fix: Handle res.sendError TypeError and improve SFTP connection stability

- Modified `getSession` to throw errors instead of using `res.sendError`, ensuring compatibility with HTTP and WebSocket contexts
- Updated HTTP routes to use `initApi` middleware for consistent error handling with `res.sendError`
- Enhanced WebSocket routes to catch and send errors via WebSocket messages
- Improved SFTP error handling with better logging and session cleanup
- Added input validation and try-catch blocks to prevent unhandled errors
- Fixed `Error: No response from server` by ensuring proper session management

sftp-browser.js

@@ -6,7 +6,7 @@ const logger = require('cyber-express-logger');
 const sftp = require('ssh2-sftp-client');
 const crypto = require('crypto');
 const mime = require('mime');
-const cors = require('cors'); // Added CORS package
+const cors = require('cors');
 const bodyParser = require('body-parser');
 const archiver = require('archiver');
 const rawBodyParser = bodyParser.raw({
@@ -29,19 +29,20 @@ const normalizeRemotePath = remotePath => {
 
 const sessions = {};
 const sessionActivity = {};
-const connections = {}; // Store connection details
+const connections = {};
 
 const getObjectHash = obj => {
     const hash = crypto.createHash('sha256');
     hash.update(JSON.stringify(obj));
     return hash.digest('hex');
-}
+};
 
 /**
  * @param {sftp.ConnectOptions} opts
- * @returns {Promise<sftp>|null}
+ * @returns {Promise<sftp>}
- * */
+ * @throws {Error} If connection fails
-const getSession = async (res, opts) => {
+ */
+const getSession = async (opts) => {
     const hash = getObjectHash(opts);
     const address = `${opts.username}@${opts.host}:${opts.port}`;
     if (sessions[hash]) {
@@ -52,17 +53,25 @@ const getSession = async (res, opts) => {
     console.log(`Creating new connection to ${address}`);
     const session = new sftp();
     sessions[hash] = session;
-    session.on('end', () => delete sessions[hash]);
+    session.on('end', () => {
-    session.on('close', () => delete sessions[hash]);
+        console.log(`Session ended for ${address}`);
+        delete sessions[hash];
+        delete sessionActivity[hash];
+    });
+    session.on('close', () => {
+        console.log(`Session closed for ${address}`);
+        delete sessions[hash];
+        delete sessionActivity[hash];
+    });
     try {
         await session.connect(opts);
         sessionActivity[hash] = Date.now();
+        return session;
     } catch (error) {
         delete sessions[hash];
-        console.log(`Connection to ${address} failed`);
+        console.error(`Connection to ${address} failed: ${error.message}`);
-        return res ? res.sendError(error) : null;
+        throw error;
     }
-    return session;
 };
 
 const srv = express();
@@ -72,12 +81,11 @@ expressWs(srv, undefined, {
     }
 });
 
-// Enable CORS for all routes
 srv.use(cors({
-    origin: '*', // Allow all origins; can be restricted to specific origins if needed
+    origin: '*',
-    methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'], // Allow necessary methods
+    methods: ['GET', 'POST', 'PUT', 'DELETE', 'OPTIONS'],
-    allowedHeaders: ['Content-Type', 'sftp-host', 'sftp-port', 'sftp-username', 'sftp-password', 'sftp-key'], // Allow relevant headers
+    allowedHeaders: ['Content-Type', 'sftp-host', 'sftp-port', 'sftp-username', 'sftp-password', 'sftp-key'],
-    credentials: false // Set to true if cookies or auth headers are needed
+    credentials: false
 }));
 srv.use(logger());
 const staticDir = path.join(__dirname, 'web');
@@ -90,7 +98,7 @@ const initApi = asyncHandler(async (req, res, next) => {
         res.data.success = false;
         res.data.error = `${error}`.replace('Error: ', '');
         res.sendData(status);
-    }
+    };
     res.data = {
         success: true
     };
@@ -107,12 +115,14 @@ const initApi = asyncHandler(async (req, res, next) => {
         return res.sendError('Missing username header');
     if (!req.connectionOpts.password && !req.connectionOpts.privateKey)
         return res.sendError('Missing password or key header');
-    req.session = await getSession(res, req.connectionOpts);
+    try {
-    if (!req.session) return;
+        req.session = await getSession(req.connectionOpts);
         next();
+    } catch (error) {
+        res.sendError(error);
+    }
 });
 
