undefined context

[vyperrrr]

`var express = require("express");
var { createHandler } = require("graphql-http/lib/use/express");
var { ruruHTML } = require("ruru/server");
import typeDefs from "./graphql/schema";
import resolvers from "./graphql/resolvers";
import { PrismaClient } from "@prisma/client";

var db = new PrismaClient();

var app = express();

app.all(
"/graphql",
createHandler({
schema: typeDefs,
rootValue: resolvers,
context: () => ({ db }),
})
);

app.get("/", (_req: any, res: any) => {
res.type("html");
res.end(ruruHTML({ endpoint: "/graphql" }));
});

app.listen(4000);
console.log("Running a GraphQL API server at http://localhost:4000/graphql");
`
Context is undefined, i tried every syntax put something into the context and it is always undefined, please help me