Validation Approach
- zod:
zodis a TypeScript-first schema validation library that provides a simple and expressive API for defining schemas. It emphasizes type safety and provides excellent type inference for validated data. - joi:
joiuses a schema-based approach for validation. You define a schema for your data, andjoivalidates the data against this schema. It supports complex validation scenarios, including nested objects and arrays. - yup:
yupalso uses a schema-based approach similar tojoi, but it is designed to be more lightweight and intuitive. It is particularly well-suited for front-end applications and integrates nicely with libraries like Formik. - class-validator:
class-validatorfocuses on validation using decorators. It allows you to define validation rules directly in your class properties, making it easy to validate class instances. It does not handle data transformation. - class-transformer-validator:
class-transformer-validatorcombines validation and transformation using decorators, making it easy to validate and transform class instances simultaneously. It leverages the power ofclass-transformerto handle both tasks seamlessly.
TypeScript Support
- zod:
zodis built with TypeScript first, providing the best type inference and type safety among the listed libraries. It is designed to take full advantage of TypeScript's features. - joi:
joiprovides good TypeScript support, but its dynamic nature can sometimes make type inference challenging, especially with complex schemas. - yup:
yuphas solid TypeScript support, and its API is designed to be type-friendly, making it easy to work with in TypeScript projects. - class-validator:
class-validatoris designed with TypeScript in mind, making full use of decorators and type annotations to ensure type-safe validation of class instances. - class-transformer-validator:
class-transformer-validatorhas excellent TypeScript support, leveraging decorators and type annotations to provide type-safe validation and transformation.
Error Handling
- zod:
zodoffers structured error handling with detailed error reports that include information about the validation failures. It provides a clear and consistent way to handle errors. - joi:
joiprovides rich error handling with detailed error objects that include information about the validation failure, making it easy to understand and handle errors programmatically. - yup:
yupalso provides detailed error objects for validation failures, which include information about the failed validation and the path to the invalid value, making it easy to display errors in a user-friendly manner. - class-validator:
class-validatoroffers comprehensive error handling, returning an array of validation errors that include the property name, error message, and constraints. It allows for easy customization of error messages. - class-transformer-validator:
class-transformer-validatorprovides detailed error messages for validation failures, including information about which property failed validation and why. It also supports custom error messages.
Integration with Frameworks
- zod:
zodis gaining popularity in the React and TypeScript communities for its type-safe validation and integration with modern front-end frameworks. - joi:
joiis framework-agnostic and can be used in any JavaScript or TypeScript application. It is commonly used in Node.js applications for validating request payloads. - yup:
yupis particularly popular in React applications and works well with form libraries like Formik and React Hook Form, making it a great choice for front-end validation. - class-validator:
class-validatoris widely used in frameworks like NestJS and Angular, where class-based validation is common. It integrates seamlessly with these frameworks' dependency injection and validation systems. - class-transformer-validator:
class-transformer-validatorintegrates well with frameworks like NestJS, where you can use class-based validation and transformation in your controllers and services.
Ease of Use: Code Examples
- zod:
Example of
zodconst { z } = require('zod'); const schema = z.object({ name: z.string(), email: z.string().email(), }); schema.safeParse({ name: 'John', email: 'invalid-email' }); - joi:
Example of
joiconst Joi = require('joi'); const schema = Joi.object({ name: Joi.string().required(), email: Joi.string().email().required(), }); const { error, value } = schema.validate({ name: 'John', email: 'invalid-email' }); console.log(error); - yup:
Example of
yupconst yup = require('yup'); const schema = yup.object().shape({ name: yup.string().required(), email: yup.string().email().required(), }); schema.validate({ name: 'John', email: 'invalid-email' }).catch((err) => { console.log(err); }); - class-validator:
Example of
class-validatorimport { IsEmail, IsString } from 'class-validator'; import { validate } from 'class-validator'; import { plainToClass } from 'class-transformer'; class User { @IsString() name: string; @IsEmail() email: string; } const user = plainToClass(User, { name: 'John', email: 'invalid-email' }); const errors = await validate(user); console.log(errors); - class-transformer-validator:
Example of
class-transformer-validatorimport { IsEmail, IsString } from 'class-validator'; import { validate } from 'class-validator'; import { plainToClass } from 'class-transformer'; import { validateAndTransform } from 'class-transformer-validator'; class User { @IsString() name: string; @IsEmail() email: string; } const user = plainToClass(User, { name: 'John', email: 'invalid-email' }); const errors = await validateAndTransform(user); console.log(errors);
