@sidewinder/validator

Sidewinder Validator

Validation of Sidewinder Types

Overview

This package provides JSON schema validation for the @sidewinder/type package. It is built upon Ajv and provides additional validation support for Uint8Array as well as void used in Sidewinder Contracts.

License MIT

Contents

• Overview
• Install
• Example
• Assert
• Check
• Reference Types

Install

$ npm install @sidewinder/validation

Example

The following shows general usual

import { Validator } from '@sidewinder/validation'
import { Type } from '@sidewinder/type'

const T = Type.Object({
  a: Type.String(),
  b: Type.Number(),
  c: Type.Boolean(),
  d: Type.Uint8Array(),
  e: Type.Void(),
})

const validator = new Validator(T)

validator.assert({
  a: 'foo',
  b: 1,
  c: true,
  d: new Uint8Array(),
  e: null,
})

Assert

The assert function will check the given data and throws with a ValidatorError if the data fails to check.

import { Validator, ValidatorError } from '@sidewinder/validation'

const validator = new Validator(T)

try {
  validator.assert({
    a: 'foo',
    b: 1,
    c: true,
    d: new Uint8Array(),
    e: null,
  })
} catch (error) {
  if (error instanceof ValidatorError) {
    console.log(error.errors)
    console.log(error.message)
  }
}

Check

The check function will check the given data and return a ValidatorResult object containing the result of the validation. This can be used to test the value without throwing.

import { Validator, ValidatorResult } from '@sidewinder/validation'

const validator = new Validator(T)

const result: ValidationResult = validator.check({
  a: 'foo',
  b: 1,
  c: true,
  d: new Uint8Array(),
  e: null,
})

if (!result.success) {
  console.log(result.errors)
  console.log(result.message)
}

Referenced Types

Sidewinder Validation supports schema referencing by appending the internal AJV schema compiler with additional schemas. Internally it maintains a singleton validation context that can be appended with additional schemas which allow the compiler to reference in downstream types. Because the compiler is singleton, each schema MUST have a unique $id across the entire application.

import { Compiler, Validator } from '@sidewinder/validation'

// -------------------------------------------------------------------
// Referenceable Schema
// -------------------------------------------------------------------

const T = Type.Object(
  {
    a: Type.String(),
    b: Type.Number(),
    c: Type.Boolean(),
    d: Type.Uint8Array(),
    e: Type.Void(),
  },
  { $id: 'T' },
) // must be unique

Compiler.addSchema(T)

// -------------------------------------------------------------------
// Referenced Type
// -------------------------------------------------------------------

const R = Type.Ref(T)

const validator = new Validator(R)

// -------------------------------------------------------------------
// Check
// -------------------------------------------------------------------

const result = validator.check({
  a: 'foo',
  b: 1,
  c: true,
  d: new Uint8Array(),
  e: null,
})