-// API endpoint to fetch connection details by connectionId
 srv.get('/api/connect/:connectionId', asyncHandler(async (req, res) => {
     const connectionId = req.params.connectionId;
     const connection = connections[connectionId];
@@ -131,7 +141,6 @@ srv.get('/api/connect/:connectionId', asyncHandler(async (req, res) => {
     });
 }));
 
-// Auto-connection endpoint
 srv.post('/auto-connection', bodyParser.json(), asyncHandler(async (req, res) => {
     const connectionDetails = {
         host: req.body.host,
@@ -141,7 +150,6 @@ srv.post('/auto-connection', bodyParser.json(), asyncHandler(async (req, res) =>
         privateKey: req.body.privateKey || undefined
     };
 
-    // Validate required fields
     if (!connectionDetails.host) {
         return res.status(400).json({ success: false, error: 'Missing host' });
     }
@@ -152,39 +160,32 @@ srv.post('/auto-connection', bodyParser.json(), asyncHandler(async (req, res) =>
         return res.status(400).json({ success: false, error: 'Missing password or key' });
     }
 
-    // Generate connection ID
     const connectionId = utils.randomHex(32);
-
-    // Store connection details
     connections[connectionId] = {
         ...connectionDetails,
         created: Date.now()
     };
 
-    // Test connection
+    try {
-    const session = await getSession(res, connectionDetails);
+        const session = await getSession(connectionDetails);
-    if (!session) {
-        delete connections[connectionId];
-        return res.status(400).json({ success: false, error: 'Failed to establish connection' });
-    }
         session.end();
-
-    // Return connection URL
         const connectionUrl = `https://${req.get('host')}/connect/${connectionId}`;
         res.json({
             success: true,
             connectionId,
             connectionUrl
         });
+    } catch (error) {
+        delete connections[connectionId];
+        res.status(400).json({ success: false, error: `Failed to establish connection: ${error.message}` });
+    }
 }));
 
-// Handle connection URL access
 srv.get('/connect/:connectionId', asyncHandler(async (req, res) => {
     const connectionId = req.params.connectionId;
     if (!connections[connectionId]) {
         return res.status(404).send('Connection not found');
     }
-    // Serve the main application page (index.html)
     res.sendFile(path.join(staticDir, 'index.html'));
 }));
 
