app.js

// # Special function to handle throwing error globally within every route and middleware
import '#lib/routerExceptionHandler';

// # Package imports
import cors from 'cors';
import helmet from 'helmet';
import morgan from 'morgan';
import express from 'express';
import cookieParser from 'cookie-parser';

// # Other imports
import log from '#logger';
import config from '#config';
import routes from '#routes';
import { idLogsMiddleware, rateLimiterMiddleware } from '#middlewares';
import { normalErrorHandler, standardErrorHandler, finalErrorHandler } from '#lib/responseHandlers';

// # Create express application
let app = express();

// # Check proxy enabled or not
if (config.proxy) app.set('trust proxy', config.proxy);

// # Remove x-powered-by header
app.disable('x-powered-by');

const corsOptions = {
  credentials: true,
  origin: function (origin, callback) {
    if (config.isDev || !origin || ~config.corsWhitelist.indexOf(origin)) callback(null, true);
    else callback(new Error('Not allowed by CORS'), null);
  },
};

const morganConfig = {
  stream: { write: (msg) => log.info(msg.trim()) },
};

app.use('/', express.static('public'));

// # Setup middlewares
app.use(idLogsMiddleware);
app.use(morgan(config.isDev ? 'dev' : 'combined', morganConfig));
app.use(helmet());
app.use(cors(corsOptions));
app.use(cookieParser());
app.use(express.json());
app.use(express.urlencoded({ extended: false }));

app.use(rateLimiterMiddleware);

// # Initialize routes
app.use(routes);

// # Error handlers
app.use(normalErrorHandler);
app.use(standardErrorHandler);
app.use(finalErrorHandler);

export default app;