[Bug?]: Error when using Fastify Compress Plugin due to stream being closed prematurely

[dthyresson]

What's not working?

When registering the fastify/compress plugin

    await fastify.register(import('@fastify/compress'), {
      global: true,
      threshold: 1_024,
      encodings: ['deflate'],
    })

and making a request, there is an error in the compress plugin and fustily due to the stream closing prematurely:

api | 06:43:01 🐛 graphql-server GraphQL execution completed: BlogPostsQuery
api | 06:43:01 🐛 Execution end
api | 06:43:01 🌲 stream closed prematurely
api | 06:43:01 🚨 premature close 
api | 
api | 🚨 Error Info
api | 
api | {}
api |  
api | 🥞 Error Stack
api | 
api | Error: premature close
api |     at onclosenexttick (/Users/dthyresson/Dropbox/Code/throwaways/blog-compress/node_modules/end-of-stream/index.js:54:86)
api |     at processTicksAndRejections (node:internal/process/task_queues:78:11)
api | 
a

How do we reproduce the bug?

See config above.

There is discussion on Fastify about such behavior:

fastify/fastify-compress#215
fastify/fastify#3651

Fix

A fix seems to be return the reply

const fastifyResponseForLambdaResult = (
  reply: FastifyReply,
  lambdaResult: APIGatewayProxyResult
) => {
  const {
    statusCode = 200,
    headers,
    body = '',
    multiValueHeaders,
  } = lambdaResult
  const h = mergeMultiValueHeaders(headers, multiValueHeaders)
  reply.headers(h)
  reply.status(statusCode)

  if (lambdaResult.isBase64Encoded) {
    // Correctly handle base 64 encoded binary data. See
    // https://aws.amazon.com/blogs/compute/handling-binary-data-using-amazon-api-gateway-http-apis
    return reply.send(Buffer.from(body, 'base64')) // <---- add return
  } else {
    return reply.send(body) // <---- add return
  }
}

and now can see that deflate is applied as the compression:

What's your environment? (If it applies)

No response

Are you interested in working on this?

• I'm interested in working on this