Next.js API routes (and pages) should support reading files

Feature request

Is your feature request related to a problem? Please describe.

It’s currently not possible to read files from API routes or pages.

Describe the solution you’d like

I want to be able to call fs.readFile with a __dirname path and have it “just work”.

This should work in Development and Production mode.

Describe alternatives you’ve considered

This may need to integrate with @zeit/webpack-asset-relocator-loader in some capacity. This plugin handles these types of requires.

However, it’s not a necessity. I’d be OK with something that only works with __dirname and __filename (no relative or cwd-based paths).

Additional context

Example:

// pages/api/test.js
import fs from 'fs'
import path from 'path'

export default (req, res) => {
  const fileContent = fs.readFileSync(
    path.join(__dirname, '..', '..', 'package.json'), 
    'utf8'
  )
  // ...
}

Note: I know you can cheat the above example ☝️ with require, but that’s not the point. 😄

[jkjustjoshing]

Workaround I’m using:

# next.config.js
module.exports = {
    serverRuntimeConfig: {
        PROJECT_ROOT: __dirname
    }
}

and in the location you need the path

import fs from 'fs'
import path from 'path'
import getConfig from 'next/config'
const { serverRuntimeConfig } = getConfig()

fs.readFile(path.join(serverRuntimeConfig.PROJECT_ROOT, './path/to/file.json'))

I know this doesn’t solve the need to reference files with paths relative to the current file, but this solves my very related use case (reading image files from a /public/images folder).

[borispoehland]

@bengrunfeld yes, your solution only works locally.

I had a similar problem lately (wanted to read a file in a API route) and the solution was easier than expected.

Try path.resolve('./public/ts-data.csv')