refactor(utils): Consolidate reload function into utils module

Author: wajeht

src/app.ts

@@ -9,12 +9,12 @@ import {
 import ejs from 'ejs';
 import cors from 'cors';
 import express from 'express';
+import { reload } from './utils';
 import flash from 'connect-flash';
 import { router } from './router';
 import { appConfig } from './config';
 import compression from 'compression';
 import expressLayouts from 'express-ejs-layouts';
-import { reload } from './reload';
 
 const app = express();
 

src/reload.ts

@@ -7,15 +7,16 @@ import jwt from 'jsonwebtoken';
 import dayjsModule from 'dayjs';
 import { Redis } from 'ioredis';
 import { logger } from './logger';
-import fs from 'node:fs/promises';
-import { Request } from 'express';
+import fsp from 'node:fs/promises';
+import fs from 'node:fs';
 import utc from 'dayjs/plugin/utc';
 import nodemailer from 'nodemailer';
 import { db, redis } from './db/db';
 import { Queue, Worker, Job } from 'bullmq';
 import timezone from 'dayjs/plugin/timezone';
 import { appConfig, emailConfig, oauthConfig, sessionConfig } from './config';
 import { GithubUserEmail, GitHubOauthToken, ApiKeyPayload, User } from './types';
+import { Application, Request, Response, NextFunction } from 'express';
 
 export function dayjs(date: string | Date = new Date()) {
 	dayjsModule.extend(utc);
@@ -234,7 +235,7 @@ export async function sendGeneralEmail({
 	message: string;
 }) {
 	try {
-		const templateContent = await fs.readFile(
+		const templateContent = await fsp.readFile(
 			path.resolve(path.join(process.cwd(), 'src', 'views', 'emails', 'general.html')),
 			'utf-8',
 		);
@@ -284,3 +285,66 @@ export const modifyUserSessionById = async (
 	logger.error('No session found for user ID:', userId);
 	return null;
 };
+
+export function reload({
+	app,
+	watch,
+	options = {},
+}: {
+	app: Application;
+	watch: { path: string; extensions: string[] }[];
+	options?: { pollInterval?: number; quiet?: boolean };
+}): void {
+	if (appConfig.env !== 'development') return;
+
+	const pollInterval = options.pollInterval || 50;
+	const quiet = options.quiet || false;
+	let changeDetected = false;
+
+	watch.forEach(({ path: dir, extensions }) => {
+		const extensionsSet = new Set(extensions);
+		fs.watch(dir, { recursive: true }, (_: fs.WatchEventType, filename: string | null) => {
+			if (filename && extensionsSet.has(filename.slice(filename.lastIndexOf('.')))) {
+				if (!quiet) logger.info('[reload] File changed: %s', filename);
+				changeDetected = true;
+			}
+		});
+	});
+
+	app.get('/wait-for-reload', (req: Request, res: Response) => {
+		const timer = setInterval(() => {
+			if (changeDetected) {
+				changeDetected = false;
+				clearInterval(timer);
+				res.send();
+			}
+		}, pollInterval);
+
+		req.on('close', () => clearInterval(timer));
+	});
+
+	const clientScript = `
+    <script>
+    	(async function poll() {
+        	try {
+            	await fetch('/wait-for-reload');
+            	location.reload();
+        	} catch {
+            	location.reload();
+        	}
+    	})();
+    </script>\n\t`;
+
+	app.use((req: Request, res: Response, next: NextFunction) => {
+		const originalSend = res.send.bind(res);
+
+		res.send = function (body: any): Response {
+			if (typeof body === 'string' && body.includes('</head>')) {
+				body = body.replace('</head>', clientScript + '</head>');
+			}
+			return originalSend(body);
+		};
+
+		next();
+	});
+}