From b0eb3f23214de9be1ce612f0ece2cd75d8e2fdc4 Mon Sep 17 00:00:00 2001
From: Roman Lovakov <rlovakov@nota.tech>
Date: Fri, 13 Sep 2024 20:44:02 +0300
Subject: [PATCH] Fix ConcurrentModificationException in federation fetcher

---
 .../io/smallrye/graphql/bootstrap/FederationDataFetcher.java   | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/server/implementation/src/main/java/io/smallrye/graphql/bootstrap/FederationDataFetcher.java b/server/implementation/src/main/java/io/smallrye/graphql/bootstrap/FederationDataFetcher.java
index 43d14724a..312a90285 100644
--- a/server/implementation/src/main/java/io/smallrye/graphql/bootstrap/FederationDataFetcher.java
+++ b/server/implementation/src/main/java/io/smallrye/graphql/bootstrap/FederationDataFetcher.java
@@ -11,6 +11,7 @@
 import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentHashMap;
 import java.util.function.BiFunction;
 import java.util.function.Function;
 import java.util.stream.Collectors;
@@ -39,7 +40,7 @@ public class FederationDataFetcher implements DataFetcher<CompletableFuture<List
     public static final String TYPENAME = "__typename";
     private final GraphQLObjectType queryType;
     private final GraphQLCodeRegistry codeRegistry;
-    private final HashMap<TypeAndArgumentNames, TypeFieldWrapper> cache = new HashMap<>();
+    private final ConcurrentHashMap<TypeAndArgumentNames, TypeFieldWrapper> cache = new ConcurrentHashMap<>();
 
     public FederationDataFetcher(GraphQLObjectType queryType, GraphQLCodeRegistry codeRegistry) {
         this.queryType = queryType;