Debugging Parcel2 bundler plugins

[imakeinterfaces]

I'm trying to add my own bundler plugin. I've followed the directions from the documentation and created a new plugin which looks something like this:

import { Bundler } from "@parcel/plugin";

export default new Bundler({  
  async bundle({ graph }) {
    // do stuff
  }
}

I'm not able to debug the process that runs the bundler initially, which is not making this any easier. In the past we would have used something like:

 bundler.on('buildStart', () => {
  // do stuff
 });

I'm assuming this is deprecated and that the async bundle function is called at buildStart. Can anyone confirm that this is the case?

[mischnic]

The bundler is executed on the main thread.

Are you sure your bundler plugin is actually the one that's being used?

[mischnic]

I have a feeling the bundler plugin doesn't do what you think it does: https://v2.parceljs.org/plugin-system/overview/#complete-list-of-plugin-types-(in-a-somewhat-correct-order)

[imakeinterfaces]

You may be correct, what I do know is that the parcel v1 version of this plugin used the bundler.on event to handle the work of injecting the env vars. You can take a look at that here: https://github.com/dailybeast/parcel-envkey-plugin/blob/master/src/index.js Is there another way to use this event?

[mischnic]

The only way to set what process.env is programmatically is via the JS api: https://v2.parceljs.org/features/parcel-api/ (there an env property)

[imakeinterfaces]

@mischnic Thank you this seems to provide what I need. Unfortunately when I use the minimal example you provided, and add

serve: {
      port: 8080,
      distDir: '../dist'
}

to this config i'm now getting an error @parcel/reporter-dev-server: Could not send success event to devserver because it does not exist. This seems to be a problem reported elsewhere unfortunately.

[imakeinterfaces]

I will add this as another discussion as it no longer relates to the title of this one.