modern-express-joi

An express.js middleware makes a powerful validation request with the Joi validation.

Inspiration

express-validator and Joi validation

Usage

• npm install modern-express-joi
• import modernValidator from 'modern-express-joi' or require('modern-express-joi').default
• make an express middleware from passing schemas to modernValidator
• add middleware to express
• call req.checkAny for validating
• call req.sanitizeAny for sanitizing

req.checkAny(String, [option])

Passing first params as string to select schema template. You can pass option as string for deep checking field by key name.

Here are available commands.

• req.checkBody for validation req.body.
• req.checkQuery for validation req.query.
• req.checkParams for validation req.params.
• req.checkHeaders coming soon
• req.checkCookies coming soon

req.sanitizeAny(String)

This is similar to req.checkAny about passing params, but it converts the target object such as req.body, req.query, req.params etc to defining format in schemaTemplates.

modernValidator(Object, [option])

Passing schemaTemplates as object that has key name of your schema templates to construct an express middleware. The second optional parameter must be an object that contains functions, and key names are only errorFormatter, customValidator, or customSanitizer.

Example Passing Parameters

modernValidator(schemaTemplates, {
  errorFormatter: (errors) => {},
  customValidator: (value) => {},
  customSanitizer: (value) => {}
})

errorFormatter(errors)

A function that receives errors array or false for formatting errors when using req.validationErrors().

customValidator(value)

A function that validates the received value then returns error array or false.

customSanitizer(value, schema)

A function that recieves value and schema then returns formatting value follows by schema.

req.validationErrors()

Getting your result of validation after you called req.checkAny. It returns false if it has no validation errors, but It returns error array in otherwise.

Example Simple Validation

// examples/simple-validation.js
import modernValidator from 'modern-express-joi'
import Joi from 'joi'
import express from 'express'
import bodyParser from 'body-parser'
const app = express()
app.use(bodyParser.json())
 
const template = Joi.object().keys({
  name: Joi.string().required(),
  age: Joi.number().positive().optional()
})
const schemaTemplates = {
  template
}
 
app.use(modernValidator(schemaTemplates))
app.post('/users', (req, res) => {
  req.checkBody('template')
  req.sanitizeBody('template')
  const errors = req.validationErrors()
  if (errors) res.status(400).send(errors)
  else res.status(200).send({ message: 'Success' })
})
 
app.listen(8080)
console.log('Running at port 8080')
 

Passed

// Request
{
  "name": "Hello",
  "age": 18
}
 
// Response 200
{ "message": "Success" }

Failed

// Request
{
  "age": "not number"
}
 
// Response 400
[
  {
    "message": "\"name\" is required",
    "path": "name",
    "type": "any.required",
    "context": {
      "key": "name"
    }
  }
]

Example Error Formatter

// examples/error-formatter.js
import modernValidator from 'modern-express-joi'
import Joi from 'joi'
import express from 'express'
import bodyParser from 'body-parser'
const app = express()
app.use(bodyParser.json())
 
const template = Joi.object.keys({
  name: Joi.string().required(),
  age: Joi.number().positive().optional()
})
const schemaTemplates = {
  template
}
const errorFormatter = (errors) => (
  errors.map(error => error.message)
)
 
app.use(modernValidator(schemaTemplates, { errorFormatter }))
app.post('/users', (req, res) => {
  req.checkBody('template')
  req.sanitizeBody('template')
  const errors = req.validationErrors()
  if (errors) res.status(400).send(errors)
  else res.status(200).send({ message: 'Success' })
})
 
app.listen(8080)
console.log('Running at port 8080')

Example Deep Checking Field

// examples/deep-checking.js
import modernValidator from 'modern-express-joi'
import Joi from 'joi'
import express from 'express'
import bodyParser from 'body-parser'
const app = express()
app.use(bodyParser.json())
 
const schemaTemplates = {
  templateName: Joi.string().required(),
  templateAge: Joi.number().positive().optional()
}
 
app.use(modernValidator(schemaTemplates))
app.post('/users', (req, res) => {
  req.checkBody('templateName', 'name')
  req.checkBody('templateAge', 'age')
  req.sanitizeBody('templateName', 'name')
  req.sanitizeBody('templateAge', 'age')
  const errors = req.validationErrors()
  if (errors) res.status(400).send(errors)
  else res.status(200).send({ message: 'Success' })
})
 
app.listen(8080)
console.log('Running at port 8080');