[![Build Status](https://travis-ci.org/fireflysemantics/validator.svg?branch=master)](https://travis-ci.org/fireflysemantics/validator)


864.0.2411 days ago4 years agoMinified + gzip package size for @fireflysemantics/validator in KB


Build Status




Typescript Validation Decorators and Executor. Click API for the Validation API Typedoc.

If you like the @fireflysemantics/validator API please star our Github Repository.



 * Validate Todo Entities Example
export class Todo {
  gid?: string;
  id?: string;

  public title!: string;

  public completed!: boolean;

  constructor(todo?: any) {
    if (todo) {
      Object.assign(this, todo);

const todo = new Todo({ completed: 'yup' });
const todoEntities = [todo];
const errors: EntityError[] = validateEntities(todoEntities, 'gid');




npm i -S @fireflysemantics/validator @fireflysemantics/validatorts tslib


Typedoc Documentation


The Typedoc for each decorator contains usage examples.

Use the Stackblitz Starter Demo for experimentation.

See the Tutorials and Typedoc for more detailed use API and use case examples.

import { ok } from 'assert';

import {
} from '@fireflysemantics/validator';

class GreaterThanCheck {
  firstNumber: any = null;

  secondNumber: number = 22;

const GTC = new GreaterThanCheck();
const validFirstNumber: boolean = validateProperty(GTC, 'firstNumber');
ok(!validFirstNumber, 'The firstNumber property is not valid');
const OES: ObjectErrors = validate(GTC);
const errors: ValidationError[] = OES.errors;
ok(errors.length == 2, 'There should be 2 ValidationErrors created');

In this case the validation of secondNumber depends on the first number.

We minimize validation noise by triggering validation of secondNumber only if the firstNumber is valid (@IfValid('firstNumber')).


  • Progressive validation (Only check if the date is valid if the property is non null)
  • Cross property validation (Does the start date come before the end date?)
  • Cross Property Conditional Validation with @IfValid stops cross property validation a dependent property is invalid.
  • Access to the entire ValidationContext enabling the customization of validation messages post validation
  • Executes the decorators is a predictable ordered sequence

The following decorators:

  • IfValid
  • IsAfterInstant
  • IsAlpha
  • IsAlphaNumeric
  • IsArray
  • IsArrayContainerOf
  • IsArrayIn
  • IsArrayNotEmpty
  • IsArrayNotIn
  • IsArraySizeGreaterThan
  • IsArraySizeLessThan
  • IsArrayUnique
  • IsAscii
  • IsBase64
  • IsBeforeInstant
  • IsBoolean
  • IsBooleanString
  • IsByteLength
  • IsCreditCard
  • IsCurrency
  • IsDate
  • IsDefined
  • IsDivisibleBy
  • IsEmail
  • IsEmpty
  • IsEnum
  • IsEqualTo
  • IsFQDN
  • IsFullWidth
  • IsGreaterThan
  • IsHalfWidth
  • IsHexColor
  • IsHexadecimal
  • IsIP
  • IsISBN
  • IsISIN
  • IsISODateString
  • IsInRange
  • IsInstanceOf
  • IsInt
  • IsJSON
  • IsLengthGreaterThan
  • IsLengthLessThan
  • IsLessThan
  • IsLowercase
  • IsMilitaryTime
  • IsMobilePhone
  • IsMongoID
  • IsMultibyte
  • IsNegative
  • IsNotEmpty
  • IsNotEqualTo
  • IsNotSubString
  • IsNotSuperString
  • IsNumber
  • IsNumberString
  • IsPatternMatch
  • IsPositive
  • IsSameInstant
  • IsString
  • IsSubString
  • IsSuperString
  • IsSurrogatePair
  • IsURL
  • IsUUID
  • IsUpperCase
  • IsValueIn
  • IsValueNotIn
  • IsVariableWidth

Pure Validation API

For the API used to implement the decorators or for pure functions that validate see @fireflysemantics/validatorts.


This assumes a minimum ES2017 runtime environment. Use core.js if you think the code will run in non compliant runtimes. We use Object.values, which has an ES2017 a minimum runtime.


Run npm run c to build the project. The build artifacts will be stored in the dist/ directory.


After building your library with npm run p

Running unit tests

Run npm t to execute the unit tests via Jest.

Supported Package Formats

The library is built with the Angular Package Format. It therefore supports all these package formats (As can be seen in the provided package.json) and has integrated typescript definitions:

  • "main": "bundles/fireflysemantics-validatorts.umd.js",
  • "module": "fesm5/fireflysemantics-validatorts.js",
  • "es2015": "fesm2015/fireflysemantics-validatorts.js",
  • "esm5": "esm5/fireflysemantics-validatorts.js",
  • "esm2015": "esm2015/fireflysemantics-validatorts.js",
  • "fesm5": "fesm5/fireflysemantics-validatorts.js",
  • "fesm2015": "fesm2015/fireflysemantics-validatorts.js",
  • "typings": "fireflysemantics-validatorts.d.ts"

If you find any bugs or have a feature request, please open an issue on github!

The npm package download data comes from npm's download counts api and package details come from npms.io.