#2 - Singleton Responses incorrectly wrapped in a list

Author: colinfindlay

src/main/java/com/arangodb/graphql/ArangoDataFetcher.java

@@ -89,14 +89,13 @@ private ArangoTraversalQueryResult executeQuery(ArangoTraversalQuery query){
         return result;
     }
 
-    private List<Map> processResult(ArangoTraversalQueryResult result){
+    private Object processResult(ArangoTraversalQueryResult result){
         logger.debug("Converting paths to GraphQL Query Response");
         Instant start = Instant.now();
-        List<Map> convertedResult = result.getResult();
+        Object convertedResult = result.getResult();
         Instant finish = Instant.now();
         long duration = Duration.between(start, finish).toMillis();
         logger.debug("Response conversion completed in {}ms", duration);
-        logger.debug("GraphQL Query Response has {} elements", convertedResult.size());
         return convertedResult;
     }
 

src/main/java/com/arangodb/graphql/query/result/ArangoTraversalQueryResult.java

@@ -23,6 +23,8 @@
 import com.arangodb.graphql.context.ArangoGraphQLContext;
 import com.arangodb.graphql.query.BaseDocumentPathEntity;
 import com.arangodb.graphql.query.result.resolver.ResultResolver;
+import graphql.schema.DataFetchingEnvironment;
+import graphql.schema.GraphQLTypeUtil;
 
 import java.util.List;
 import java.util.Map;
@@ -71,8 +73,18 @@ public int size(){
      *
      * @return The result in the structure requested by the GraphQL Query
      */
-    public List<Map> getResult() {
-        return result;
+    public Object getResult() {
+        DataFetchingEnvironment environment = ctx.getEnvironment();
+        boolean isList = GraphQLTypeUtil.isList(environment.getFieldType());
+        if(isList){
+            return result;
+        }
+        else{
+            if(result.size() == 0){
+                return null;
+            }
+            return result.get(0);
+        }
     }
 
 }

src/test/java/com/arangodb/graphql/query/ArangoTraversalQueryExecutorTest.java

@@ -25,6 +25,8 @@
 import com.arangodb.ArangoDatabase;
 import com.arangodb.graphql.context.ArangoGraphQLContext;
 import com.arangodb.graphql.query.result.ArangoTraversalQueryResult;
+import graphql.schema.DataFetchingEnvironment;
+import graphql.schema.GraphQLOutputType;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -35,6 +37,7 @@
 import java.util.Collections;
 
 import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.nullValue;
 import static org.junit.Assert.*;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.verify;
@@ -58,6 +61,12 @@ public class ArangoTraversalQueryExecutorTest {
     @Mock
     private ArangoGraphQLContext context;
 
+    @Mock
+    private DataFetchingEnvironment dataFetchingEnvironment;
+
+    @Mock
+    private GraphQLOutputType outputType;
+
     private ArangoTraversalQueryExecutor executor;
 
     @Before
@@ -75,13 +84,15 @@ public void execute() {
         when(arango.db("my_db")).thenReturn(database);
         when(database.query(any(), any(), any(), any())).thenReturn(cursor);
         when(cursor.asListRemaining()).thenReturn(Collections.EMPTY_LIST);
+        when(context.getEnvironment()).thenReturn(dataFetchingEnvironment);
+        when(dataFetchingEnvironment.getFieldType()).thenReturn(outputType);
 
         ArgumentCaptor<String> captor = ArgumentCaptor.forClass(String.class);
 
         ArangoTraversalQueryResult result = executor.execute(query);
 
 
-        assertThat(result.getResult().size(), equalTo(0));
+        assertThat(result.getResult(), nullValue());
 
         verify(database).query(captor.capture(), any(), any(), any());
         assertThat(captor.getValue(), equalTo("RETURN 1"));