[BUG] Custom transformers not working

[chky-nmnsoftware]

🐛 bug report

When importing and trying to use custom transformers, Parcel will simply refuse to build anything, resulting in a "Cannot find module 'hash'" error.

🎛 Configuration (.babelrc, package.json, cli command)

Command for starting server is: node parcel-watch.mjs --port 2004.

parcelrc:

{
    "extends": "@parcel/config-default",
    "transformers": {
        "*.ts": ["./parcel-transformer.mjs", "..."],
        "*.js": ["./parcel-transformer.mjs", "..."]
    }
}

parcel-watch.mjs:

import { Parcel } from '@parcel/core';
import path from 'path';
import { fileURLToPath } from 'url';
import open from "open";

// Required to convert the current module URL to a path
const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);

async function buildAndRetrieveHashes() {
    // Define the entry file or directory
    const entryFile = path.join(__dirname, 'src/index.html')
    const distDir = path.join(__dirname, 'dist')

    // Define the port
    const portArgIndex = process.argv.indexOf("--port")
    const port = Number.parseInt(process.argv[portArgIndex + 1])
    if (Number.isNaN(port) || portArgIndex < 0) return console.error("🚨 CUSTOM WATCHER ERROR: Port not supplied. Please provide a port using  ")

    // Initialize a new Parcel bundler
    const bundler = new Parcel({
        entries: entryFile,
        defaultConfig: '@parcel/config-default',
        mode: 'development', // 'production' or 'development'
        targets: {
            default: {
                distDir: distDir,
                publicUrl: "."
            }
        },
        serveOptions: {
            port
        },
        hmrOptions: {
            port
        },
        additionalReporters: [
            {packageName: '@parcel/reporter-cli', resolveFrom: __filename}
        ]
    })

    try {
        let opened
        // Tell the bundler to watch the project
        await bundler.watch(async (error, event) => {
            if (error) throw error

            if (event.type === "buildSuccess") {
                // Make placement ts files into JSON
                // await generateJSONFiles(distDir)
                if (!opened) await open(`http://localhost:${port}`)
                opened = true
            } else {
                console.log(event.diagnostics)
            }
        })
    } catch (error) {
        console.error('Build failed:', error);
    }
}

buildAndRetrieveHashes();

parcel-transformer.mjs:

import {Transformer} from '@parcel/plugin'

export default new Transformer({
  async transform({asset}) {
    const code = await asset.getCode()

    const lines = code.split('\n')
    let result = []
    let skipNextLine = false

    lines.forEach((line) => {
        if (skipNextLine) {
            skipNextLine = false
            return result.push('')
        }

        if (line.trim().startsWith('//removeOnCompile')) {
            skipNextLine = true
            return result.push('')
        }

        result.push(line)
    })

    asset.setCode(result.join('\n'))
    return [asset]
  }
})

🤔 Expected Behavior

Parcel should successfully compile the files and open the dev server.

😯 Current Behavior

Parcel fails to compile the code and returns the following error:

🚨 Build failed.

@parcel/core: Failed to resolve '8c5bef9247bbbdd5' from './node_modules/pixi.js/lib/environment-browser/browserExt.mjs'

  /home/user/Downloads/ParcelTest/node_modules/pixi.js/lib/environment-browser/browserExt.mjs:16:22
    15 | 
  > 16 | export { browserExt };
  >    |                      ^^
    17 | //# sourceMappingURL=browserExt.mjs.map
    18 | 

@parcel/resolver-default: Cannot find module '8c5bef9247bbbdd5'
[
  {
    message: "Failed to resolve '8c5bef9247bbbdd5' from './node\\_modules/pixi.js/lib/environment-browser/browserExt.mjs'",
    origin: '@parcel/core',
    codeFrames: [ [Object] ]
  },
  {
    message: "Cannot find module '8c5bef9247bbbdd5'",
    hints: [],
    origin: '@parcel/resolver-default'
  }
]

🔦 Context

This issue makes it impossible to write any custom bundlers. Even when using the CLI for building and the most basic form of a transformer, it still returns this errors. The following code also gives the same error:

import {Transformer} from '@parcel/plugin'

export default new Transformer({
  async transform({asset}) {
    return [asset]
  }
})

I know that it is successfully running because it outputs the code when it runs, however, it just refuses to build anything.

My ultimate goal is to make a transformer that will remove any code that follows a comment such as //removeOnCompile or something similar. Unfortunately, there is no way to ensure functionality without Parcel even compiling anything.

💻 Code Sample

https://github.com/chky-nmnsoftware/ParcelTransformerError

🌍 Your Environment

Software	Version(s)
Parcel	2.13.2
Node	20.18.0
npm	10.8.2
Operating System	Kubuntu 22.04

[mischnic]

*.{js,mjs,jsm,jsx,es6,cjs,ts,tsx,cts,mts} might work better, for unfortunate implementation specific reasons: #9038

[chky-nmnsoftware]

*.{js,mjs,jsm,jsx,es6,cjs,ts,tsx,cts,mts} might work better, for unfortunate implementation specific reasons: #9038

That seems to work. I wish it was documented, but oh well. Thank you very much for the help. Hopefully this will help any other people that end up falling victims to this.