refactor: improve examples

Author: junjie-w

examples/package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "dev:handler": "node src/withHandler.js",
     "dev:middleware": "node src/withMiddleware.js",
-    "dev:custom": "node src/withCustomMiddleware.js"
+    "dev:custom-middlware": "node src/withCustomMiddleware.js"
   },
   "dependencies": {
     "express": "^4.18.2",

examples/src/withCustomMiddleware.js

@@ -4,6 +4,7 @@ import {
   UnauthorizedError,
   ForbiddenError,
   ValidationError,
+  NotFoundError,
 } from "http-error-handler";
 
 const app = express();
@@ -21,24 +22,36 @@ const requireAuth = (req, _res, next) => {
 };
 
 const validateUser = (req, _res, next) => {
-  const { email, password } = req.body;
-  if (!email || !password) {
-    throw new ValidationError("Missing required fields", {
-      email: !email ? "Email is required" : undefined,
-      password: !password ? "Password is required" : undefined,
-    });
+  const { email, username } = req.body;
+  const errors = {};
+
+  if (!email?.trim()) {
+    errors.email = "Email is required";
+  } else if (!email.includes("@")) {
+    errors.email = "Invalid email format";
   }
-  if (!email.includes("@")) {
-    throw new ValidationError("Invalid email format", {
-      email: "Must be a valid email address",
-    });
+
+  if (!username?.trim()) {
+    errors.username = "Username is required";
+  } else if (username.length < 3) {
+    errors.username = "Username must be at least 3 characters long";
   }
+
+  if (Object.keys(errors).length > 0) {
+    throw new ValidationError("Invalid user data", errors);
+  }
+
   next();
 };
 
 app.get("/users/:id", requireAuth, (req, _res, next) => {
   try {
     const { id } = req.params;
+    if (!id.match(/^\d+$/)) {
+      throw new ValidationError("Invalid user ID", {
+        id: "User ID must be numeric",
+      });
+    }
     throw new NotFoundError("User not found", { id });
   } catch (error) {
     next(error);
@@ -49,9 +62,19 @@ app.post("/users", requireAuth, validateUser, (req, res, next) => {
   try {
     const { role } = req.query;
     if (role === "admin") {
-      throw new ForbiddenError("Insufficient permissions");
+      throw new ForbiddenError("Insufficient permissions", {
+        requiredRole: "superadmin",
+        providedRole: role,
+      });
     }
-    res.status(201).json({ message: "User created" });
+    res.status(201).json({
+      message: "User created successfully",
+      user: {
+        email: req.body.email,
+        username: req.body.username,
+        role: role || "user",
+      },
+    });
   } catch (error) {
     next(error);
   }
@@ -61,11 +84,15 @@ app.use(
   errorMiddleware({
     includeStack: process.env.NODE_ENV !== "production",
     onError: async (error) => {
-      console.error(`[${new Date().toISOString()}] Error:`, error);
+      console.error(`[${new Date().toISOString()}] Error:`, {
+        type: error.constructor.name,
+        message: error.message,
+        details: error.details || {},
+      });
     },
   })
 );
 
-app.listen(3002, () => {
-  console.log("Server running on http://localhost:3002");
+app.listen(3003, () => {
+  console.log("Server running on http://localhost:3003");
 });

examples/src/withHandler.js

@@ -38,8 +38,11 @@ app.post("/products", async (req, res) => {
     const { name, price } = req.body;
     const errors = {};
 
-    if (!name) errors.name = "Name is required";
-    if (!price) errors.price = "Price is required";
+    if (!name?.trim()) errors.name = "Name is required";
+    if (typeof price !== "number" || price <= 0) {
+      errors.price = "Price must be a positive number";
+    }
+
     if (Object.keys(errors).length > 0) {
       throw new ValidationError("Invalid product data", errors);
     }
@@ -50,6 +53,6 @@ app.post("/products", async (req, res) => {
   }
 });
 
-app.listen(3000, () => {
-  console.log("Server running on http://localhost:3000");
+app.listen(3001, () => {
+  console.log("Server running on http://localhost:3001");
 });

examples/src/withMiddleware.js

@@ -8,15 +8,15 @@ import {
 const app = express();
 app.use(express.json());
 
-app.get("/with-middleware", (req, res, next) => {
+app.get("/with-middleware", (_req, _res, next) => {
   try {
     throw new NotFoundError("Resource not found");
   } catch (error) {
     next(error);
   }
 });
 
-app.get("/users/:id", (req, res, next) => {
+app.get("/users/:id", (req, _res, next) => {
   try {
     const { id } = req.params;
     if (!id.match(/^\d+$/)) {
@@ -28,6 +28,33 @@ app.get("/users/:id", (req, res, next) => {
   }
 });
 
+app.post("/users/register", (req, _res, next) => {
+  try {
+    const { email, username } = req.body;
+    const errors = {};
+
+    if (!email?.trim()) {
+      errors.email = "Email is required";
+    } else if (!email.includes("@")) {
+      errors.email = "Invalid email format";
+    }
+
+    if (!username?.trim()) {
+      errors.username = "Username is required";
+    } else if (username.length < 3) {
+      errors.username = "Username must be at least 3 characters long";
+    }
+
+    if (Object.keys(errors).length > 0) {
+      throw new ValidationError("Invalid registration data", errors);
+    }
+
+    throw new Error("Database connection failed");
+  } catch (error) {
+    next(error);
+  }
+});
+
 app.use(
   errorMiddleware({
     onError: async (error) => {
@@ -36,6 +63,6 @@ app.use(
   })
 );
 
-app.listen(3001, () => {
-  console.log("Server running on http://localhost:3001");
+app.listen(3002, () => {
+  console.log("Server running on http://localhost:3002");
 });