Cloudflare Developers•13mo ago

"The script will never generate a response"

I have no idea where to even start looking, or even how to reproduce. I read this article https://zuplo.com/blog/2022/03/04/the-script-will-never-generate-a-response and I think this may be what is going on. But I have no idea what can I do to start troubleshooting. I am using Sveltekit and in hooks.server.ts I validate a session cookie and get/put data using Cloudflare's KV. I do notice if I refresh the page several times I can see the error in the logs:

  "exceptions": [
    {
      "name": "Error",
      "message": "The script will never generate a response.",
      "timestamp": 1700096259217
    }
  ],

  "exceptions": [
    {
      "name": "Error",
      "message": "The script will never generate a response.",
      "timestamp": 1700096259217
    }
  ],

Zuplo

"The script will never generate a response" on CloudFlare Workers |...

2 Replies

kian•13mo ago

Do you have an example of your code that has this issue?

Ricardo ViteriOP•13mo ago

Hi @kian , this is the code in handle function:

import { handleSessionIdleState, validateSession } from "./cookie-manager";
import { redirect, type Handle } from "@sveltejs/kit";

import { PUBLIC_SESSION_COOKIE_NAME } from "$env/static/public";

import type { SessionData } from "../../login/proxy+page.server";

const config = {
    loginRouteId: "/(public)/login",
    loginPagePath: "/login"
};

type SessionStatus = "expired" | "active" | "idle" | undefined | null;

import { handleSessionIdleState, validateSession } from "./cookie-manager";
import { redirect, type Handle } from "@sveltejs/kit";

import { PUBLIC_SESSION_COOKIE_NAME } from "$env/static/public";

import type { SessionData } from "../../login/proxy+page.server";

const config = {
    loginRouteId: "/(public)/login",
    loginPagePath: "/login"
};

type SessionStatus = "expired" | "active" | "idle" | undefined | null;

const validateAndUpdateCookieSession: Handle = async ({ event, resolve }) => {
    const kv = event.platform?.env?.AUTH_SESSIONS;
    const cookieValue = event.cookies.get(PUBLIC_SESSION_COOKIE_NAME);
    const storedSessionData = await kv?.get(String(cookieValue));

    if (!storedSessionData) {
        console.log("No session data found");
        event.locals.sessionState = null;
        return await resolve(event);
    }

    const storedSession = JSON.parse(storedSessionData);

    let cookieSessionState: SessionStatus = await validateSession(
        storedSession?.cookieExpirationDate
    );
    event.locals.sessionState = cookieSessionState;

    switch (cookieSessionState) {
        case "active":
            break;

        case "expired":
            event.cookies.set(PUBLIC_SESSION_COOKIE_NAME, "", {
                secure: false,
                sameSite: "lax",
                httpOnly: true,
                path: "/",
                domain: undefined,
                maxAge: 0
            });
            break;
        case "idle":
            const { newCookie, newExpirationDate } = handleSessionIdleState(String(cookieValue));
            const data: SessionData = { ...storedSession, cookieExpirationDate: newExpirationDate };
            await kv?.put(newCookie.value, JSON.stringify(data));
            event.cookies.set(newCookie.name, newCookie.value, newCookie.attributes);
            break;
        default:
            break;
    }

    return await resolve(event);
};

const validateAndUpdateCookieSession: Handle = async ({ event, resolve }) => {
    const kv = event.platform?.env?.AUTH_SESSIONS;
    const cookieValue = event.cookies.get(PUBLIC_SESSION_COOKIE_NAME);
    const storedSessionData = await kv?.get(String(cookieValue));

    if (!storedSessionData) {
        console.log("No session data found");
        event.locals.sessionState = null;
        return await resolve(event);
    }

    const storedSession = JSON.parse(storedSessionData);

    let cookieSessionState: SessionStatus = await validateSession(
        storedSession?.cookieExpirationDate
    );
    event.locals.sessionState = cookieSessionState;

    switch (cookieSessionState) {
        case "active":
            break;

        case "expired":
            event.cookies.set(PUBLIC_SESSION_COOKIE_NAME, "", {
                secure: false,
                sameSite: "lax",
                httpOnly: true,
                path: "/",
                domain: undefined,
                maxAge: 0
            });
            break;
        case "idle":
            const { newCookie, newExpirationDate } = handleSessionIdleState(String(cookieValue));
            const data: SessionData = { ...storedSession, cookieExpirationDate: newExpirationDate };
            await kv?.put(newCookie.value, JSON.stringify(data));
            event.cookies.set(newCookie.name, newCookie.value, newCookie.attributes);
            break;
        default:
            break;
    }

    return await resolve(event);
};

const handleLogin: Handle = async ({ event, resolve }) => {
    const sessionStatus: SessionStatus = event.locals.sessionState;

    console.log("Session Status", sessionStatus);
    if (!sessionStatus) {
        if (event.route.id?.includes(config.loginRouteId)) {
            // Continue with the request resolution
            return await resolve(event);
        } else {
            throw redirect(303, config.loginPagePath);
        }
    }

    if (
        (event.route.id?.includes(config.loginRouteId) && sessionStatus === "active") ||
        sessionStatus === "idle"
    ) {
        throw redirect(303, "/");
    }

    return await resolve(event);
};

const handleLogin: Handle = async ({ event, resolve }) => {
    const sessionStatus: SessionStatus = event.locals.sessionState;

    console.log("Session Status", sessionStatus);
    if (!sessionStatus) {
        if (event.route.id?.includes(config.loginRouteId)) {
            // Continue with the request resolution
            return await resolve(event);
        } else {
            throw redirect(303, config.loginPagePath);
        }
    }

    if (
        (event.route.id?.includes(config.loginRouteId) && sessionStatus === "active") ||
        sessionStatus === "idle"
    ) {
        throw redirect(303, "/");
    }

    return await resolve(event);
};

const injectLocals: Handle = async ({ event, resolve }) => {
    const sessionStatus: SessionStatus = event.locals.sessionState;
    if (!sessionStatus || sessionStatus === "expired") {
        return await resolve(event);
    }

    const kv = event.platform?.env?.AUTH_SESSIONS;
    const cookieValue = event.cookies.get(PUBLIC_SESSION_COOKIE_NAME);
    const storedSessionData = await kv?.get(String(cookieValue));

    const { loginData } = JSON.parse(storedSessionData as string);

    event.locals.loginData = loginData;

    return await resolve(event);
};

const injectLocals: Handle = async ({ event, resolve }) => {
    const sessionStatus: SessionStatus = event.locals.sessionState;
    if (!sessionStatus || sessionStatus === "expired") {
        return await resolve(event);
    }

    const kv = event.platform?.env?.AUTH_SESSIONS;
    const cookieValue = event.cookies.get(PUBLIC_SESSION_COOKIE_NAME);
    const storedSessionData = await kv?.get(String(cookieValue));

    const { loginData } = JSON.parse(storedSessionData as string);

    event.locals.loginData = loginData;

    return await resolve(event);
};

export const AuthHooks = [validateAndUpdateCookieSession, handleLogin, injectLocals];

export const AuthHooks = [validateAndUpdateCookieSession, handleLogin, injectLocals];

I am noticing that this error occurs when I quickly reload the page. This error also happened on another project, and it seems to happen when something is being fetched by the load function.

Gaming

Programming

"The script will never generate a response"