rallly/packages/backend/trpc/context.ts

import { createProxySSGHelpers } from "@trpc/react-query/ssg";
import * as trpc from "@trpc/server";
import * as trpcNext from "@trpc/server/adapters/next";
import { GetServerSidePropsContext } from "next";
import superjson from "superjson";

import { randomid } from "../utils/nanoid";
import { appRouter } from "./routers";

export async function createContext(
  opts: trpcNext.CreateNextContextOptions | GetServerSidePropsContext,
) {
  let user = opts.req.session.user;
  if (!user) {
    user = {
      id: `user-${randomid()}`,
      isGuest: true,
    };
    opts.req.session.user = user;
    await opts.req.session.save();
  }
  return { user, session: opts.req.session, req: opts.req, res: opts.res };
}

export type Context = trpc.inferAsyncReturnType<typeof createContext>;

export const createSSGHelperFromContext = async (
  ctx: GetServerSidePropsContext,
) =>
  createProxySSGHelpers({
    router: appRouter,
    ctx: await createContext(ctx),
    transformer: superjson,
  });