Form data validator for web application or API

Inspired from Laravel validation.

Dependency free.

If you're building application with ExpressJs and MongoDB then this is definitely something you need to check out. This is a validation tool that you can use in your every day life as The following is also applicable to the whole javascript ecosystem in general

NPM

Summary

• Installation
• Validation rules
• Usage on CommonJS
• Usage with VueJS
• Usage with Express/MongoDB
  • with repository pattern
• Hooks
• TODO
• Contribute

Installation

// with yarn
yarn add @bcdbuddy/validator

// with npm
npm install @bcdbuddy/validator

// typings: This package comes with its own typings so you won't need to install @types/...

Validation rules

• required
• email
• confirmed
• unique
• exists
• required_unless
• required_with
• in_array
• boolean

Numeric

• greater_than
• lesser_than
• min
• max
• between

Date

• date
• after
• regex

String

• min_length
• max_length
• between_length

Usage on CommonJS

const Validator = require('@bcdbuddy/validator')
const v = await Validator.make({
  data: {
    name: 'John Doe',
    age: 20,
    email: 'john at domain dot com'
    
  },
  rules: {
    name: 'required',
    age: 'min:18',
    email: 'required|email'
  }
})
if (v.fails()) {
  const errors = v.getErrors()
  // {
  //  "email": "'john at domain dot com' is not a valid email"
  // } 
}

Usage with VueJS

// component.vue => template
<template lang="pug">
  .register-page
    h1 Créer votre compte
    form.form(action="/user" method='POST' @submit.prevent="onSubmit")
      .form-field
        label(for="phone_number") Phone number 
        input(type="text" name="phone_number" id="phone_number" v-model="user.phone_number")
      .form-field
        label(for="password") Password
        input(type="password" name="password" id="password" v-model="user.password")
      .form-field
        label(for="password_confirmation") Password confirmation
        input(type="password" name="password_confirmation" id="password_confirmation" v-model="user.password_confirmation")
      .form-actions
        button.button(type="submit") Register
      p
        a(href="/user/login") Already a member ? Login here
</template>

// component.vue => script
import Validator from '@bcdbuddy/validator'
export default {
  data () {
    return {
      user: {
        phone_number: '',
        password: '',
        password_confirmation: '',
      }
    }
  },
  methods: {
    async onSubmit () {
      const v = await Validator.make({
        data: this.user,
        rules: {
            phone_number: 'required|regex:^[0-9]{9,10}$',
            password: 'required|confirmed' 
        },
      })
      if (v.fails()) {
        this.errors = v.getErrors()
        return
      }
      // your axios request here
    }
  }
}

Usage with express

import Validator from '@bcdbuddy/validator'

const formData = request.body // {first_name, last_name, age}
const v = await Validator.make({
  data: formData,
  rules: {
   note: 'greater_than:10',
   age: function (age) { // 'greater_than:18'
     return new Promise((resolve, reject) => {
       if (age < 18) {
         reject(new Error('Come back next year young blood'))
       } else {
         resolve()
       }  
     })
   },
    first_name: 'required|min:3',
    email: ['required', 'unique:Users'],
    email: function (filter) {
        const email = filter.value        
        if (!value) {
            return Promise.reject(new Error('Email is required'))
        }
        const exists = users.findIndex(user => user.email === value) !== -1
        if (exists) {
            // return Promise.resolve(false) // will know there is an error but will not use your custom error like the line below
            return Promise.reject(new Error(`Email ${value} already exists`))
        }
        return Promise.resolve(true)
    }
  },
  models: {
    Users: {
        exists (filter) {
            const value = filter.email 
            return users.findIndex(user => user.email === value) !== -1
        }
    }
  }
)

Usage with MongoDB ?

  // Your mongo model
  import Restaurants from './model/Restaurants'
  // await because contains async codes
  const v = await Validator.make({
    data: request.body,
    rules: {
      name: 'required',
      price: 'greater_than:0',
      restaurant: 'required|exists:Restaurants'
    },
    models: {
      Restaurants: {
        exists (filters) {
          return new Promise((resolve, reject) => {
            Restaurant.find(filters)
            .then(restaurants => resolve(restaurants.length > 0))
            .catch(error => reject(error))
          })
        }
      }
    }
  })

With repository pattern

If you're implementing the repository pattern then you will most likely have something like this

  // Your mongo model
  import Restaurant from './model/Restaurant'
  class RestaurantRepository {
    // ... 
    static exists (filters) {
      return new Promise((resolve, reject) => {
        Restaurant.find(filters)
        .then(restaurants => resolve(restaurants.length > 0))
        .catch(error => reject(error))
      })
    }
  }

  import RestaurantRepository from './model/RestaurantRepository'
  // await because contains async codes
  const v = await Validator.make({
    data: requrest.body,
    rules: {
      name: 'required',
      price: 'greater_than:0',
      restaurant: 'required|exists:Restaurants'
    },
    models: {
      Restaurants: RestaurantRepository
    }
  })

I also wrote about the repository pattern: [insert:devto link]

Hooks

• after validation

const v = Validator.make({
    data: {login: '', password: 's€cr€t'},
    rules: { 
        login: 'required',
        password: 'required'
    }
}
v.afterHook((validator) => {
    validator.addError('auth', 'Something is wrong with your credentials input')
})
if (v.fails()) {
    const errors = v.getErrors()
    // would contain
    // {
    //    login: 'Login field is required',
    //    auth: 'something is wrong with your credentials input'
    // }
}

TODO

• support customer message like

const message = { email: { required: 'Your email is required if you wish like to use this app' } }

• make it work with commonJS by transpiling (babel or something)
• implement rules from https://github.com/laravel/docs/blob/7.x/validation.md#available-validation-rules

Contribute

Feel free to fork, use and contribute as you want.