validation-utils

Validation utils for Javascript that provide convenient way to throw a typed error if some expected condition is not satisfied.

Node.JS 12+ is supported.

Getting started

Install the library with npm install validation-utils

const { validateNotEmpty } = require('validation-utils');

function init (email) {
  this.email = validateNotEmpty(email); //will throw an error if email is not provided
}

TypeScript

import { validateNotEmpty } from 'validation-utils';

Validators

• validateArray(entity [, errorText]) - check if entity is an array.
• validateBoolean(entity [, errorText]) - check if entity is a boolean.
• validateBooleanNonStrict(entity [, errorText]) - check if entity is a boolean or a (case-insensitive) 'true' or 'false' string.
• validateBooleanFalse(entity [, errorText]) - check if entity is a boolean with value False.
• validateBooleanTrue(entity [, errorText]) - check if entity is a boolean with value True.
• validateDate(entity [, errorText]) - check if entity is an instance of Date.
• validateEqual(entity, expectedEqualEntity [, errorText]) - check if entity is equal to the expected one (compared with ===).
• validateOneOf(entity, expectedOneOfEntities [, errorText]) - check if entity is equal to one of the expected ones (indexOf !== -1).
• validateSomeNotNil(entities [, errorText]) - check if at least one of the given entities are not null or undefined.
• validateFalsy(entity [, errorText]) - check if entity is falsy.
• validateFunction(entity [, errorText]) - check if entity is a function.
• validateInheritsFrom(entityClass, expectedParentClass [, errorText]) - check if class inherits from a given class.
• validateInstanceOf(entity, expectedClass [, errorText]) - check if entity is an instance of a given class.
• validateNotEmpty(entity [, errorText]) - check if entity is not an empty Object, String or Array.
• validateNotNil(entity [, errorText]) - check if entity is not null or undefined.
• validateNil(entity [, errorText]) - check if entity is null or undefined.
• validateNumber(entity [, errorText]) - check if entity is a number.
• validatePositiveNumber(entity [, errorText]) - check if entity is a positive number.
• validateNegativeNumber(entity [, errorText]) - check if entity is a negative number.
• validateGreaterThan(number, threshold [, errorText]) - check if entity is a number than is greater than the specified threshold.
• validateLessThan(number, threshold [, errorText]) - check if entity is a number than is less than the specified threshold.
• validateString(entity [, errorText]) - check if entity is a string.
• validateObject(entity [, errorText]) - check if entity is an object.
• validateTruthy(entity [, errorText]) - check if entity is truthy.
• validateHasProperties(entity, expectedProperties[, errorText]) - check if entity has at least a given set of properties defined.
• validateNotNilProperties(entity, expectedProperties[, errorText]) - check if none of specified properties are null or undefined for the entity.

All validators return validated value as a result.