jsdocs, move observer

server/controllers/diagnosticController.js

@@ -1,19 +1,48 @@
 import { asyncHandler } from "../utils/errorUtils.js";
 
 const SERVICE_NAME = "diagnosticController";
-
-const obs = new PerformanceObserver((items) => {
-	const entry = items.getEntries()[0];
-	performance.clearMarks();
-});
-obs.observe({ entryTypes: ["measure"] });
+/**
+ * Diagnostic Controller
+ *
+ * Handles system diagnostic and monitoring requests including system statistics,
+ * performance metrics, and health checks.
+ *
+ * @class DiagnosticController
+ * @description Manages system diagnostics and performance monitoring
+ */
 class DiagnosticController {
+	/**
+	 * Creates an instance of DiagnosticController.
+	 *
+	 * @param {Object} dependencies - The dependencies required by the controller
+	 * @param {Object} dependencies.diagnosticService - Service for system diagnostics and monitoring
+	 */
 	constructor({ diagnosticService }) {
 		this.diagnosticService = diagnosticService;
 	}
 
+	/**
+	 * Retrieves comprehensive system statistics and performance metrics.
+	 *
+	 * @async
+	 * @function getSystemStats
+	 * @param {Object} req - Express request object
+	 * @param {Object} res - Express response object
+	 * @returns {Promise<Object>} Success response with system diagnostics data
+	 * @description Returns system performance metrics, memory usage, CPU statistics,
+	 * and other diagnostic information useful for monitoring system health.
+	 * @example
+	 * GET /diagnostics/stats
+	 * // Response includes:
+	 * // - Memory usage (heap, external, arrayBuffers)
+	 * // - CPU usage statistics
+	 * // - System uptime
+	 * // - Performance metrics
+	 * // - Database connection status
+	 * // - Active processes/connections
+	 */
 	getSystemStats = asyncHandler(
-		async (req, res, next) => {
+		async (req, res) => {
 			const diagnostics = await this.diagnosticService.getSystemStats();
 			return res.success({
 				msg: "OK",
@@ -24,4 +53,5 @@ class DiagnosticController {
 		"getSystemStats"
 	);
 }
+
 export default DiagnosticController;

server/service/business/diagnosticService.js

@@ -5,7 +5,18 @@ const SERVICE_NAME = "diagnosticService";
 
 class DiagnosticService {
 	static SERVICE_NAME = SERVICE_NAME;
-	constructor() {}
+	constructor() {
+		/**
+		 * Performance Observer for monitoring system performance metrics.
+		 * Clears performance marks after each measurement to prevent memory leaks.
+		 */
+		const obs = new PerformanceObserver((items) => {
+			// Get the first entry but we don't need to store it
+			items.getEntries()[0];
+			performance.clearMarks();
+		});
+		obs.observe({ entryTypes: ["measure"] });
+	}
 
 	getCPUUsage = async () => {
 		const startUsage = process.cpuUsage();