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@middy/validator

@middy/validator

v3.1.1

Validator middleware for the middy framework

npm install @middy/validator

README

Middy validator middleware

Middy logo

Validator middleware for the middy framework, the stylish Node.js middleware engine for AWS Lambda

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You can read the documentation at: https://middy.js.org/docs/middlewares/validator

This middleware automatically validates incoming events and outgoing responses against custom schemas defined with the JSON schema syntax.

If an incoming event fails validation a BadRequest error is raised. If an outgoing response fails validation a InternalServerError error is raised.

This middleware can be used in combination with httpErrorHandler to automatically return the right response to the user.

It can also be used in combination with httpcontentnegotiation to load localised translations for the error messages (based on the currently requested language). This feature uses internally ajv-i18n module, so reference to this module for options and more advanced use cases. By default the language used will be English (en), but you can redefine the default language by passing it in the ajvOptions options with the key defaultLanguage and specifying as value one of the supported locales.

Also, this middleware accepts an object with plugins to be applied to customize the internal ajv instance. Out-of-the-box ajv-i18n and ajv-formats are being used.

Install

To install this middleware you can use NPM:

npm install --save @middy/validator

Options

  • eventSchema (object|function) (default undefined): The JSON schema object or compiled ajv validator that will be used to validate the input (request.event) of the Lambda handler. Supports alias inputSchema
  • contextSchema (object|function) (default undefined): The JSON schema object or compiled ajv validator that will be used to validate the input (request.context) of the Lambda handler. Has additional support for typeof keyword to allow validation of "typeof":"function".
  • responseSchema (object|function) (default undefined): The JSON schema object or compiled ajv validator that will be used to validate the output (request.response) of the Lambda handler. Supports alias inputSchema
  • ajvOptions (object) (default undefined): Options to pass to ajv class constructor. Defaults are { strict: true, coerceTypes: 'array', allErrors: true, useDefaults: 'empty', messages: false, defaultLanguage: 'en' }.
  • i18nEnabled (boolean) (default true): Option to disable i18n default package.

NOTES:

  • At least one of eventSchema or responseSchema is required.
  • Important Compiling schemas on the fly will cause a 50-100ms performance hit during cold start for simple JSON Schemas. Precompiling is highly recommended.
  • Default ajv plugins used: ajv-i18n, ajv-formats, ajv-formats-draft2019
  • If you'd like to have the error details as part of the response, it will need to be handled separately. You can access them from request.error.cause, the original response can be found at request.error.response.

Sample usage

Example for input validation:

import middy from '@middy/core'
import validator from '@middy/validator'

const handler = middy((event, context) => {
  return {}
})

const schema = {
  required: ['body', 'foo'],
  properties: {
    // this will pass validation
    body: {
      type: 'string'
    },
    // this won't as it won't be in the event
    foo: {
      type: 'string'
    }
  }
}

handler.use(validator({
  inputSchema: schema
}))

// invokes the handler, note that property foo is missing
const event = {
  body: JSON.stringify({something: 'somethingelse'})
}
handler(event, {}, (err, res) => {
  t.is(err.message,'Event object failed validation')
})

Example for output validation:

import middy from '@middy/core'
import validator from '@middy/validator'

const handler = middy((event, context) => {
  return {}
})

const schema = {
  required: ['body', 'statusCode'],
  properties: {
    body: {
      type: 'object'
    },
    statusCode: {
      type: 'number'
    }
  }
}

handler.use(validator({responseSchema: schema}))

handler({}, {}, (err, response) => {
  t.not(err, null)
  t.is(err.message,'Response object failed validation')
  expect(response).not.toBe(null) // it doesn't destroy the response so it can be used by other middlewares
})

Middy documentation and examples

For more documentation and examples, refers to the main Middy monorepo on GitHub or Middy official website.

Contributing

Everyone is very welcome to contribute to this repository. Feel free to raise issues or to submit Pull Requests.

License

Licensed under MIT License. Copyright (c) 2017-2022 Luciano Mammino, will Farrell, and the Middy team.

FOSSA Status

Release Notes

3.1.1
By will Farrell • Published on August 4, 2022

What's Changed

  • Add in module to package.json files @willfarrell
  • performance improvements @willfarrell

TypeScript

Docs

New Contributors

Full Changelog: https://github.com/middyjs/middy/compare/3.1.0...3.1.1

3.1.0
By will Farrell • Published on June 21, 2022

What's Changed

New Contributors

Full Changelog: https://github.com/middyjs/middy/compare/3.0.4...3.1.0

3.0.4
By will Farrell • Published on June 4, 2022

What's Changed

New Contributors

Full Changelog: https://github.com/middyjs/middy/compare/3.0.3...3.0.4

3.0.3
By will Farrell • Published on May 17, 2022

What's Changed

New Contributors

Full Changelog: https://github.com/middyjs/middy/compare/3.0.2...3.0.3

3.0.2
By will Farrell • Published on May 13, 2022

What's Changed

New Contributors

Full Changelog: https://github.com/middyjs/middy/compare/3.0.1...3.0.2

3.0.1
By will Farrell • Published on May 13, 2022

What's Changed

  • Updated dependencies

Full Changelog: https://github.com/middyjs/middy/compare/3.0.0...3.0.1

2.5.7
By will Farrell • Published on January 25, 2022

Fix publishing transpiling error in 2.5.6. Thanks to @maximepichou and @rreubenreyes for reporting.

General

License
MIT
Typescript Types
Built-in
Tree-shakeable
Yes

Popularity

GitHub Stargazers
3,033
Community Interest
2,905
Number of Forks
293

Maintenance

Commits
10/219/220250
Last Commit
Open Issues
4
Closed Issues
409
Open Pull Requests
1
Closed Pull Requests
149

Versions

Versions Released
10/219/22010
Latest Version Released
Aug 4, 2022
Current Tags
latest3.1.1
next3.1.0-rc.1

Contributors

willfarrell
willfarrell
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lmammino
lmammino
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vladgolubev
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greenkeeper[bot]
greenkeeper[bot]
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leog
leog
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theburningmonk
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munierujp
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JimiPedros
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sdomagala
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chris-heathwood-uoy
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