Mock Data Schema Builder

Zod is a TypeScript-first schema validation library that lets you define the shape of your data declaratively. It infers TypeScript types from the schema (no duplication), validates at runtime, and generates helpful error messages. It's widely used in tRPC, Next.js, React Hook Form, and most modern TypeScript stacks.

With `const schema = z.object({ name: z.string() })`, you get the TypeScript type via `type User = z.infer<typeof schema>`. This means you define your schema once and get both runtime validation AND compile-time type checking from the same source — the single source of truth pattern.

Use the more specific validator whenever possible. z.string().email() validates that the string is a valid email format, z.string().url() validates URLs, z.string().uuid() validates UUIDs, z.string().min(1) prevents empty strings. More specific validators catch data quality issues earlier and generate better error messages.

A factory function creates a new object with realistic-looking data each time it's called. Pattern: `function createUser(overrides = {}) { return { id: uuid(), name: 'Alice Chen', ...overrides }; }`. You can call it as `createUser()` for a full mock or `createUser({ name: 'Bob' })` to override specific fields in tests.

The generated TypeScript types are compatible with any ORM or database layer. For Prisma, you'd typically use Zod alongside Prisma-generated types for input validation. Libraries like `zod-prisma-types` or `prisma-zod-generator` can automatically generate Zod schemas from your Prisma schema file.