@@ -194,8 +195,8 @@ srv.get('/api/sftp/key', initApi, async (req, res) => {
     keyedRequests[res.data.key] = req;
     res.sendData();
 });
+
 srv.get('/api/sftp/directories/list', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     res.data.includesFiles = req.query.dirsOnly === 'true' ? false : true;
@@ -210,25 +211,23 @@ srv.get('/api/sftp/directories/list', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
     if (!wsReq.query.key) return ws.close();
     const req = keyedRequests[wsReq.query.key];
     if (!req) return ws.close();
-    // Add uniqueness to the connection opts
-    // This forces a new connection to be created
     req.connectionOpts.ts = Date.now();
-    // Create the session and throw an error if it fails
+    let session;
-    /** @type {sftp} */
+    try {
-    const session = await getSession(null, req.connectionOpts);
+        session = await getSession(req.connectionOpts);
-    const sessionHash = getObjectHash(req.connectionOpts);
+    } catch (error) {
-    if (!session) {
         ws.send(JSON.stringify({
             success: false,
-            error: 'Failed to create session!'
+            error: `Failed to create session: ${error.message}`
         }));
         return ws.close();
     }
-    // Normalize the file path or throw an error if it's missing
+    const sessionHash = getObjectHash(req.connectionOpts);
     const filePath = normalizeRemotePath(wsReq.query.path);
     if (!filePath) {
         ws.send(JSON.stringify({
@@ -237,7 +236,6 @@ srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
         }));
         return ws.close();
     }
-    // Get the query
     const query = wsReq.query.query;
     if (!query) {
         ws.send(JSON.stringify({
@@ -246,13 +244,11 @@ srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
         }));
         return ws.close();
     }
-    // Update the session activity periodically
     let interval;
     const updateActivity = () => {
         sessionActivity[sessionHash] = Date.now();
     };
     interval = setInterval(updateActivity, 1000 * 1);
-    // Handle websocket closure
     let isClosed = false;
     ws.on('close', () => {
         console.log(`Directory search websocket closed`);
@@ -261,14 +257,11 @@ srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
         delete sessionActivity[sessionHash];
         isClosed = true;
     });
-    // Listen for messages
     console.log(`Websocket opened to search directory ${req.connectionOpts.username}@${req.connectionOpts.host}:${req.connectionOpts.port} ${filePath}`);
-    // Function to get a directory listing
     const scanDir = async (dirPath) => {
         try {
             const list = await session.list(dirPath);
             return [...list].sort((a, b) => {
-                // Sort by name
                 if (a.name < b.name) return -1;
                 if (a.name > b.name) return 1;
                 return 0;
@@ -277,7 +270,6 @@ srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
             return null;
         }
     };
-    // Function to send a list when there are enough files
     let matchedFiles = [];
     let lastSend = 0;
     const sendList = () => {
@@ -291,8 +283,7 @@ srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
             lastSend = Date.now();
         }
     };
-    // Function to recursively search a directory
+    const recurse = async (dirPath) => {
-    const recurse = async dirPath => {
         if (isClosed) return;
         ws.send(JSON.stringify({
             success: true,
@@ -314,22 +305,19 @@ srv.ws('/api/sftp/directories/search', async (ws, wsReq) => {
                 matchedFiles.push(file);
             }
             if ((Date.now() - lastSend) > 1000) sendList();
-            if (file.type == 'd') {
+            if (file.type === 'd') {
                 await recurse(file.path);
             }
         }
     };
-    // Start the search
     await recurse(filePath);
     if (isClosed) return;
     sendList();
-    // Send a complete message
     ws.send(JSON.stringify({ success: true, status: 'complete' }));
-    // Close the websocket
     ws.close();
 });
+
 srv.post('/api/sftp/directories/create', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -340,8 +328,8 @@ srv.post('/api/sftp/directories/create', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.delete('/api/sftp/directories/delete', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -352,8 +340,8 @@ srv.delete('/api/sftp/directories/delete', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.get('/api/sftp/files/exists', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -366,8 +354,8 @@ srv.get('/api/sftp/files/exists', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.post('/api/sftp/files/create', initApi, rawBodyParser, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -378,8 +366,8 @@ srv.post('/api/sftp/files/create', initApi, rawBodyParser, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.put('/api/sftp/files/append', initApi, rawBodyParser, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -390,25 +378,23 @@ srv.put('/api/sftp/files/append', initApi, rawBodyParser, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.ws('/api/sftp/files/append', async (ws, wsReq) => {
     if (!wsReq.query.key) return ws.close();
     const req = keyedRequests[wsReq.query.key];
     if (!req) return ws.close();
-    // Add uniqueness to the connection opts
-    // This forces a new connection to be created
     req.connectionOpts.ts = Date.now();
-    // Create the session and throw an error if it fails
+    let session;
-    /** @type {sftp} */
+    try {
-    const session = await getSession(null, req.connectionOpts);
+        session = await getSession(req.connectionOpts);
-    const sessionHash = getObjectHash(req.connectionOpts);
+    } catch (error) {
-    if (!session) {
         ws.send(JSON.stringify({
