backend-validation-express

backend-validation-express

Request data validation middleware using Joi for express in backend. This middleware allows you to validate req.body, req.query, req.params, req.headers. Also return the error messages to the better format.

Installation

npm install backend-validation-express

Example

validation.js

const { validator, Joi } = require("backend-validation-express");

const bodySchema = Joi.object({
    name: Joi.string().required(),
    email: Joi.string().email().required(),
    password: Joi.string().min(8).required()
});

const querySchema = Joi.object({
    _id: Joi.string().required(),
    name: Joi.string().required(),
});

const paramsSchema = Joi.string().required();

const bodyValidator = validator({ body: bodySchema });
const queryValidator = validator({ query: querySchema });
const paramsValidator = validator({ params: paramsSchema });

module.exports = { 
    bodyValidator, 
    queryValidator, 
    paramsValidator 
};

index.js

const express = require("express");
const { paramsValidator, queryValidator, bodyValidator } = require("./validation");

const app = express();

app.use(express.json());

app.post("/user", bodyValidator, (req, res, next) => {
    // Here, req.body has been validated.

    return res.status(200).json(req.body);
});

app.get("/user", queryValidator, (req, res, next) => {
    // Here, req.query has been validated.

    return res.status(200).json(req.query);
});

app.listen(3000, () => {
    console.log("Server listening on the port 3000");
});

You can add multiple schema in single validator. Example:

validation.js

const { validator, Joi } = require("backend-validation-express");

const bodySchema = Joi.object({
    name: Joi.string().required(),
    email: Joi.string().email().required(),
    password: Joi.string().min(8).required(),
    role: Joi.string()
});

const querySchema = Joi.object({
    _id: Joi.string().required(),
    role: Joi.string().required(),
});

const commonValidator = validator({ body: bodySchema, query: querySchema });

module.exports = { commonValidator };

Error Messages Format

Error message for validating only req.body in single validator

{
    "success": false,
    "errors": {
        "body": {
            "name": "name is required",
            "email": "email is required",
            "password": "password is required"
        }
    },
    "message": "Validation Error!"
}

Error message for validating req.body & req.query in single validator

{
    "success": false,
    "errors": {
        "body": {
            "name": "name is required",
            "email": "email is required",
            "password": "password is required"
        },
        "query": {
            "_id": "_id is required",
            "role": "role is required"
        }
    },
    "message": "Validation Error!"
}