Request Validation

1import { z } from "zod";
2 
3// Define schemas with Zod
4const UserSchema = z.object({
5  name: z.string().min(2).max(50),
6  email: z.string().email(),
7  age: z.number().int().min(0).max(150).optional(),
8  role: z.enum(["user", "admin", "moderator"]).default("user"),
9});
10 
11const CreatePostSchema = z.object({
12  title: z.string().min(1).max(200),
13  content: z.string().min(10),
14  tags: z.array(z.string()).max(5).optional(),
15  published: z.boolean().default(false),
16});
17 
18// Infer TypeScript types from schemas
19type User = z.infer<typeof UserSchema>;
20type CreatePost = z.infer<typeof CreatePostSchema>;
21 
22// Validation function with error handling
23function validate<T>(
24  schema: z.ZodSchema<T>,
25  data: unknown
26): { success: true; data: T } | { success: false; errors: string[] } {
27  const result = schema.safeParse(data);
28 
29  if (result.success) {
30    return { success: true, data: result.data };
31  }
32 
33  const errors = result.error.errors.map(
34    (err) => `${err.path.join(".")}: ${err.message}`
35  );
36 
37  return { success: false, errors };
38}
39 
40// Example validation
41const validUser = {
42  name: "Alice",
43  email: "alice@example.com",
44  age: 25,
45};
46 
47const invalidUser = {
48  name: "A",
49  email: "not-an-email",
50  age: -5,
51};
52 
53console.log("Valid user:", validate(UserSchema, validUser));
54// { success: true, data: { name: "Alice", email: "...", age: 25, role: "user" } }
55 
56console.log("Invalid user:", validate(UserSchema, invalidUser));
57// { success: false, errors: [...] }
58 
59// Custom validators
60const PasswordSchema = z.string()
61  .min(8, "Password must be at least 8 characters")
62  .regex(/[A-Z]/, "Password must contain an uppercase letter")
63  .regex(/[a-z]/, "Password must contain a lowercase letter")
64  .regex(/[0-9]/, "Password must contain a number");
65 
66const RegisterSchema = z.object({
67  username: z.string().min(3).max(20).regex(/^[a-zA-Z0-9_]+$/),
68  email: z.string().email(),
69  password: PasswordSchema,
70  confirmPassword: z.string(),
71}).refine((data) => data.password === data.confirmPassword, {
72  message: "Passwords don't match",
73  path: ["confirmPassword"],
74});
75 
76// Test password validation
77const registration = {
78  username: "alice123",
79  email: "alice@example.com",
80  password: "SecurePass1",
81  confirmPassword: "SecurePass1",
82};
83 
84console.log("Registration:", validate(RegisterSchema, registration));