Webpack is using cjs files instead of esm

[seanparmelee]

For context, I'm using NextJS and following the instructions here to instrument the @splunk/otel-web package. While using @next/bundle-analyzer, I noticed that the @splunk/otel-web/dist/cjs files are being pulled in. I was hoping to see the @splunk/otel-web/dist/esm files being used so that Webpack can tree shake off the modules that @splunk/otel-web is not using.

It looks like the reason the CJS files are being used is because Webpack checks the browser field of the package.json first by default and currently it contains:

  "browser": "dist/cjs/index.js",
  "module": "dist/esm/index.js",

I was wondering if the team would be open to:

• updating the browser field to point to dist/esm/index.js
• renaming browser to main
• perhaps one of the solutions discussed in browser vs module fields in package.json webpack/webpack#4674
• something else?

I'm happy to open a PR.

[jtmal-signalfx]

We talked about this offline, but I still think we want to fix this issue. I'll add it to our internal backlog.