Validazione a runtime con Zod

Benvenuto

Installare Zod

npm install zod

Schema di base

import { z } from 'zod';
const UserSchema = z.object({
  id: z.number(),
  name: z.string(),
  email: z.string().email(),
});
type User = z.infer<typeof UserSchema>;

Analizzare i dati

const user = UserSchema.parse({ id: 1, name: 'Alice', email: 'a@b.com' });
// user is typed as User

Analisi sicura

const result = UserSchema.safeParse(unknownData);
if (result.success) {
  console.log(result.data); // User
} else {
  console.log(result.error.issues);
}

Schemi per array e oggetti

const UsersSchema = z.array(UserSchema);
const CreateUserSchema = UserSchema.omit({ id: true });

Opzionale e nullable

const Schema = z.object({
  name: z.string(),
  bio: z.string().optional(),   // string | undefined
  avatar: z.string().nullable(), // string | null
});

Enum e union

const StatusSchema = z.enum(['active', 'inactive', 'banned']);
const InputSchema = z.string().or(z.number());

Trasformare i dati

const PriceSchema = z.string().transform(s => parseFloat(s));

Zod nelle route API

app.post('/users', async (req, res) => {
  const result = CreateUserSchema.safeParse(req.body);
  if (!result.success) return res.status(400).json(result.error);
  const user = await db.create(result.data); // typed!
  res.json(user);
});

Validatori personalizzati

const PasswordSchema = z.string().min(8).refine(
  s => /[A-Z]/.test(s), { message: 'Need uppercase' }
);

Verifica rapida

Riepilogo