index.js

const express = require("express");
const app = express();
const dotenv = require("dotenv");
const mongoose = require("mongoose");
const authRoute = require("./routes/auth");
const userRoute = require("./routes/users");
const postRoute = require("./routes/posts");
const categoryRoute = require("./routes/categories");
const uploadRoute = require("./routes/upload");

dotenv.config();
app.use(express.json());
app.use((req, res, next) => {
  res.header("Access-Control-Allow-Origin", "http://localhost:3000");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept, Authorization");
  res.header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
  if (req.method === "OPTIONS") return res.sendStatus(200);
  next();
});

mongoose
  .connect(process.env.MONGO_URL, {
    useNewUrlParser: true,
    useUnifiedTopology: true,
    useCreateIndex: true,
    useFindAndModify: true,
  })
  .then(console.log("Connected to MongoDB"))
  .catch((err) => console.log(err));

app.use("/api/auth", authRoute);
app.use("/api/users", userRoute);
app.use("/api/posts", postRoute);
app.use("/api/categories", categoryRoute);
app.use("/api/upload", uploadRoute);

app.listen("5000", () => {
  console.log("Backend is running.");
});