express-model-validation-middleware

A middleware library for Express request validation based on model objects

Installation -

npm install express-model-validation-middleware --save

Features

Express model validation middleware is used a middlware in express js projects to validate API requests.

• 10+ validations
• All basic validations used in API requests covered.
• All custom error messages.
• Easy to use with Javascript objects as models.
• Custom status codes for errors.

How to use?

• Create a node js an express server.
• Create an API controller.
• Create a model based on request body. And pass your defined error messages.

const User = {
    name:{
        "isString":"User name must be a string",
        "min-5":"User name must be atleat 5 characters long",
        "required":"Name is required"
    },
    email:{
        "isEmail":"Enter a valid email",
        "required":"Email is required"
    },
    password:{
        "min-6":"Password must be atleat 6 characters long",
        "max-12":"Atmost 12 character long password is allowed",
        "required":"Password is required",
        "isString":"Password must be a string"
    },
    section:{
        "required":"Section name is required"
    }
}

• Import const {validateModel} = require('express-model-validation-middleware');
• Pass validateModel as middleware in API controller with two arguments 1. the User model. 2. Status code you want in response.

app.route('/').post(validateModel(User, 400), (req,res)=>{
    res.json({message:"working"})
})

• Enter API URL on postman and send a request body. Example -

{
    "name":"Joe",
    "email":"aashutoshsoni12gmail.com",
    "password":"Test@1234"
}

• If there are no errors in request body as specified in Model, it'll execute the next function. Else, will through errors and status you passed in the middleware.
• For this example, there were errors in the request object. They are throuwn in the format below, with status code of 400 Bad request.

Response

{
  "name": [
    "User name must be atleat 5 characters long"
  ],
  "email": [
    "Enter a valid email"
  ],
  "section": [
    "Section name is required"
  ]
}

Validations

List of all the validations are as -

| Validator | Use case | | ------ | ------ | | required | Check if value is null or undefined | | isString | Validate a string | | min-10 | Set minimum length of characters, 10 being the length. Set it accordingly. | | max-50 | Set maximum length of characters, 50 being the length. Set it accordingly. | | contains-foo | Check if string has certain substring. It'll check if request string has foo present. Set it accordingly. | | isArray | Check for request field is array | | isObject | Check for request field is object | | isDate | Validates date in 03-22-2021 format | | isObject | Check for request field is object | | equals-foo | Validates requested value equals to passed value foo. Set accordingly. | | isInt | Check for an integer | | isUrl | Check for URL |

Development

Want to contribute? Great! Feel free to mail me on [email protected]. Or visit my website aashutoshsoni.herokuapp.com