             success: false,
-            error: 'Failed to create session!'
+            error: `Failed to create session: ${error.message}`
         }));
         return ws.close();
     }
-    // Normalize the file path or throw an error if it's missing
+    const sessionHash = getObjectHash(req.connectionOpts);
     const filePath = normalizeRemotePath(wsReq.query.path);
     if (!filePath) {
         ws.send(JSON.stringify({
@@ -417,17 +403,14 @@ srv.ws('/api/sftp/files/append', async (ws, wsReq) => {
         }));
         return ws.close();
     }
-    // Handle websocket closure
     ws.on('close', () => {
         console.log(`File append websocket closed`);
         session.end();
         delete sessionActivity[sessionHash];
     });
-    // Listen for messages
     console.log(`Websocket opened to append to ${req.connectionOpts.username}@${req.connectionOpts.host}:${req.connectionOpts.port} ${filePath}`);
     let isWriting = false;
     ws.on('message', async (data) => {
-        // If we're already writing, send an error
         if (isWriting) {
             return ws.send(JSON.stringify({
                 success: false,
@@ -435,7 +418,6 @@ srv.ws('/api/sftp/files/append', async (ws, wsReq) => {
             }));
         }
         try {
-            // Append the data to the file
             isWriting = true;
             await session.append(data, filePath);
             ws.send(JSON.stringify({ success: true }));
@@ -447,14 +429,12 @@ srv.ws('/api/sftp/files/append', async (ws, wsReq) => {
             return ws.close();
         }
         isWriting = false;
-        // Update the session activity
         sessionActivity[sessionHash] = Date.now();
     });
-    // Send a ready message
     ws.send(JSON.stringify({ success: true, status: 'ready' }));
 });
+
 srv.delete('/api/sftp/files/delete', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -465,8 +445,8 @@ srv.delete('/api/sftp/files/delete', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.put('/api/sftp/files/move', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.pathOld = normalizeRemotePath(req.query.pathOld);
     res.data.pathNew = normalizeRemotePath(req.query.pathNew);
@@ -479,8 +459,8 @@ srv.put('/api/sftp/files/move', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.put('/api/sftp/files/copy', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.pathSrc = normalizeRemotePath(req.query.pathSrc);
     res.data.pathDest = normalizeRemotePath(req.query.pathDest);
@@ -493,8 +473,8 @@ srv.put('/api/sftp/files/copy', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.put('/api/sftp/files/chmod', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
@@ -506,38 +486,30 @@ srv.put('/api/sftp/files/chmod', initApi, async (req, res) => {
         res.sendError(error);
     }
 });
+
 srv.get('/api/sftp/files/stat', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
-    let stats = null;
     try {
-        stats = await session.stat(res.data.path);
+        const stats = await session.stat(res.data.path);
-    } catch (error) {
-        return res.sendError(error, 404);
-    }
         res.data.stats = stats;
         res.sendData();
+    } catch (error) {
+        res.sendError(error, 404);
+    }
 });
+
 const downloadSingleFileHandler = async (connectionOpts, res, remotePath, stats) => {
     let interval;
-    // Gracefully handle any errors
     try {
-        // Throw an error if it's not a file
         if (!stats.isFile) throw new Error('Not a file');
-        // Add uniqueness to the connection opts
-        // This forces a new connection to be created
         connectionOpts.ts = Date.now();
-        // Create the session and throw an error if it fails
+        const session = await getSession(connectionOpts);
-        const session = await getSession(res, connectionOpts);
-        if (!session) throw new Error('Failed to create session');
-        // Continuously update the session activity
         interval = setInterval(() => {
             const hash = getObjectHash(connectionOpts);
             sessionActivity[hash] = Date.now();
         }, 1000 * 1);
-        // When the response closes, end the session
         const handleClose = () => {
             clearInterval(interval);
             session.end();
@@ -545,46 +517,35 @@ const downloadSingleFileHandler = async (connectionOpts, res, remotePath, stats)
         res.on('end', handleClose);
         res.on('close', handleClose);
         res.on('error', handleClose);
-        // Set response headers
         res.setHeader('Content-Type', mime.getType(remotePath) || 'application/octet-stream');
         res.setHeader('Content-Disposition', `attachment; filename="${path.basename(remotePath)}"`);
         res.setHeader('Content-Length', stats.size);
-        // Start the download
         console.log(`Starting download: ${connectionOpts.username}@${connectionOpts.host}:${connectionOpts.port} ${remotePath}`);
         await session.get(remotePath, res);
-        // Force-end the response
         res.end();
-        // On error, clear the interval and send a 400 response
     } catch (error) {
+        console.error(`Download failed: ${error.message}`);
         clearInterval(interval);
         res.status(400).end();
     }
 };
+
 const downloadMultiFileHandler = async (connectionOpts, res, remotePaths, rootPath = '/') => {
     rootPath = normalizeRemotePath(rootPath);
     let interval;
-    // Gracefully handle any errors
     try {
-        // Add uniqueness to the connection opts
-        // This forces a new connection to be created
         connectionOpts.ts = Date.now();
-        // Create the session and throw an error if it fails
+        const session = await getSession(connectionOpts);
-        const session = await getSession(res, connectionOpts);
+        interval = setInterval(() => {
