refactor: Use graphql schema directly with graphql-tools library

packages/backend/src/graphql/mutations/login.ts

@@ -1,6 +1,4 @@
-import { GraphQLString, GraphQLNonNull } from 'graphql';
 import User from '../../models/user';
-import authType from '../types/auth';
 import jwt from 'jsonwebtoken';
 import appConfig from '../../config/app';
 
@@ -9,7 +7,7 @@ type Params = {
   password: string;
 };
 
-const loginResolver = async (params: Params) => {
+const login = async (_parent: unknown, params: Params) => {
   const user = await User.query().findOne({
     email: params.email,
   });
@@ -23,13 +21,4 @@ const loginResolver = async (params: Params) => {
   throw new Error('User could not be found.');
 };
 
-const login = {
-  type: authType,
-  args: {
-    email: { type: GraphQLNonNull(GraphQLString) },
-    password: { type: GraphQLNonNull(GraphQLString) },
-  },
-  resolve: (_: any, params: any) => loginResolver(params),
-};
-
 export default login;