Combine with webpack-manifest-plugin

[holmey]

When combining the Plugin with the webpack-manifest-plugin the es6 Version will get generated correctly but the entry of the legacy file in the Manifest is missing.

The simplified plugin configuration to this issue looks like this:

plugins: [
  new WebpackManifestPlugin({
    basePath: paths.ASSET_DIR
  }),
  new BabelEsmPlugin({ 
    chunkFilename: 'javascripts/chunks/[chunkhash].[name].es6.js',
    filename: 'javascripts/[chunkhash].[name].es6.js'
  })
]

The main.js and the main.es6.js file will get generated but the manifest.json will just contain the URL to the es6 version and the legacy file is missing in the map of source filenames.

{
  "/main.js": "/javascripts/6aed7290bc40b110cb97.main.js",
}

Is this a configuration issue?