zod

What is zod?

Zod is a TypeScript-first schema declaration and validation library. It allows developers to create complex schemas for data validation with a simple and intuitive API. Zod schemas are composable and can be used to validate data at the edge of your application, ensuring that you're working with well-structured and type-safe data.

What are zod's main functionalities?

Basic Type Validation

Validates that the input is a string.

{"const schema = zod.string(); try { schema.parse('hello world'); } catch (e) { console.error(e); }"}

Object Schema Validation

Validates that the input is an object with specific properties of certain types.

{"const userSchema = zod.object({ name: zod.string(), age: zod.number(), email: zod.string().email() }); try { userSchema.parse({ name: 'John', age: 30, email: '[e-mail]' }); } catch (e) { console.error(e); }"}

Array Validation

Validates that the input is an array of strings.

{"const stringArraySchema = zod.array(zod.string()); try { stringArraySchema.parse(['apple', 'banana']); } catch (e) { console.error(e); }"}

Complex Nested Validation

Validates nested objects with various property types.

{"const nestedSchema = zod.object({ user: zod.object({ name: zod.string(), contact: zod.object({ email: zod.string().email(), phone: zod.string() }) }) }); try { nestedSchema.parse({ user: { name: 'Jane', contact: { email: '[e-mail]', phone: '123-456-7890' } } }); } catch (e) { console.error(e); }"}

Custom Validation

Validates that a number is positive using custom validation logic.

{"const positiveNumber = zod.number().positive(); try { positiveNumber.parse(42); } catch (e) { console.error(e); }"}

Error Formatting

Formats validation errors for easier debugging and display.

{"const schema = zod.string(); try { schema.parse(42); } catch (e) { console.error(e.format()); }"}

Other packages similar to zod

joi

Joi is a powerful schema description language and data validator for JavaScript. It offers a similar API to Zod but has been around longer and is often considered more mature. Joi provides a wide range of built-in validators and is highly extensible.

yup

Yup is a JavaScript schema builder for value parsing and validation. It defines a schema with an expressive API and can be used with or without TypeScript. Yup is often used in the context of form validation, especially with libraries like Formik.

ajv

Ajv is a JSON Schema Validator. It validates data against JSON Schema (draft 06/07/2019) and is known for its performance. Unlike Zod, which is TypeScript-first, Ajv focuses on JSON Schema validation and is often used for validating data structures in RESTful APIs.

class-validator

Class-validator allows for validation of class instances based on decorators. It is tightly coupled with TypeScript and uses decorators to define validation rules, which can be more familiar to developers used to working with TypeScript classes and decorators.