Can't resolve '/Users/zzzzz/git/www/yyyyy/dist/webpack.1.__datadog-helper-file.js' - webpack output.clean

[karpiuMG]

Describe what happened

Module not found: Error: Can't resolve '/Users/zzzzz/git/www/yyyyy/dist/webpack.1.__datadog-helper-file.js' - the datadogWebpackPlugin creates this file and depends on it

When webpack's build starts — and if output.clean: true is set (which is a standard practice), webpack wipes dist/ before building, deleting the helper file

Steps to reproduce the issue:

1. set output.clean: true in webpack config
2. set datadogWebpackPlugin
   plugins: [
   datadogWebpackPlugin({
   rum: {
   enable: true,
   sourceCodeContext: {
   service: config.module.name,
   version: config.packageJsonVersion || '0.0.0',
   },
   },
   })]
3. run devServer

Expected behaviour:

datadog-helper-file.js isn't deleted when the app runs so the datadogWebpackPlugin works fine

Actual behaviour:

1. Injection plugin's compiler function runs, creates the file at dist/webpack.1.__datadog-helper-file.js via
   outputFileSync (xpack.ts:35)
2. Entry points are modified to include this file path (xpack.ts:170-171)
3. Webpack's build starts — and if output.clean: true is set, webpack wipes dist/ before building, deleting the helper file
4. Webpack's resolver then tries to find the file and fails

[yoannmoinet]

Thanks a ton for the report.
I'll be fixing this in #305