fix(JSONObject): Throw proper error if literal is not an object

.changeset/hip-games-glow.md

@@ -0,0 +1,5 @@
+---
+'graphql-scalars': patch
+---
+
+fix(JSONObject): Throw proper error if literal is not an object

src/scalars/json/utils.ts

@@ -1,4 +1,4 @@
-import { Kind, ValueNode, ObjectValueNode } from 'graphql';
+import { Kind, print, ValueNode } from 'graphql';
 import { createGraphQLError } from '../../error.js';
 
 export function identity<T>(value: T): T {
@@ -21,7 +21,18 @@ export function ensureObject(value: any, ast?: ValueNode): object {
   return value;
 }
 
-export function parseObject(ast: ObjectValueNode, variables: any): any {
+export function parseObject(ast: ValueNode, variables: any): any {
+  if (ast.kind !== Kind.OBJECT) {
+    throw createGraphQLError(
+      `JSONObject cannot represent non-object value: ${print(ast)}`,
+      ast
+        ? {
+            nodes: ast,
+          }
+        : undefined,
+    );
+  }
+
   const value = Object.create(null);
   ast.fields.forEach(field => {
     // eslint-disable-next-line no-use-before-define

tests/JSON.test.ts

@@ -292,6 +292,7 @@ describe('GraphQLJSONObject', () => {
       }).then(({ data, errors }) => {
         expect(data).toBeUndefined();
         expect(errors).toBeDefined();
+        expect(errors).toMatchSnapshot();
       }));
 
     it('should reject array literal', () =>

tests/__snapshots__/JSON.test.ts.snap

@@ -0,0 +1,7 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`GraphQLJSONObject parseLiteral should reject string literal 1`] = `
+[
+  [GraphQLError: JSONObject cannot represent non-object value: "foo"],
+]
+`;