fluent-json-schema/src/example.js

JSON Schema fluent API

'use strict'
const S = require('./FluentJSONSchema')
const Ajv = require('ajv')

const ROLES = {
  ADMIN: 'ADMIN',
  USER: 'USER'
}

const schema = S.object()
  .id('http://foo/user')
  .title('My First Fluent JSON Schema')
  .description('A simple user')
  .prop(
    'email',
    S.string()
      .format(S.FORMATS.EMAIL)
      .required()
  )
  .prop(
    'password',
    S.string()
      .minLength(8)
      .required()
  )
  .prop(
    'role',
    S.string()
      .enum(Object.values(ROLES))
      .default(ROLES.USER)
  )
  .prop(
    'birthday',
    S.raw({ type: 'string', format: 'date', formatMaximum: '2020-01-01' }) // formatMaximum is an AJV custom keywords
  )
  .definition(
    'address',
    S.object()
      .id('#address')
      .prop('line1', S.anyOf([S.string(), S.null()])) // JSON Schema nullable
      .prop('line2', S.string().raw({ nullable: true })) // Open API / Swagger  nullable
      .prop('country', S.string())
      .prop('city', S.string())
      .prop('zipcode', S.string())
      .required(['line1', 'country', 'city', 'zipcode'])
  )
  .prop('address', S.ref('#address'))

console.log(JSON.stringify(schema.valueOf(), undefined, 2))

const ajv = new Ajv({ allErrors: true })
const validate = ajv.compile(schema.valueOf())
let user = {}
let valid = validate(user)
console.log({ valid }) //= > {valid: false}
console.log(validate.errors)
/* [
  {
    keyword: 'required',
    dataPath: '',
    schemaPath: '#/required',
    params: { missingProperty: 'email' },
    message: "should have required property 'email'",
  },
  {
    keyword: 'required',
    dataPath: '',
    schemaPath: '#/required',
    params: { missingProperty: 'password' },
    message: "should have required property 'password'",
  },
] */

user = { email: 'test', password: 'password' }
valid = validate(user)
console.log({ valid }) //= > {valid: false}
console.log(validate.errors)
/*
[ { keyword: 'format',
    dataPath: '.email',
    schemaPath: '#/properties/email/format',
    params: { format: 'email' },
    message: 'should match format "email"' } ]
*/

user = { email: 'test@foo.com', password: 'password' }
valid = validate(user)
console.log({ valid }) //= > {valid: true}
console.log(validate.errors) // => null

user = { email: 'test@foo.com', password: 'password', address: { line1: '' } }
valid = validate(user)
console.log({ valid }) //= > {valid: false}
console.log(validate.errors)

/*
{ valid: false }
[ { keyword: 'required',
    dataPath: '.address',
    schemaPath: '#definitions/address/required',
    params: { missingProperty: 'country' },
    message: 'should have required property \'country\'' },
  { keyword: 'required',
    dataPath: '.address',
    schemaPath: '#definitions/address/required',
    params: { missingProperty: 'city' },
    message: 'should have required property \'city\'' },
  { keyword: 'required',
    dataPath: '.address',
    schemaPath: '#definitions/address/required',
    params: { missingProperty: 'zipcoce' },
    message: 'should have required property \'zipcode\'' } ]
*/

const userBaseSchema = S.object()
  .additionalProperties(false)
  .prop('username', S.string())
  .prop('password', S.string())

const userSchema = S.object()
  .prop('id', S.string().format('uuid'))
  .prop('createdAt', S.string().format('time'))
  .prop('updatedAt', S.string().format('time'))
  .extend(userBaseSchema)
  .valueOf()

console.log(userSchema.valueOf())