@ts-awesome/validate

TypeScript friendly minimalistic validation library

This library inspired by validate.js. Kudos to ansman for great work!

Key features:

• simplistic validator
• model validation
• reactive validation

Bare use

import {singe, presence, email} from "@ts-awesome/validate";

const input: string;

const result = single(input, presence(), email());

if (result !== true) {
  console.log(input, 'is invalid:', ...result);
}

Let's check a form

import {multi, presence, email, alphaNum, password} from "@ts-awesome/validate";

const input: Record<string, unknown>;

const schema = {
  username: [presence(), alphaNum()],
  email: [presence(), email()],
  password: [presence(), password()],
}

const result = multi(input, schema);

if (result !== true) {
  console.log('input is invalid:', ...result);
}

For more control over validation format please check validate utility.

Use with IoC

Single value validator

import {Container} from "inversify";
import {
  SingleValidator, 
  IValidator, 
  presence, 
  email,
  uuid,
} from "@ts-awesome/validate";

container
  .bind<IValidator<string>>(ValidatorSymbol)
  .toConstantValue(new SingleValidator(presence(), email()))
  .whenTargetNamed('email');

container
  .bind<IValidator<string>>(ValidatorSymbol)
  .toConstantValue(new SingleValidator(presence(), uuid()))
  .whenTargetNamed('uuid');

Model validator

import {Container} from "inversify";
import {
  ModelValidator, 
  IValidator, 
  presence, 
  email,
  password,
  alphaNum,
  validate
} from "@ts-awesome/validate";

class Model {
  @validate([presence(), alphaNum()])
  username!: string;
  
  @validate([presence(), email()])
  email!: string;
  
  @validate([presence(), password()])
  password!: string;
}

container
  .bind<IValidator<Model>>(ValidatorSymbolFor(Model))
  .toConstantValue(new ModelValidator(Model));

ValidateAutomate

For reactive environments there is a need for continuous validation. ValidateAutomate comes to resque.

import {ValidateAutomate, validate} from "@ts-awesome/validate";

class Model {
  @validate('Username', [presence(), alphaNum()])
  username!: string;

  @validate('E-mail', [presence(), email()])
  email!: string;

  @validate('Password', [presence(), password()])
  password!: string;
}

const automate = new ValidateAutomate(Model);

automate.values.username // current entered value
automate.errors.username // current error or undefined
automate.update.username('new value'); // update value and re-validate

// partial update and validate
automate.update({
  username: 'else',
  email: 'wrong'
});

automate.attempted // true if automate.validate() was tried
automate.valid // if currently everything is valid
automate.global // any global error

automate.set(true, 'some global error'); // set global error
automate.clear(true); // clear global error

automate.set('username', 'custom error'); // set error for username
automate.clear('username'); // clear errors for username

automate.reset(); // reset all errors and attempted

const model = automate.read(); // read model if this.validate() === true

Use with MobX

import { ValidateAutomate } from "@ts-awesome/validate"
import { makeAutoObservable, observable } from "mobx"

declare type Class<T> = new (...args: unknown[]) => T;

export class ObservableValidateAutomate<T> extends ValidateAutomate<T> {
  constructor(model: Class<T>, onInit?: () => void) {
    super(model, onInit)
    makeObservable(this, {
      _state: observable.deep,
      _errors: observable.deep,
      _attempted: observable,
      _global: observable,
      _runInAction: action,
      set: action,
      clear: action,
      reset: action,
      values: computed,
      errors: computed,
    } as never)
  }
}

Available validator factories

• alphaNum - checks if provide value has no special chars: !@#$%^&*(),.?":{}|<>]
• array - checks array, length and element constraints can be specified
• boolean - checks boolean values
• datetime - checks timestamps
• date - checks dates
• time - checks time
• email - checks email
• format - checks regex
• length - checks value.length, works on anything with length
• model - checks value to comply with model constraints
• notNull - check for !== null
• numericality - checks numbers
• password - checks passwords, also exports isStrongPassword and getPasswordComplexity utilities
• presence - checks for !== undefined
• primary - obsolete
• required - obsolete
• type - checks value type
• url - checks url
• uuid - checks uuid
• exclusion - checks against blacklist, rejects if on the list
• inclusion - checks against whitelist, accepts if on the list

Please note that validator factory return configured validator that can be used as standalone validator. Keep in mind that validator return undefined if valid or string with error.

import {numericality} from "@ts-awesome/validate";

const validator = numericality({onlyInteger: true, greaterThan: 5, even: true});
const valid = validator(7);

Custom validators

Validator is a function that follows interface.

interface Validator<T = unknown> {
  (
    value: T, // value to examine
    key: string, // attribute name where value is stored
    attributes: Readonly<Record<string, unknown>>, // all attributes
    globalOptions: Readonly<GlobalOptions>
  ): undefined | true | string | readonly string[];
}

It should return undefined or null or true if valid. It should return error as string or readonly string[].

Let's create a validator that checks if password and passwordRepeat are equal

import {Validator} from "@ts-awesome/validate";
import {isDefined, error, passoword, validate} from "@ts-awesome/validate/dist/validators/utils";

function equalTo<T>(field: keyof T): Validator<unknown> {
  return function EqualToValidator(value, key, attributes) {
    if (!isDefined(value))
      return;
    
    if (value !== attributes[field]) {
      return "must be a same as " + field;
    }
  }
}

class Model {
  @validate([presence(), password()])
  password!: string;
  
  @validate('Password Repeat', [presence(), equalTo<Model>('password')])
  passwordRepeat!: string;
}

License

May be freely distributed under the MIT license.

Copyright (c) 2022 Volodymyr Iatsyshyn and other contributors