Bootstrapping

[CyberT33N]

Goals

Ability to run custom Code before application starts in any environment

Background

As far as I found out the only ways to run custom code at the application start is by using Instrumentation or edit next.config.js:

const { PHASE_DEVELOPMENT_SERVER } = require('next/constants')

module.exports = async(phase, { defaultConfig }) => {
    if (phase === PHASE_DEVELOPMENT_SERVER) {
        foo()
    }

    const nextConfig = {
        experimental: {
            instrumentationHook: true
        }
    }

    return nextConfig
}

However, Instrumenation is not working with alll code e.g. when you import glob then you get an error:

/promises
Module build failed: UnhandledSchemeError: Reading from "node
/promises" is not handled by plugins (Unhandled scheme).
Webpack supports "data:" and "file:" URIs by default.
You may need an additional plugin to handle "node:" URIs.
Import trace for requested module:
node
/promises
./node_modules/path-scurry/dist/esm/index.js
./node_modules/glob/dist/esm/glob.js
./node_modules/glob/dist/esm/index.js

• This is related to the webpack transpilation

Also the next.config.js workaround is not working with typescript. Only with .js and .mjs files which you import/require then.

Would be lovely if there would be an official way to do a bootsraping.

Proposal

Please create boostrap.js/ts which will execute any custom code before the application is started

[icyJoseph]

I think, for edge env you should skip importing node: thing right? Which is used by glob -> path-scurry

Do remember that instrumentation runs for node and edge.

export async function register() {
  if (process.env.NEXT_RUNTIME === 'nodejs') {
    await import('./instrumentation-node')
  }
 
  if (process.env.NEXT_RUNTIME === 'edge') {
    await import('./instrumentation-edge')
  }
}

[icyJoseph]

Yeah but you are already importing the file. import-ing bares a cost/implicaiton that a lot of developer don't seem to really grasp.

export async function register() {
    console.log('process.env.NEXT_RUNTIME', process.env.NEXT_RUNTIME)

    if (process.env.NEXT_RUNTIME === 'nodejs') {
        const bootstrap = await import('@/src/bootstrap');
        await bootstrap();
    }
}

[CyberT33N]

Thank you now it its working <3

[icyJoseph]

Don't forget to mark as answered :)

[CyberT33N]

I set it to closed is this enough?

[icyJoseph]

Yes, choosing an answer as "the answer", helps others who might find the discussion and want to know how to fix the problem.

[CyberT33N]

Already solved. Missunderstanding