@grpc/proto-loader and readFileSync fails to load files in Vercel/Netlify

[Richard87]

Hi!

I'm struggling with including files in my api functions. Specifically I want to include proto files, but everything is failing now...

All code works flawless when running next dev, but failing on Vercel and on Netlify, also when running netlify dev

All code is here: https://github.com/richard87/protoloader

I have created a simple reproduction of the error, and deployed it at Vercel and Netlify to test:
https://protoloader.vercel.app/api/json / https://protoloader.vercel.app/api/grpc
https://protoloader-test.netlify.app/api/json / https://protoloader-test.netlify.app/api/grpc

This is my grpc.js api function:

const protoLoader = require('@grpc/proto-loader');

const grpcOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true
};

const protoFile = "test.proto";

export const config = {
  unstable_includeFiles: ['test.proto'],
};

export default function handler(req, res) {
  const packageDefinition = protoLoader.loadSync( protoFile, grpcOptions);
  res.status(200).json(packageDefinition)
}

And my vercel.json file:

{
  "functions": {
    "api/json.js": {
      "includeFiles": "test.json"
    },
    "api/grpc.js": {
      "includeFiles": "test.proto"
    }
  }
}

With the error log:

Vercel:
2021-11-07T19:43:37.835Z	dd740350-1ac3-43c1-819b-cfcfe848babc	ERROR
	Error: ENOENT: no such file or directory, open 'test.proto' 
   at Object.openSync (fs.js:498:3)
    at Object.readFileSync (fs.js:394:35)
    at fetch (/var/task/node_modules/protobufjs/src/root.js:172:34) 
   at Root.load (/var/task/node_modules/protobufjs/src/root.js:206:13) 
   at Root.loadSync (/var/task/node_modules/protobufjs/src/root.js:247:17)
    at Object.loadProtosWithOptionsSync (/var/task/node_modules/@grpc/proto-loader/build/src/util.js:66:29)
    at Object.loadSync (/var/task/node_modules/@grpc/proto-loader/build/src/index.js:194:31)
    at handler (/var/task/.next/server/pages/api/grpc.js:38:43)
    at Object.apiResolver (/var/task/node_modules/next/dist/server/api-utils.js:102:15)
    at processTicksAndRejections (internal/process/task_queues.js:95:5)

 {  errno: -2,  syscall: 'open',  code: 'ENOENT',  path: 'test.proto'}

Netlify:
{
  "errorType": "Runtime.UnhandledPromiseRejection",
  "errorMessage": "Error: ENOENT: no such file or directory, open 'test.proto'",
  "trace": [
    "Runtime.UnhandledPromiseRejection: Error: ENOENT: no such file or directory, open 'test.proto'",
    "    at process.<anonymous> (/var/runtime/index.js:35:15)",
    "    at process.emit (events.js:314:20)",
    "    at processPromiseRejections (internal/process/promises.js:209:33)",
    "    at processTicksAndRejections (internal/process/task_queues.js:98:32)"
  ]
}

I have looked at clues for a solution in
#194
vercel/next.js#8251

Extra:
Adding this netlify.toml solved the issue on Netlify, but the problem still persists on Vercel

[functions]
  # Includes all Markdown files inside the "files/" directory.
  included_files = ["test.json", "test.proto"]

[styfle]

I think that unstable_includeFiles isn't used for Next.js APIs yet, only Pages. cc @ijjk

The easiest way to get nft to include a file is to read it like this:

import { readFileSync } from 'fs'
import { join } from 'path'

const file = readFileSync(join(process.cwd(), 'test.proto'));

[styfle]

This will fix it Richard87/protoloader#1