Abolish Validator

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Abolish provides a very simple API for developers to make both Sync and Async validations on javascript variables.

Unlike other validation libraries, Abolish is more focused on custom validations.

You can create your own validation library with abolish and use them in as many projects as you like.

You validate your data just the way you understand them.


Abolish can be used directly in browsers or in node.js via package managers or bundlers.

Package Managers

Using npm OR yarn

npm install abolish
# OR
yarn add abolish

After Installation, you can require or import Abolish class like so:

const { Abolish } = require("abolish");
// OR
import { Abolish } from "abolish";

Browser Setup

<script src="https://cdn.jsdelivr.net/npm/abolish/browser.min.js"></script>

<!-- Usage -->
    const { Abolish } = AbolishBrowser; // as window.AbolishBrowser

Basic Example

attemptValidate variable, Throw error when validation fails.
checkValidate variable but use Go Lang error handling style. No Error thrown.
testValidate variable, return boolean. true for pass and false for fail
validateValidate objects and use Go Lang error handling style. No Error thrown.

const { Abolish } = require("abolish");
const age = 17;

try {
    Abolish.attempt(age, "typeof:number|min:18");
} catch (e) {
    // Variable is too small. (Min. 18)
const { Abolish } = require("abolish");

const [err, age] = Abolish.check(17, "typeof:number|min:18");

if (err) {
    // Error: Variable is too small. (Min. 18)
const { Abolish } = require("abolish");

const validAge = Abolish.test(17, "typeof:number|min:18"); // `false`

if (!validAge) {
    // do something...
const { Abolish } = require("abolish");

const data = {
    name: "John Doe",
    password: "password",
    age: 17

const [err, validated] = Abolish.validate(data, {
    name: "typeof:string|minLength:2|maxLength:30",
    password: "typeof:string|minLength:10|maxLength:250",
    age: "typeof:number|min:18"

if (err) {
    // Error: Password is too short. (Min. 10 characters)

Validation rules can also be written as follows:

// String
Abolish.attempt(variable, "typeof:number|min:18");
// Object
Abolish.attempt(variable, { typeof: "number", min: 18 });
// Or Array of Strings or Objects
Abolish.attempt(variable, ["typeof:number", { min: 18 }]);

How it Works?

To fully explore abolish, you need to understand what it does behind the scenes.

Basically rules are converted to an object before validation starts. Where the keys are validator names and values are validator options. For example

// Is converted to.
// {typeof: "number", min: 18}

typeof and min are validators while number and 18 are their validation options.

Process Cycle:

  • Parse rules if not an object.
  • Reads the rules object.
  • Finds the corresponding validators using rules object keys.
  • Run the validator functions.

Sync Example

A validator function that checks if a file exists.

    name: "FileExists", // Case Sensitive.
    error: `File does not exist!`,
    validator: (file) => fs.existsSync(file)

We can run the FileExists validator like so.

Abolish.attempt("/path/to/file.png", "FileExists");
// if it passes
("/path/to/file.png"); // will be returned
// Else Error will be thrown.
("File does not exist!");

Async Example.

An async validator function that checks if an email belongs to a user.

    isAsync: true, // Must set for async validators
    name: "EmailBelongsToUser",
    validator: async (email) => {
        const user = await UserModel.findByEmail(email);
        if (!user) {
            throw new Error(`Email "${email}" does not belong to user.`);

We can run the async EmailBelongsToUser validator like so.

await Abolish.attemptAsync("[email protected]", "EmailBelongsToUser");
// if it passes
("[email protected]"); // will be returned
// Else Error will be thrown.
`Email "[email protected]" does not belong to user.`;
Last Updated:
Contributors: trapcodeio, TrapCode, trapcodeio