feat: add port availability check before starting service

src/index.ts

@@ -11,6 +11,7 @@ import {
   isServiceRunning,
   savePid,
 } from "./utils/processCheck";
+import { isPortAvailable } from "./utils/portCheck";
 import { CONFIG_FILE } from "./constants";
 import { createStream } from 'rotating-file-stream';
 import { HOME_DIR } from "./constants";
@@ -73,6 +74,17 @@ async function run(options: RunOptions = {}) {
 
   const port = config.PORT || 3456;
 
+  // Check port availability before starting the service
+  try {
+    const isAvailable = await isPortAvailable(port);
+    if (!isAvailable) {
+      console.log(`Port ${port} is already in use. Please stop the process using this port or change the PORT in your config file.`);
+      process.exit(1);
+    }
+    console.log(`Port ${port} is not in use. start process ....`);
+  } catch (error) {
+    console.log("Could not check port availability, proceeding with start...");
+  }
   // Save the PID of the background process
   savePid(process.pid);
 

src/utils/portCheck.ts

@@ -0,0 +1,46 @@
+import net from 'net';
+
+/**
+ * Check if a port is available for use
+ * @param port The port number to check
+ * @returns Promise that resolves to true if port is available, false otherwise
+ */
+export async function isPortAvailable(port: number): Promise<boolean> {
+  return new Promise((resolve) => {
+    const server = net.createServer();
+
+    server.once('error', (err: any) => {
+      if (err.code === 'EADDRINUSE') {
+        resolve(false);
+      } else {
+        // Some other error occurred
+        resolve(false);
+      }
+    });
+
+    server.once('listening', () => {
+      // Port is available, close the server
+      server.close(() => {
+        resolve(true);
+      });
+    });
+
+    server.listen(port, '127.0.0.1');
+  });
+}
+
+/**
+ * Check if a port is in use by trying to connect to it
+ * @param port The port number to check
+ * @param host The host to check (defaults to 127.0.0.1)
+ * @returns Promise that resolves to true if port is in use, false otherwise
+ */
+export async function isPortInUse(port: number, host: string = '127.0.0.1'): Promise<boolean> {
+  try {
+    const result = await isPortAvailable(port);
+    return !result;
+  } catch (error) {
+    // If there's an error checking, assume it's in use
+    return true;
+  }
+}