asyncapi-validator

asyncapi-validator

message validator through asyncapi schema

Note: This library works with v2 of AsyncAPI Schema. Support for v1 is deprecated and will be removed in next major version.

npm i asyncapi-validator

Features

• Validate your AsyncApi Schema against AsyncApi Schema definition
• Validate your messages against your AsyncApi Schema definition
• Load your AsyncApi Schema from local file or any URL
• Supports AsyncApi in JSON and YAML format
• Supports all versions of AsyncAPI
• more coming . . .

Methods

.fromSource()

/** 
 * Load and Parse the schema from source. You only need to do this once, and then just use .validate() method for validations.
 * @param {string} path - local path or URL of schema
 * @param {Object} options - options for validation
 * @returns {Promise}
 */
fromSource(path, options)

Options

value	type		description
ignoreArray	boolean	optional	If true, then if schema is defined as an array and payload is an object, then payload will be placed inside an array before validation.
msgIdentifier	string	required with AsyncAPI v2	Name of parameter whose value will be used as "key" in .validate() method. Normally it is "name" as described in message-object. You can also use Specification Extensions

.validate()

/**
 * Method to validate the Payload against schema definition.
 * @param {string} key - required - message key
 * @param {Object} payload - required - payload of the message
 * @param {string} channel - required - name of the channel/topic (optional with AsyncAPI v1)
 * @param {string} operation - required - publish | subscribe (optional with AsyncAPI v1)
 * @returns {boolean}
 */
validate(key, payload, channel, operation)

_Note: 'channel' and 'operation' can only be used with AsyncAPI v2. Both are required with AsyncAPI v2.

Example usage,

Example Schema

asyncapi: 2.0.0

info:
  title: User Events
  version: 1.0.0

channels:
  user-events:
    description: user related events
    publish:
      message:
        name: UserDeletedMessage
        x-custom-key: UserDeleted
        payload:
          type: object
          properties:
            userEmail:
              type: string
            userId:
              type: string

const AsyncApiValidator = require('asyncapi-validator')
let va = await AsyncApiValidator.fromSource('./api.yaml', {msgIdentifier: 'x-custom-key'})

// validate 'UserDeleted' on channel 'user-events' with operation 'publish'
va.validate('UserDeleted', {
  userId: '123456789',
  userEmail: '[e-mail]',
}, 'user-events', 'publish')

In above example, "msgIdentifier" is "x-custom-key". That's why, "UserDeleted" has been use as "key" in "va.validate()"

Example usage with AsyncAPI V1 (deprecated)

const AsyncApiValidator = require('asyncapi-validator')
let va = await AsyncApiValidator.fromSource('./api.yaml')

// validate 'UserDeleted' key with payload
va.validate('UserDeleted', {
  userId: 'bd58d14f-fd3e-449c-b60c-a56548190d68',
  deletedBy: 'bd58d14f-fd3e-449c-b60c-a56548190d68',
  deletedAt: '2017-01-09T08:27:22.222Z',
})

// validate 'UserCreated' key with payload
va.validate('UserCreated', {1:1})

For these examples to work, key UserDeleted and UserCreated must be present in such way.

components:
  messages:
    UserDeleted:
              ...
              ...
    UserCreated:
              ...
              ...

Errors

Error thrown from asyncapi-validator will have these properties.

key	type	value	description
name	string	AsyncAPIValidationError	AsyncAPIValidationError
key	string		"key" of payload against which schema is validated
message	string		errorsText from AJV
errors	array		Array of errors from AJV

Error Example

{
  AsyncAPIValidationError: data.type should be equal to one of the allowed values at MessageValidator.validate (.....
  name: 'AsyncAPIValidationError',
  key: 'hello',
  errors:
    [
      { keyword: 'enum',
        dataPath: '.type',
        schemaPath: '#/properties/type/enum',
        params: [Object],
        message: 'should be equal to one of the allowed values'
      }
    ]
}