fix(merge): handle arrays correctly

Author: ardatan

.changeset/lemon-jokes-reflect.md

@@ -0,0 +1,5 @@
+---
+'@graphql-tools/merge': patch
+---
+
+fix(merge): handle arrays correctly

packages/merge/src/typedefs-mergers/merge-typedefs.ts

@@ -122,7 +122,7 @@ function visitTypeSources(
   for (const type of types) {
     if (type) {
       if (Array.isArray(type)) {
-        visitTypeSources(types, allNodes);
+        visitTypeSources(type, allNodes);
       } else if (isSchema(type)) {
         const documentNode = getDocumentNodeFromSchema(type);
         visitTypeSources(documentNode.definitions as DefinitionNode[], allNodes);