JavaScript Express Basics Parameters, Query Strings, and Modularizing Routes Randomize Cards

Dehn Hunsworth
Dehn Hunsworth
7,189 Points

cant get server running

Been following the code pretty exact i believe but I am unable to even get the server going. error message that appears in terminal not much help.

Here is the message:

[nodemon] starting `node app.js`
C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\path-to-regexp\index.js:63
  path = ('^' + path + (strict ? '' : path[path.length - 1] === '/' ? '?' : '/?'))

TypeError: Cannot read property 'length' of undefined
    at pathtoRegexp (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\path-to-regexp\index.js:63:49)
    at new Layer (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\express\lib\router\layer.js:45:17)
    at Function.use (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\express\lib\router\index.js:464:17)
    at Function.<anonymous> (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\express\lib\application.js:220:21)
    at Array.forEach (<anonymous>)
    at Function.use (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\express\lib\application.js:217:7)
    at Object.<anonymous> (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\app.js:16:5)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
[nodemon] app crashed - waiting for file changes before starting...

and the cards.js where I had been making the most recent changes:

const express = require("express");
const router = express.Router();
const { data } = require("../data/flashcardData.json");
const { cards } = data;

router.get("/", (req, res) => {
   const numberOfCards = cards.length;
   const flashCardId = Math.floor(Math.random() * numberOfCards);

router.get("/:id", (req, res) => {
   const { side } = req.query;
   const { id } = req.params;
   const text = cards[id][side];
   const { hint } = cards[id];

   const templateData = { id, text };

   if (side === "question") {
      templateData.hint = hint;
      templateData.sideToShow = "answer";
   } else if (side === "answer") {
      templateData.sideToShow = "question";

   res.render("card", templateData);

module.exports = router;

Sure it is something simple but i have been looking at it for hours and my head hurts... Thanks.

Dehn Hunsworth
Dehn Hunsworth
7,189 Points

Deleted a variable from my app.js that was just a test and unused and still no server but the message has changed.

:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\express\lib\application.js:210
    throw new TypeError('app.use() requires a middleware function')

TypeError: app.use() requires a middleware function
    at Function.use (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\node_modules\express\lib\application.js:210:11)
    at Object.<anonymous> (C:\Users\The Huns\Desktop\Web-Dev\Team Treehouse\flashcardsExpress\app.js:15:5)
    at Module._compile (internal/modules/cjs/loader.js:689:30)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:700:10)
    at Module.load (internal/modules/cjs/loader.js:599:32)
    at tryModuleLoad (internal/modules/cjs/loader.js:538:12)
    at Function.Module._load (internal/modules/cjs/loader.js:530:3)
    at Function.Module.runMain (internal/modules/cjs/loader.js:742:12)
    at startup (internal/bootstrap/node.js:283:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:743:3)
[nodemon] app crashed - waiting for file changes before starting...

and the app.js :

const express = require("express");
const bodyParser = require("body-parser");
const cookieParser = require("cookie-parser");

const app = express();

app.use(bodyParser.urlencoded({ extended: false }));

app.set("view engine", "pug");

const mainRoutes = require("./routes").default;
const cardRoutes = require("./routes/cards");

app.use("/cards", cardRoutes);

app.use((req, res, next) => {
   const err = new Error("Not Found");
   err.status = 404;

app.use((err, req, res, next) => {
   res.locals.error = err;
   res.render("error", err);

app.listen(3000, () => {
   console.log("The application is running on port 3000.");