flexible-validator

A light weight and flexible data validator for projects in javascript, typescript, node.js

Installation

npm i flexible-validator

Useabe

typescript examples

import { Validator } from 'flexible-validator';

const validator = new Validator({
  username: {
    required: true,
    string: true,

    minlen: [3, 'too short'],
    maxlen: [20, 'too long'],
  },
  age: {
    required: true,
    number: true,
    use: {
      'Too young': (input) => {
        return input >= 18;
      },
    },
  },
  email: {
    required: 'Please enter your email!',
    email: true,
  },
  password: {
    minlen: 6,
    maxlen: 20,
    use: {
      'must contain an uppercase letter': /[A-Z]+/,
    },
  },
});

const data = {
  // NOTE: if a vaulue is undefined and the require is NOT true, the other
  // patterns of this field will be skipt
  username: undefined,
  //username: 'ok',

  email: 'email',
  age: 10,
  password: '0000',
};

// Run all the validation patterns and output all the errors
const resultAll = validator.validateAll(data);

// Only return the first error and stop
const resultFirst = validator.validate(data);

console.log(resultAll);
console.log(resultFirst);

Methods

Note: returns null means pass the validation.

Validator.validateAll

validateAll({[key:string]:any}): null | [key: string]: string[];

Validator.validate

validate({[key:string]:any}): null | {field:string, error:string}

Pre-defined patterns

required: true | string

// Return with defualt error message
{
  required: true,
}

// Return with custom error message
{
  required: 'custom your error message here',
}

minlen: number | [number, string?]

{
  minlen: 3,
}

//
{
  minlen: [3, 'at least 3 characters']
}

maxlen: number | [number, string?]

{
  minlen: 20,
}

//
{
  minlen: [20, 'too long']
}

number: true | string

{
  number: true,
}

//
{
  number: "wrong format",
}

string: true | string

{
  string: true,
}

//
{
  string: "not a string",
}

email: true | string

{
  email: true,
}

//
{
  email: "wrong format",
}

noNull: true | string

{
  noNull: true,
}

//
{
  noNull: "Null is not allowed",
}

noEmpty: true | string

NOTE: This is only used to check empty string in this moment
TODO: Check empty object and object array later when there is array and object options

{
  noEmpty: true,
}

//
{
  noNull: "It is empty",
}