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http-cors

This middleware sets HTTP CORS headers (Access-Control-Allow-Origin, Access-Control-Allow-Headers, Access-Control-Allow-Credentials), necessary for making cross-origin requests, to the response object.

Sets headers in after and onError phases.

Install

To install this middleware you can use NPM:

npm install --save @middy/http-cors

Options

  • credentials (bool) (optional): if true, sets Access-Control-Allow-Credentials (default false)
  • headers (string) (optional): value to put in Access-Control-Allow-Headers (default: false)
  • methods (string) (optional): value to put in Access-Control-Allow-Methods (default: false)
  • getOrigin (function(incomingOrigin:string, options)) (optional): take full control of the generating the returned origin. Defaults to using the origin or origins option.
  • origin (string) (optional): origin to put in the header (default: "*")
  • origins (array) (optional): An array of allowed origins. The incoming origin is matched against the list and is returned if present.
  • exposeHeaders (string) (optional): value to put in Access-Control-Expose-Headers (default: false)
  • maxAge (string) (optional): value to put in Access-Control-Max-Age header (default: null)
  • requestHeaders (string) (optional): value to put in Access-Control-Request-Headers (default: false)
  • requestMethods (string) (optional): value to put in Access-Control-Request-Methods (default: false)
  • cacheControl (string) (optional): value to put in Cache-Control header on pre-flight (OPTIONS) requests (default: null)
import middy from '@middy/core'
import httpErrorHandler from '@middy/http-error-handler'
import cors from '@middy/http-cors'

const handler = middy((event, context) => {
throw new createError.UnprocessableEntity()
})
handler.use(httpErrorHandler())
.use(cors())

// when Lambda runs the handler...
handler({}, {}, (_, response) => {
t.is(response.headers['Access-Control-Allow-Origin'],'*')
t.deepEqual(response,{
statusCode: 422,
body: 'Unprocessable Entity'
})
})

Sample usage

import middy from '@middy/core'
import cors from '@middy/http-cors'

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

handler.use(cors())

// when Lambda runs the handler...
handler({}, {}, (_, response) => {
t.is(response.headers['Access-Control-Allow-Origin'],'*')
})