app.js

//config files and packages
require("express-async-errors");
require("dotenv").config();

//basic imports
const express = require("express");
const app = express();
const mongoose = require("mongoose");
const cookieParser = require("cookie-parser");

//Handling uncaught exceptions
process.on("uncaughtException", (err) => {
  console.log(err.message);
  console.log(`Server is shutting down due to uncaught exception`);
  process.exit(1);
});

//basic middlware imports
app.use(express.json());
app.use(cookieParser());

//custom middleware imports
const errorHandlerMiddleware = require("./middleware/error-handler");
const notFound = require("./middleware/not-found");

//monogoose deprecations
mongoose.set("strictQuery", true);

//db import
const connectDB = require("./db/connect");

//const route imports
const productRouter = require("./routes/productRouter");
const userRouter = require("./routes/userRouter");
const orderRouter = require("./routes/orderRouter");

//routes
app.get("/api/v1/docs", (req, res) => {
  res.send();
});
app.use("/api/v1", productRouter);
app.use("/api/v1", userRouter);
app.use("/api/v1", orderRouter);
app.use(errorHandlerMiddleware);
app.use(notFound);

//const server and connect and start
const port = process.env.PORT || 3000;
const start = async () => {
  try {
    await connectDB(process.env.MONGO_URI);
    const server = app.listen(port, () => {
      console.log(`Server running on port ${port}`);
    });
  } catch (err) {
    console.log(err);
  }
};

start();

//Handling unhandled promise rejection
process.on("unhandledRejection", (err) => {
  console.log(err.message);
  console.log(`Server is shutting down due to unhandled promise rejection`);
  server.close(() => {
    process.exit(1);
  });
});