@novice1/validator-joi

joi validator to use with @novice1/routing.

It provides a middleware that can validate req.params, req.body, req.query, req.headers, req.cookies and req.files against a schema using joi validation.

Installation

npm install @novice1/validator-joi
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Usage

Set validator

// router.ts

import routing from '@novice1/routing'
import { validatorJoi } from '@novice1/validator-joi'

export default const router = routing()

router.setValidators(
  validatorJoi(
    // Joi.AsyncValidationOptions
    { stripUnknown: true },
    // middleware in case validation fails
    function onerror(err, req, res, next) {
      res.status(400).json(err)
    }
    // name of the property containing the schema
    'schema'
  )
)
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Create schema

// schema.ts

import Joi from 'joi'
import { ValidatorJoiSchema } from '@novice1/validator-joi'
import router from './router'

// schema for "req.body"
const bodySchema = Joi.object({
  name: Joi.string().required()
}).required()

export const routeSchema: ValidatorJoiSchema = Joi.object().keys({
    body: bodySchema
})

// or
/*
export const routeSchema: ValidatorJoiSchema = {
    body: bodySchema
}
*/

// or
/*
export const routeSchema: ValidatorJoiSchema = {
    body: {                
       name: Joi.string().required()
    }
}
*/
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Create route

import routing from '@novice1/routing'
import express from 'express'
import router from './router'
import { routeSchema } from './schema'

router.post(
  {
    name: 'Post item',
    path: '/items',

    parameters: {
        // the schema to validate
        schema: routeSchema
    },

    // body parser
    preValidators: express.json()
  },
  function (req: routing.Request<unknown, { name: string }, { name: string }>, res) {
    res.json({ name: req.body.name })
  }
)
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Transformations

Data can be transformed with methods like Joi.string().trim() and more.

req.query being readonly, its tranformed values can be retrieved from req.validated().query.

For req.params, req.body, req.headers, req.cookies and req.files, the tranformation is applied on them and req.validated() can still be used if you prefer.

/**
 * Since express@5 and @novice1/routing@2, req.query is readonly. 
 * The parsed and validated result can be found by calling the function 'req.validated()'.
 */
router.get(
  {
    name: 'Main app',
    path: '/app',
    parameters: {
      query: {
        version: Joi.number()
      }
    }
  },
  function (req, res) {
    res.json(req.validated?.<{ version?: number }>().query?.version)
  }
)
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Overrides

Override the error handler for a route.

import routing from '@novice1/routing'
import router from './router'

const onerror: routing.ErrorRequestHandler = (err, req, res) => {
  res.status(400).json(err)
}

router.get(
  {
    path: '/override',
    parameters: {
      // overrides
      onerror

    },
  },
  function (req, res) {
    // ...
  }
)
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References

• joi
• @novice1/routing