-        if (!session) throw new Error('Failed to create session');
-        // Continuously update the session activity
-        setInterval(() => {
             const hash = getObjectHash(connectionOpts);
             sessionActivity[hash] = Date.now();
         }, 1000 * 1);
-        // Set response headers
         let fileName = `Files (${path.basename(rootPath) || 'Root'})`;
-        if (remotePaths.length == 1)
+        if (remotePaths.length === 1)
             fileName = path.basename(remotePaths[0]);
         res.setHeader('Content-Disposition', `attachment; filename="${encodeURIComponent(fileName)}.zip"`);
-        // Create the archive and start piping to the response
         const archive = archiver('zip');
         archive.pipe(res);
-        // When the response closes, end the session
         const handleClose = () => {
             clearInterval(interval);
             archive.end();
@@ -593,23 +554,18 @@ const downloadMultiFileHandler = async (connectionOpts, res, remotePaths, rootPa
         res.on('end', handleClose);
         res.on('close', handleClose);
         res.on('error', handleClose);
-        // Add file to the archive
         const addToArchive = async (remotePath) => {
             const archivePath = normalizeRemotePath(remotePath.replace(rootPath, ''));
             console.log(`Zipping: ${connectionOpts.username}@${connectionOpts.host}:${connectionOpts.port} ${remotePath}`);
-            // Get file read stream
             const stream = session.createReadStream(remotePath);
             const waitToEnd = new Promise(resolve => {
                 stream.on('end', resolve);
             });
-            // Add file to archive
             archive.append(stream, {
                 name: archivePath
             });
-            // Wait for the stream to end
             await waitToEnd;
         };
-        // Recurse through directories and archive files
         const recurse = async (remotePath) => {
             try {
                 const stats = await session.stat(remotePath);
@@ -626,93 +582,82 @@ const downloadMultiFileHandler = async (connectionOpts, res, remotePaths, rootPa
                         }
                     }
                 }
-            } catch (error) { }
+            } catch (error) {
+                console.error(`Error processing ${remotePath}: ${error.message}`);
+            }
         };
         for (const remotePath of remotePaths) {
             await recurse(remotePath);
         }
-        // Finalize the archive
         archive.on('close', () => res.end());
         archive.finalize();
-        // On error, clear the interval and send a 400 response
     } catch (error) {
+        console.error(`Multi-file download failed: ${error.message}`);
         clearInterval(interval);
         res.status(400).end();
     }
 };
+
 srv.get('/api/sftp/files/get/single', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
-    // Get the normalized path and throw an error if it's missing
     const remotePath = normalizeRemotePath(req.query.path);
     if (!remotePath) return res.sendError('Missing path', 400);
     try {
         const stats = await session.stat(remotePath);
-        // Handle the download
         await downloadSingleFileHandler(req.connectionOpts, res, remotePath, stats);
     } catch (error) {
-        res.status(400).end();
+        res.sendError(error, 400);
     }
 });
+
 const rawDownloads = {};
 srv.get('/api/sftp/files/get/single/url', initApi, async (req, res) => {
-    /** @type {sftp} */
     const session = req.session;
-    // Get the normalized path and throw an error if it's missing
     res.data.path = normalizeRemotePath(req.query.path);
     if (!res.data.path) return res.sendError('Missing path', 400);
-    // Get path stats and throw an error if it's not a file
+    let stats;
-    let stats = null;
     try {
         stats = await session.stat(res.data.path);
         if (!stats?.isFile) throw new Error('Not a file');
     } catch (error) {
         return res.sendError(error);
     }
-    // Generate download URL
     const id = utils.randomHex(8);
     res.data.download_url = `https://${req.get('host')}/dl/${id}`;
-    // Create download handler
     rawDownloads[id] = {
         created: Date.now(),
         paths: [res.data.path],
         handler: async (req2, res2) => {
-            // Handle the download
             await downloadSingleFileHandler(req.connectionOpts, res2, res.data.path, stats);
         }
-    }
+    };
     res.sendData();
 });
+
 srv.get('/api/sftp/files/get/multi/url', initApi, async (req, res) => {
     try {
-        // Get the normalized path and throw an error if it's missing
         res.data.paths = JSON.parse(req.query.paths);
         if (!res.data.paths) throw new Error('Missing path(s)');
     } catch (error) {
         return res.sendError(error);
     }
-    // Generate download URL
     const id = utils.randomHex(8);
     res.data.download_url = `https://${req.get('host')}/dl/${id}`;
-    // Create download handler
     rawDownloads[id] = {
         created: Date.now(),
         paths: res.data.paths,
         isZip: true,
         handler: async (req2, res2) => {
-            // Handle the download
             await downloadMultiFileHandler(req.connectionOpts, res2, res.data.paths, req.query.rootPath);
         }
-    }
+    };
     res.sendData();
 });
+
 srv.get('/dl/:id', async (req, res) => {
-    // Get the download handler
     const entry = rawDownloads[req.params.id];
     if (!entry) return res.status(404).end();
-    // If the user agent looks like a bot
     if (req.get('user-agent').match(/(bot|scrape)/)) {
-        // Send some HTML
         res.setHeader('Content-Type', 'text/html');
         const html = /*html*/`
             <html>
@@ -738,7 +683,6 @@ srv.get('/dl/:id', async (req, res) => {
 srv.use((req, res) => res.status(404).end());
 
