brave/joi

Name: joi

Owner: Brave Software

Description: Object schema validation

Created: 2015-11-18 18:14:47.0

Updated: 2017-04-26 15:40:29.0

Pushed: 2018-02-20 20:00:04.0

Homepage: null

Size: 2014

Language: JavaScript

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README

Object schema description language and validator for JavaScript objects.

Lead Maintainer: Nicolas Morel

Example

Joi = require('joi');

schema = Joi.object().keys({
username: Joi.string().alphanum().min(3).max(30).required(),
password: Joi.string().regex(/^[a-zA-Z0-9]{3,30}$/),
access_token: [Joi.string(), Joi.number()],
birthyear: Joi.number().integer().min(1900).max(2013),
email: Joi.string().email()
ith('username', 'birthyear').without('password', 'access_token');

validate({ username: 'abc', birthyear: 1994 }, schema, function (err, value) { });  // err === null -> valid

The above schema defines the following constraints:

• username
  • a required string
  • must contain only alphanumeric characters
  • at least 3 characters long but no more than 30
  • must be accompanied by birthyear
• password
  • an optional string
  • must satisfy the custom regex
  • cannot appear together with access_token
• access_token
  • an optional, unconstrained string or number
• birthyear
  • an integer between 1900 and 2013
• email
  • a valid email address string

Usage

Usage is a two steps process. First, a schema is constructed using the provided types and constraints:

schema = {
a: Joi.string()

Note that joi schema objects are immutable which means every additional rule added (e.g. .min(5)) will return a new schema object.

Then the value is validated against the schema:

validate({ a: 'a string' }, schema, function (err, value) { });

If the value is valid, null is returned, otherwise an Error object.

The schema can be a plain JavaScript object where every key is assigned a joi type, or it can be a joi type directly:

schema = Joi.string().min(10);

If the schema is a joi type, the schema.validate(value, callback) can be called directly on the type. When passing a non-type schema object, the module converts it internally to an object() type equivalent to:

schema = Joi.object().keys({
a: Joi.string()

When validating a schema:

• Keys are optional by default.
• Strings are utf-8 encoded by default.
• Rules are defined in an additive fashion and evaluated in order after whitelist and blacklist checks.

API

See the API Reference.