Zod

What is Zod?

• It is a library for runtime type checking and schema validation
• Parse data with a pre-defined schema
• TypeScript-first

Validate vs Parse

• Validate: check if data is valid
• Parse: check if data is valid and return the parsed data

TypeScript vs Zod

• TypeScript: Static type checking
• Zod: Parse at runtime

Use cases

• Parse form data before sending to the server
• Parse data before sending back out to the client
• Parse data at the API boundary before sending to the database
• Parse data in functions around your application
• Parse data from an external data source

Important parts

Basics

• Defining a schema
• Parsing data with a schema
• Infer TypeScript types from a schema
• Custom error messages
• Different data types (object, array, string, number, boolean, etc.)

Parsing

• parse
• safeParse
• strict
• passThrough

Refine

• Validate one field against another
• parseAsync

Enums

• Zod enums
• Native enums