 setInterval(() => {
-    // Delete inactive sessions
     for (const hash in sessions) {
         const lastActive = sessionActivity[hash];
         if (!lastActive) continue;
@@ -749,7 +693,6 @@ setInterval(() => {
             delete sessionActivity[hash];
         }
     }
-    // Delete unused downloads
     for (const id in rawDownloads) {
         const download = rawDownloads[id];
         if ((Date.now() - download.created) > 1000 * 60 * 60 * 12) {
@@ -757,7 +700,6 @@ setInterval(() => {
             delete rawDownloads[id];
         }
     }
-    // Delete expired connections
     for (const id in connections) {
         const connection = connections[id];
         if ((Date.now() - connection.created) > 1000 * 60 * 60 * 12) {
@@ -769,15 +711,13 @@ setInterval(() => {
 
 if (Electron.app) {
     Electron.app.whenReady().then(async () => {
-        // Start the server
         let port = 8001 + Math.floor(Math.random() * 999);
         await new Promise(resolve => {
             srv.listen(port, () => {
-                console.log(`App server listening on port ${port}`)
+                console.log(`App server listening on port ${port}`);
                 resolve();
             });
         });
-        // Open the window
         const window = new Electron.BrowserWindow({
             width: 1100,
             height: 720,
@@ -786,8 +726,6 @@ if (Electron.app) {
             minHeight: 200
         });
         window.loadURL(`http://localhost:${port}`);
-        // Quit the app when all windows are closed
-        // unless we're on macOS
         Electron.app.on('window-all-closed', () => {
             if (process.platform !== 'darwin') Electron.app.quit();
         });