"
+            + "]}}";
+        
         //when:
         Object result = executor.execute(query).getData();
 
         //then:
         assertThat(result.toString()).isEqualTo(expected);
     }
+        
 
     @Test
     public void queryWhereRoot() {
@@ -280,11 +300,12 @@ public void queryByCollectionOfEnumsAtRootLevel() {
         //given:
         String query = "query { Humans ( where: { appearsIn: {IN: [THE_FORCE_AWAKENS]}}) { select { name appearsIn } } }";
 
+        
         String expected = "{Humans={select=["
-            + "{name=Luke Skywalker, appearsIn=[EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS, A_NEW_HOPE]}, "
+            + "{name=Luke Skywalker, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS]}, "
             + "{name=Han Solo, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS]}, "
-            + "{name=Leia Organa, appearsIn=[RETURN_OF_THE_JEDI, EMPIRE_STRIKES_BACK, A_NEW_HOPE, THE_FORCE_AWAKENS]}"
-            + "]}}";
+            + "{name=Leia Organa, appearsIn=[A_NEW_HOPE, EMPIRE_STRIKES_BACK, RETURN_OF_THE_JEDI, THE_FORCE_AWAKENS]}"
+            + "]}}";      
 
         //when:
         Object result = executor.execute(query).getData();

graphql-jpa-query-schema/src/test/java/com/introproventures/graphql/jpa/query/schema/model/starwars/Character.java

@@ -16,7 +16,7 @@
 
 package com.introproventures.graphql.jpa.query.schema.model.starwars;
 
-import java.util.Collection;
+import java.util.Set;
 
 import javax.persistence.ElementCollection;
 import javax.persistence.Entity;
@@ -26,14 +26,21 @@
 import javax.persistence.JoinColumn;
 import javax.persistence.JoinTable;
 import javax.persistence.ManyToMany;
+import javax.persistence.OrderBy;
 
 import com.introproventures.graphql.jpa.query.annotation.GraphQLDescription;
 
-import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
 
 @Entity
 @GraphQLDescription("Abstract representation of an entity in the Star Wars Universe")
-@Data
+@Getter
+@Setter
+@ToString
+@EqualsAndHashCode(exclude={"appearsIn","friends"}) // Fixes NPE in Hibernate when initializing loaded collections #1
 public abstract class Character {
 
     @Id
@@ -48,11 +55,14 @@ public abstract class Character {
     @JoinTable(name="character_friends",
             joinColumns=@JoinColumn(name="source_id", referencedColumnName="id"),
             inverseJoinColumns=@JoinColumn(name="friend_id", referencedColumnName="id"))
-    Collection<Character> friends;
+    Set<Character> friends; 
 
     @GraphQLDescription("What Star Wars episodes does this character appear in")
     @ElementCollection(targetClass = Episode.class)
     @Enumerated(EnumType.ORDINAL)
-    Collection<Episode> appearsIn;
+    @OrderBy
+    Set<Episode> appearsIn;
+    
+    Character() {}
 
 }