README.md

es-validation

A set of constraint validation decorators inspired by JSR-303, JSR-349 and JSR-380.

• Introduction
• Getting Started
• Decorators
• Validation
  • Validator
  • Date Provider
• Development

Introduction

The library makes it possible to:

• define constraints on properties
• define constraints on parameters
• define constraints on returned values

For a complete description, refer to the documentation.

A sample project is also available.

Getting Started

The modules can be installed using npm:

npm install @es-validation/decorators @es-validation/validator --save

Or using yarn:

yarn add @es-validation/decorators @es-validation/validator

Decorators

A number of decorators are available, and can be used on properties, parameters or functions. In the later case, the constraint applies to the returned values.

Name	Boolean	Number	String	Date	Container	Object	Description
@Constraint	✔️	✔️	✔️	✔️	✔️	✔️	Must comply to an arbitrary user-defined constraint.
@Defined	✔️	✔️	✔️	✔️	✔️	✔️	Must not be undefined.
@ElementConstraint	❌	❌	❌	❌	✔️	❌	List constraints applied to container elements.
@Undefined	✔️	✔️	✔️	✔️	✔️	✔️	Must be undefined.
@NotNull	✔️	✔️	✔️	✔️	✔️	✔️	Must not be null.
@Null	✔️	✔️	✔️	✔️	✔️	✔️	Must be null.
@True	✔️	❌	❌	❌	❌	❌	Must be true.
@False	✔️	❌	❌	❌	❌	❌	Must be false.
@NotBlank	❌	❌	✔️	❌	❌	❌	Must contain at least one non-space character.
@NotEmpty	❌	❌	✔️	❌	✔️	❌	Must not be empty.
@Size()	❌	❌	✔️	❌	✔️	❌	Must be within a size range.
@Pattern()	❌	❌	✔️	❌	❌	❌	Must match a regular expression.
@Max()	❌	✔️	✔️¹	❌	❌	❌	Must be a number that is lower than or equal to a maximum.
@Min()	❌	✔️	✔️¹	❌	❌	❌	Must be a number that is higher than or equal to a minimum.
@PositiveOrZero	❌	✔️	✔️¹	❌	❌	❌	Must be a number that is higher than or equal to 0.
@Positive	❌	✔️	✔️¹	❌	❌	❌	Must be a number that is higher than 0.
@NegativeOrZero	❌	✔️	️ ✔️¹	❌	❌	❌	Must be a number that is lower than or equal to 0.
@Negative	❌	✔️	✔️¹	❌	❌	❌	Must be a number that is lower than 0.
@Digits()	❌	✔️	✔️¹	❌	❌	❌	Must be a number with limited integral and fractional digits.
@FutureOrPresent	❌	❌	✔️²	✔️	❌	❌	Must be a date set in the future or now.
@Future	❌	❌	✔️²	✔️	❌	❌	Must be a date set in the future.
@PastOrPresent	❌	❌	✔️²	✔️	❌	❌	Must be a date set in the past or now.
@Past	❌	❌	✔️²	✔️	❌	❌	Must be a date set in the past.
@Email	❌	❌	✔️	❌	❌	❌	Must be a valid email address.
@Valid	❌	❌	❌	❌	✔️	✔️	Properties must be validated.

¹ Strings are validated as base-10 numbers when the validator is configured with stringAsNumber (disabled by default)

² Strings are validated as ISO-8601 datetimes when the validator is configured with stringAsDate (disabled by default)

Validation

The @es-validation/validator module provides validation based on the @es-validation/decorators decorators.

Validator

The Validator class is used to perform constraint validation. The following validation methods are available:

Method	Description
validate()	Validate an object's properties.
validateProperty()	Validate a specific object property.
validateValue()	Validate a value.
validateParameters()	Validate a function call's parameters.
validateReturnValue()	Validate a function call's return value.

Date Provider

The DateProvider interface is used to retrieve the current time, which is necessary for various decorators (@Past, @Future, etc.). It contains a single method:

Method	Description
getDate()	Get the current time.

There is generally no interaction with this interface from user code, unless new custom decorators dealing with time are defined. In this scenario, the DateProvider instance can be obtained through ConstraintValidationContext's getDateProvider() method.

Development

The project requires lerna and yarn to be available globally.

Bootstrap the project:

yarn bootstrap

Build the project:

yarn build

Execute all tests:

yarn test