[NextJS] It does not work on the client. The "if (typeof fetch === "function")" part appears to be missing.

[n-guitar]

Expected behaviour

I would like to use "dd-tarce" in my "next" application.
At init, an error occurs and the application does not start.
I don't need the "fs api" because I don't use it.
What should I do in this case?
※ I understand that fs only works on the server side.

It appears to be slipping through the "if (typeof fetch === "function") " part.

if (typeof fetch === "function") {
    ・・・
} else {
// Node version of reading a wasm file into an array buffer.
const fs = require("fs"); // Error here
const path = require("path");

I thought the library was using "fetch" feature detection to determine if the current environment is a browser or node environment, but it doesn't appear to be working.
Is the above understanding correct?

The latest "source-map" appears to have fixed this.
mozilla/source-map#349

Actual behaviour
Steps to reproduce

import tracer from 'dd-trace';
tracer.init();

$ next dev
・・・
error - ./node_modules/@datadog/pprof/node_modules/source-map/lib/read-wasm.js:20:0
Module not found: Can't resolve 'fs'
Import trace for requested module:
./node_modules/@datadog/pprof/node_modules/source-map/lib/source-map-consumer.js
./node_modules/@datadog/pprof/node_modules/source-map/source-map.js
./node_modules/@datadog/pprof/out/src/sourcemapper/sourcemapper.js
./node_modules/@datadog/pprof/out/src/index.js
./node_modules/dd-trace/packages/dd-trace/src/profiling/profiler.js
./node_modules/dd-trace/packages/dd-trace/src/profiling/index.js
./node_modules/dd-trace/packages/dd-trace/src/profiler.js
./node_modules/dd-trace/packages/dd-trace/src/proxy.js
./node_modules/dd-trace/packages/dd-trace/index.js
./node_modules/dd-trace/index.js
./cl-common/index.ts
./pages/_app.tsx

Environment

• Operation system:
  Red Hat Enterprise Linux release 8.2 (Ootpa)
  4.18.0-193.el8.x86_64

• Node.js version:
  node: v16.13.1

• Tracer version:
  dd-trace 2.7.1

• Relevant library versions:
  yarn: 1.22.17

[rochdev]

This library doesn't support running in the browser. I would recommend looking into our browser SDK for RUM to get visibility in the browser.