Validation Library

Validation library for node.js

Node Input Validator is a validation library for node.js. You can also extend library to add custom rules.

Installation

npm install node-input-validator

Usage

const v = require('node-input-validator');

let r = {};   // first argument for constructor will always be blank object 
              // This empty object (i.e. r in this case) will be used in future

let validator = new v(r, {name:''}, {name:'required|minLength:5'});

validator.check().then(function (matched) {
    console.log(matched);
    console.log(validator.errors);
});

Extending

Validator.messages({
    even: 'The value of the field must be even number.',
    status: 'Invalid status'
});

Validator.extend('even', async function (field, value) {

    if( (parseInt(value) % 2) == 0 ){
        return true;
    } 
    
    this.validator.addError(field, 'even');
    return false;

});

Validator.extend('status', async function (field, value, args) {

    if( args.indexOf(value) >= 0 ){
        return true;
    }
    
    this.validator.addError(field, 'status');
    return false;

});

Extending/Overriding messages

Validator.messages({
    required: 'The :attribute field must not be empty.',
});

validator.rules.validateCustom = async (field, value)  => {
        	
    if( value === 'yes' || value === 'on' ){
        return true;
    }
    
    this.validator.addError(field, 'custom');
    return false;

};

For Koa2 Attach koa middleware

const validator = require('node-input-validator');
app.use(validator.koa());

Controller Example

let v = await ctx.validate(ctx.request.body, {
        name:'required|maxLength:50', 
        username:'required|maxLength:15',
        email:'required|email',
        password:'required'
    });


let isValid = await v.check();

if (!isValid) {
    // return validation errors
    ctx.body = v.errors;
}

Rules

You can check test cases for rules.

required
requiredIf:age,16
requiredNotIf:age,16
requiredWith:age
requiredWithout:age

accepted
The field under validation must be yes, on, 1, or true.

alpha
The field under validation must be entirely alphabetic characters.

alphaDash
The field under validation may have alpha-numeric characters, as well as dashes and underscores.

alphaNumeric
The field under validation only contains letters and numbers.

array
The field under validation must be an array.

ascii
The field under validation only contains ascii characters.

base64
The field under validation must be valid base64 encoded string.

between:1,9
The field under validation must be between provided values.

boolean
The field under validation must be 0/1, or true/false.

contains
The field under validation must contains provided seeds.

creditCard
The field under validation must be valid credit card string.

dateFormat
The field under validation must match the given date format.

digits
The field under validation only contains digits.

digitsBetween
The field under validation must be in between provided digit values.

email
The field under validation must be formatted as an e-mail address.

equals
The field under validation must be equal to given value.

in
The field under validation must exist in the given list of values.

integer
The field under validation must be an integer.

ip
The field under validation must be an IP address.

json
The field under validation must be a valid JSON string.

latLong
The field under validation must be a valid latitude-longitude coordinate.

max
The field under validation must be less than given value.

mime
The file under validation must have a MIME type corresponding to one of the listed extensions.

min
The field under validation must be greater than given value.

maxLength
The length of field under validation should be less than given value.

minLength
The length of field under validation should be greater than given value.

notIn
The field under validation must not exist in the given list of values.

numeric
The field under validation must be numeric.

regex
The field under validation must match the given regular expression.

same
The given field must match the field under validation.

size
The file field under validation must have a file size matching the given maximum value or should be between file size range.

string
The field under validation must be string.

url
The field under validation must be a valid URL.

Post Rules

There is set of rules which can be used to validate constraints of whole input, rather than validity of singular fields.

Usage

const v = require('node-input-validator');

let r = {};   // first argument for constructor will always be blank object 
              // This empty object (i.e. r in this case) will be used in future

let validator = new v(r, {name:''}, {'*': 'any:name,surname'});

validator.check().then(function (matched) {
    console.log(matched);
    console.log(validator.errors);
});

Post validator errors are returned in the * key. There is also possibility to add custom function as validator with help of addPostRule method. Function will be called in context of validator object with input as parameter.

const v = require('node-input-validator');

let r = {};   // first argument for constructor will always be blank object 
              // This empty object (i.e. r in this case) will be used in future

let v = new Validator(r, {username: 'arnold', password: 'arnold123'}, {});

v.addPostRule(async function(input) {

    if (input.password.indexOf(input.username) >= 0) {
        this.validator.addError('password', 'custom', 'Password cannot contain username'); 
    }

});

any Any of the fields must be present in input.

all All of the fields must be present in input.