🐛 Fix error on data fetching in GraphQL API when a nested field is no…

…n nullable
SoftInstigate · Dec 6, 2023 · 5e36998 · 5e36998
1 parent 1a78276
commit 5e36998
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Showing 4 changed files with 26 additions and 16 deletions.
diff --git a/graphql/src/main/java/org/restheart/graphql/datafetchers/GQLAggregationDataFetcher.java b/graphql/src/main/java/org/restheart/graphql/datafetchers/GQLAggregationDataFetcher.java
@@ -37,7 +37,6 @@
 import com.mongodb.client.AggregateIterable;
 
 import graphql.schema.DataFetchingEnvironment;
-import graphql.schema.GraphQLList;
 
 
 public class GQLAggregationDataFetcher extends GraphQLDataFetcher {
@@ -99,9 +98,7 @@ public Object get(DataFetchingEnvironment env) throws Exception {
             .allowDiskUse(aggregation.getAllowDiskUse().getValue())
             .maxTime(this.aggregationTimeLimit, TimeUnit.MILLISECONDS);
 
-        boolean isMultiple = env.getFieldDefinition().getType() instanceof GraphQLList;
-
-        if (isMultiple) {
+        if (isList(env.getFieldDefinition().getType())) {
             var aggregationResult = new BsonArray();
             res.into(aggregationResult.asArray());
             return aggregationResult;

diff --git a/graphql/src/main/java/org/restheart/graphql/datafetchers/GQLBatchDataFetcher.java b/graphql/src/main/java/org/restheart/graphql/datafetchers/GQLBatchDataFetcher.java
@@ -20,13 +20,13 @@
  */
 package org.restheart.graphql.datafetchers;
 
-import graphql.schema.DataFetchingEnvironment;
-import graphql.schema.GraphQLList;
-import graphql.schema.GraphQLObjectType;
 import org.bson.BsonValue;
 import org.dataloader.DataLoader;
 import org.restheart.graphql.models.QueryMapping;
 
+import graphql.schema.DataFetchingEnvironment;
+import graphql.schema.GraphQLObjectType;
+
 
 public class GQLBatchDataFetcher extends GraphQLDataFetcher{
 
@@ -53,12 +53,10 @@ public Object get(DataFetchingEnvironment env) throws Exception {
 
         return dataLoader.load(int_args, env).thenApply(
             results -> {
-                boolean isMultiple = env.getFieldDefinition().getType() instanceof GraphQLList;
-                if (isMultiple){
+                if (isList(env.getFieldDefinition().getType())) {
                     return results;
-                }
-                else{
-                    return results.asArray().size() > 0 ? results.asArray().get(0) : null;
+                } else {
+                    return !results.asArray().isEmpty() ? results.asArray().get(0) : null;
                 }
             }
         );

diff --git a/graphql/src/main/java/org/restheart/graphql/datafetchers/GQLQueryDataFetcher.java b/graphql/src/main/java/org/restheart/graphql/datafetchers/GQLQueryDataFetcher.java
@@ -29,7 +29,6 @@
 import org.slf4j.LoggerFactory;
 
 import graphql.schema.DataFetchingEnvironment;
-import graphql.schema.GraphQLList;
 
 public class GQLQueryDataFetcher extends GraphQLDataFetcher {
     private static final Logger LOGGER = LoggerFactory.getLogger(GQLQueryDataFetcher.class);
@@ -76,9 +75,7 @@ public Object get(DataFetchingEnvironment env) throws Exception {
             query = query.limit(_limit);
         }
 
-        boolean isMultiple = env.getFieldDefinition().getType() instanceof GraphQLList;
-
-        if (isMultiple) {
+        if (isList(env.getFieldDefinition().getType())) {
             var queryResult = new BsonArray();
             query.into(queryResult.asArray());
             return queryResult;

diff --git a/graphql/src/main/java/org/restheart/graphql/datafetchers/GraphQLDataFetcher.java b/graphql/src/main/java/org/restheart/graphql/datafetchers/GraphQLDataFetcher.java
@@ -27,6 +27,9 @@
 
 import graphql.schema.DataFetcher;
 import graphql.schema.DataFetchingEnvironment;
+import graphql.schema.GraphQLList;
+import graphql.schema.GraphQLNonNull;
+import graphql.schema.GraphQLType;
 
 public abstract class GraphQLDataFetcher implements DataFetcher<Object> {
     protected static MongoClient mongoClient;
@@ -52,4 +55,19 @@ protected void storeRootDoc(DataFetchingEnvironment env) {
             ctx.put("rootDoc", env.getSource());
         }
     }
+
+    /**
+     * check if type is a list also when the actual type is wrapped in GraphQLNonNull
+     * @param type
+     * @return true if the field type is a list
+     */
+    protected boolean isList(GraphQLType type) {
+        if (type instanceof GraphQLList) {
+            return true;
+        } else if (type instanceof GraphQLNonNull nnt) {
+            return isList(nnt.getWrappedType());
+        }
+
+        return false;
+    }
 }