feat: enhance user management functionality with detailed feedback and improved error handling

backend/server.js

@@ -3,17 +3,22 @@ import express from "express";
 const app = express();
 const port = 4000;
 
+// Importing database functions for user operations
 import { loginUser, createUser, updateUser, deleteUser } from "./database.js";
 
+// Middleware to parse URL-encoded bodies (form submissions)
 app.use(express.urlencoded({ extended: true }));
+// Set EJS as the view engine for rendering templates
 app.set("view engine", "ejs");
 
 import path from "path";
 import { fileURLToPath } from "url";
 
+// Setup for __dirname and __filename in ES modules
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = path.dirname(__filename);
 
+// Start the server and listen on the specified port
 app.listen(port, () => {
   console.log(`Server is running on http://localhost:${port}`);
 });
@@ -26,18 +31,21 @@ app.use(express.static("public"));
 
 // Main code below
 
-// Route to handle GET requests to the root URL
+// Route to handle GET requests to the root URL (login page)
 app.get("/", (req, res) => {
   res.render("login.ejs", { error: null, reload: false });
   console.log("Frontend user requested frontend login page.");
 });
 
+// Variable to keep track of the latest logged-in user
 let latestUser;
 
 // Route to handle user login
 app.post("/login", (req, res) => {
+  // Attempt to log in the user with provided credentials
   loginUser(req.body.username, req.body.password).then((result) => {
     if (result.success) {
+      // On successful login, render the dashboard and update latestUser
       res.status(200).render("dashboard.ejs", {
         sqlResult: result,
         newLink: `/dashboard/${result.user.id}`,
@@ -46,6 +54,7 @@ app.post("/login", (req, res) => {
       });
       latestUser = result;
     } else {
+      // On failure, re-render login page with error message
       res
         .status(401)
         .render("login.ejs", { error: result.message, reload: true });
@@ -53,18 +62,22 @@ app.post("/login", (req, res) => {
   });
 });
 
+// Route to handle user creation, update, and deletion
 app.post(["/createUser", "/updateUser", "/deleteUser"], (req, res) => {
   let action = req.path;
   let funcName;
 
+  // Determine which database function to use based on the route
   if (action === "/createUser") {
     funcName = createUser;
   } else if (action === "/updateUser") {
     funcName = updateUser;
   } else if (action === "/deleteUser") {
+    // Prevent deleting the currently logged-in user
     if (latestUser && req.body.username !== latestUser.user.username) {
       funcName = deleteUser;
     } else {
+      // Render dashboard with alert if trying to delete logged-in user
       res.status(400).render("dashboard.ejs", {
         sqlResult: latestUser,
         newLink: latestUser ? `/dashboard/${latestUser.id}` : "#",
@@ -74,9 +87,11 @@ app.post(["/createUser", "/updateUser", "/deleteUser"], (req, res) => {
       return;
     }
   } else {
+    // Handle invalid actions
     res.status(400).send("Invalid action");
     return;
   }
+  // Call the selected database function with user data
   funcName(
     req.body.username,
     req.body.first_name,
@@ -85,6 +100,7 @@ app.post(["/createUser", "/updateUser", "/deleteUser"], (req, res) => {
     req.body.email
   ).then((result) => {
     if (result.success === true) {
+      // On success, render dashboard with success message
       res.status(201).render("dashboard.ejs", {
         sqlResult: latestUser,
         newLink: `/dashboard/${latestUser.id}`,
@@ -92,6 +108,7 @@ app.post(["/createUser", "/updateUser", "/deleteUser"], (req, res) => {
         success: "User action successful!",
       });
     } else {
+      // On failure, render dashboard with alert
       res.status(400).render("dashboard.ejs", {
         sqlResult: latestUser,
         newLink: `/dashboard/${latestUser.id}`,
@@ -104,6 +121,7 @@ app.post(["/createUser", "/updateUser", "/deleteUser"], (req, res) => {
 
 // error handling code
 app.use((err, req, res, next) => {
+  // Log the error stack and send a generic error response
   console.error(err.stack);
   res.status(500).send("Something broke!");
 });