Add test

Author: JoviDeCroock

src/validation/__tests__/VariablesInAllowedPositionRule-test.ts

@@ -370,6 +370,16 @@ describe('Validates OneOf Input Objects', () => {
     `);
   });
 
+  it('Undefined variable in oneOf input object', () => {
+    expectErrors(`
+      {
+        complicatedArgs {
+          oneOfArgField(oneOfArg: { stringField: $undefinedVariable })
+        }
+      }
+    `).toDeepEqual([]);
+  });
+
   it('Forbids one nullable variable', () => {
     expectErrors(`
       query ($string: String) {

src/validation/rules/ValuesOfCorrectTypeRule.ts

@@ -82,12 +82,7 @@ export function ValuesOfCorrectTypeRule(
       }
 
       if (type.isOneOf) {
-        validateOneOfInputObject(
-          context,
-          node,
-          type,
-          fieldNodeMap,
-        );
+        validateOneOfInputObject(context, node, type, fieldNodeMap);
       }
     },
     ObjectField(node) {