can't run apollo-server-express with merged typeDefs and resolvers using #graphql-tools/merge - apollo

Question

hey friends this is the structure of my project and files down below:
starting from app.js file:
import { Server } from "./src/Server";
import { config } from "dotenv";
config();
Server.StartServer();
Down below is the Server.ts file that is bootstrapping of the apollo-server-express
import express from "express";
import http from "http";
import { ApolloServer } from "apollo-server-express";
import { GraphQLServerOptions } from "apollo-server-core/src/graphqlOptions";
import { schema } from "./graphql/index";
export class Server {
public static StartServer() {
const app: express.Application = express();
const server = new ApolloServer({
schema,
graphiql: true,
} as unknown as GraphQLServerOptions);
server.applyMiddleware({ app });
const httpServer = http.createServer(app);
server.installSubscriptionHandlers(httpServer);
httpServer.listen(process.env.PORT, function () {
console.log(`server is running on port ${process.env.PORT}`);
});
}
}
this is user.resolvers.ts file that my resolver goes here:
import { IResolvers } from "graphql-tools";
export const resolver: IResolvers = {
Mutation: {
register: function (parent, args, content, info) {
console.log(parent);
},
},
Query: {
getUser: function (parent, args, content, info) {
console.log(parent);
},
},
};
And here we go with the typeDef for in user.schema.ts file:
import { gql } from "apollo-server-express";
export const typeDef = gql`
type User {
username: String
password: String
}
type Mutation {
register(input: {username: String!, passwprd: String!})
}
type Query {
getUSer(username): User
}
`;
And finally over there in ./src/graphql/index.ts file I'm doing the mergig for resolvers and typeDefs there and I'm making the executableSchema for adding it to ApolloServer config object but I face the error below:
Any Ideas and suggestions would be greatly appreciated. Early thanks for the contributors :)