improvement

backend/database/urls.json

@@ -1,15 +1,24 @@
 [
     "cloudflare.com",
-    "postgresql.org",
-    "github.com",
-    "mozilla.org",
-    "amazon.com",
+    "example.invalid",
     "google.com",
+    "myfakewebsite123.xyz",
+    "postgresql.org",
+    "notarealdomain.test",
+    "github.com",
     "docker.com",
-    "wikipedia.org",
-    "duckduckgo.com",
-    "nodejs.org",
-    "amns.in",
+    "invalid-site-999.com",
+    "mozilla.org",
     "amazon.in",
-    "amdocs.com"
+    "thisdoesnotexistabc123.com",
+    "nodejs.org",
+    "amdocs.com",
+    "fake-company-domain.org",
+    "wikipedia.org",
+    "nonexistentdomain987654.net",
+    "duckduckgo.com",
+    "amazon.com",
+    "amns.in",
+    "missingwebsite.fake",
+    "randominvaliddomain12345.io"
 ]

backend/models/db_store_controller.js

@@ -4,6 +4,12 @@ const url_path = path.join(__dirname, "../database", "db.json");
 
 const StoreRecord = async (urlRecord) => {
   try {
+    try {
+      await fs.access(url_path);
+    } catch {
+      await fs.writeFile(url_path, "[]");
+    }
+
     const rawData = await fs.readFile(url_path, "utf8");
     const data = JSON.parse(rawData);
 

backend/web_socket_server.js

@@ -6,7 +6,6 @@ const { StoreRecord } = require("./models/db_store_controller");
 const { checkUrl } = require("./models/health_status_controller");
 
 const { init, broadcast } = require("./utils/utils");
-// const urlPath = "./database/urls.json";
 const urlPath = path.join(__dirname, "database", "urls.json");
 dotenv.config();
 
@@ -35,11 +34,17 @@ const checkAllUrl = async (Store) => {
 async function setupWebSocket(wss) {
   init(wss);
   let Store = [];
+  wss.on("connection", (ws) => {
     checkAllUrl(Store);
-  setInterval(async () => {
+  });
+
+  setInterval(
+    async () => {
       Store = [];
       checkAllUrl(Store);
-  }, 2000);
+    },
+    process.env.TIME || 60 * 1000,
+  );
 }
 
 module.exports = { setupWebSocket };

frontend/index.html

@@ -15,6 +15,7 @@
             <h1>URL HEALTH MONITOR</h1>
 
             <h4>WebSocket: <span id="websocket_status">Connecting...</span></h4>
+            <h4>Page will fetch latest update every 60 second </h4>
 
             <h4 id="status"></h4>
         </div>

frontend/scripts.js

@@ -11,7 +11,6 @@ async function init() {
     const urls = await response.json();
 
     urls.forEach((url) => {
-
       const id = url.replace(/[^a-zA-Z0-9]/g, "_");
 
       const row = document.createElement("tr");
@@ -27,7 +26,6 @@ async function init() {
 
       tbody.appendChild(row);
     });
-
   } catch (err) {
     console.error(err);
   }
@@ -45,29 +43,28 @@ const websocket_status = document.getElementById("websocket_status");
 socket.onopen = () => {
   websocket_status.textContent = "Connected";
 };
-let counter = 0
+let counter = 0;
 socket.onmessage = (event) => {
   // console.log(counter)
   const data = JSON.parse(event.data);
   if (data.type === "checking") {
-        counter = counter + 1
-        console.log(counter)
-        document.getElementById("status").textContent = "Refreshed " + counter + " Times";
+    counter = counter + 1;
+    document.getElementById("status").textContent =
+      "Refreshed " + counter + " Times";
     return;
   }
 
-
   const id = data.url.replace(/[^a-zA-Z0-9]/g, "_");
   const row = document.getElementById(id);
   if (!row) return;
 
   row.querySelector(".status").textContent = data.status;
   row.querySelector(".statusCode").textContent = data.statusCode;
-    row.querySelector(".responseTime").textContent = data.responseTime != null ? `${data.responseTime} ms` : "-";
+  row.querySelector(".responseTime").textContent =
+    data.responseTime != null ? `${data.responseTime} ms` : "-";
   row.querySelector(".error").textContent = data.error || "-";
 };
 
-
 socket.onclose = () => {
   websocket_status.textContent = "Disconnected";
 };
@@ -79,7 +76,7 @@ document.getElementById("addBtn").addEventListener("click", async () => {
   const response = await fetch("/api/url/register", {
     method: "POST",
     headers: { "Content-Type": "application/json" },
-        body: JSON.stringify({ url })
+    body: JSON.stringify({ url }),
   });
 
   if (response.ok) {

package.json

@@ -2,10 +2,9 @@
   "name": "uptime_monitor",
   "version": "1.0.0",
   "description": "A lightweight **URL Health Monitoring** application built with **Node.js, Express, WebSocket, Axios, and Docker**. The application periodically checks the health of registered URLs and updates the frontend in real time using WebSockets.",
-  "main": "app.js",
+  "main": "./backend/app.js",
   "scripts": {
-    "start": "node backend/app.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "start": "node backend/app.js"
   },
   "keywords": [],
   "author": "Akshay Vadher",