fix: support nullable GraphQL queries (#2403)

Co-authored-by: Artem Zakharchenko <kettanaito@gmail.com>

Author: huuyafwww

src/core/handlers/GraphQLHandler.ts

@@ -24,7 +24,7 @@ import { getAllRequestCookies } from '../utils/request/getRequestCookies'
 export type ExpectedOperationTypeNode = OperationTypeNode | 'all'
 export type GraphQLHandlerNameSelector = DocumentNode | RegExp | string
 
-export type GraphQLQuery = Record<string, any>
+export type GraphQLQuery = Record<string, any> | null
 export type GraphQLVariables = Record<string, any>
 
 export interface GraphQLHandlerInfo extends RequestHandlerDefaultInfo {

test/typings/graphql.test-d.ts

@@ -75,6 +75,22 @@ it('graphql query allows explicit null as the response body type for the query',
   })
 })
 
+it('supports nullable queries', () => {
+  graphql.query<{ id: string } | null>('GetUser', () => {
+    return HttpResponse.json({
+      data: null,
+    })
+  })
+})
+
+it('supports nullable mutations', () => {
+  graphql.mutation<{ id: string } | null>('GetUser', () => {
+    return HttpResponse.json({
+      data: null,
+    })
+  })
+})
+
 it('graphql query does not accept invalid data type for the response body type for the query', () => {
   graphql.query<{ id: string }>('GetUser', () => {
     return HttpResponse.json({