`msw@2.8` breaks `npm run test:browser` in instrumentation-fetch

[trentm]

https://github.com/open-telemetry/opentelemetry-js/actions/runs/15142757414/job/42571833122?pr=5700
should npm run test:browser failing for instr-fetch for #5700.

long test output

> @opentelemetry/instrumentation-fetch:"test:browser"


> @opentelemetry/instrumentation-fetch@0.201.1 test:browser
> karma start --single-run

webpack was not included as a framework in karma configuration, setting this automatically...
karma-webpack does not currently support customized filenames via
webpack output.filename, if this is something you need consider opening an issue.
defaulting bundle.js to [name].js.
Webpack bundling...
assets by status 14.8 KiB [compared for emit]
  assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/src/ 14.3 KiB
    assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/src/*.ts 10.3 KiB 6 assets
    assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/src/*.map 3.53 KiB 6 assets
    assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/src/enums/ 491 bytes 2 assets
  assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/test/ 516 bytes
    assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/test/*.map 360 bytes 3 assets
    assets by path ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/test/*.ts 156 bytes
      asset ../../home/runner/work/opentelemetry-js/opentelemetry-js/experimental/packages/opentelemetry-instrumentation-fetch/build/test/index-webpack.d.ts 54 bytes [compared for emit]
      + 2 assets
assets by status 10.3 MiB [emitted]
  asset commons.js 10.3 MiB [emitted] (name: commons) (id hint: commons)
  asset runtime.js 7.64 KiB [emitted] (name: runtime)
  asset index-webpack.3036668705.js 1.04 KiB [emitted] (name: index-webpack.3036668705)
Entrypoint index-webpack.3036668705 10.3 MiB = runtime.js 7.64 KiB commons.js 10.3 MiB index-webpack.3036668705.js 1.04 KiB

ERROR in ../../../node_modules/@open-draft/logger/lib/index.mjs 236:4-11
Module not found: Error: Can't resolve 'process/browser' in '/home/runner/work/opentelemetry-js/opentelemetry-js/node_modules/@open-draft/logger/lib'
Did you mean 'browser.js'?
BREAKING CHANGE: The request 'process/browser' failed to resolve only because it was resolved as fully specified
(probably because the origin is strict EcmaScript Module, e. g. a module with javascript mimetype, a '*.mjs' file, or a '*.js' file where the package.json contains '"type": "module"').
The extension in the request is mandatory for it to be fully specified.
Add the extension to the request.
 @ ../../../node_modules/@mswjs/interceptors/lib/browser/chunk-QED3Q6Z2.mjs 2:0-44 31:22-28
 @ ../../../node_modules/@mswjs/interceptors/lib/browser/index.mjs 9:0-16:30 19:37-48 65:0-78:2 65:0-78:2 65:0-78:2 65:0-78:2 65:0-78:2 65:0-78:2
 @ ../../../node_modules/msw/lib/core/getResponse.mjs 1:0-54 6:15-30
 @ ../../../node_modules/msw/lib/core/index.mjs 14:0-48 22:0-38:2
 @ ./test/fetch.test.ts 30:12-26
 @ ./test/ sync test$ ./fetch.test
 @ ./test/index-webpack.ts 21:21-56

ERROR in ../../../node_modules/is-node-process/lib/index.mjs 6:13-20
Module not found: Error: Can't resolve 'process/browser' in '/home/runner/work/opentelemetry-js/opentelemetry-js/node_modules/is-node-process/lib'
Did you mean 'browser.js'?
BREAKING CHANGE: The request 'process/browser' failed to resolve only because it was resolved as fully specified
(probably because the origin is strict EcmaScript Module, e. g. a module with javascript mimetype, a '*.mjs' file, or a '*.js' file where the package.json contains '"type": "module"').
The extension in the request is mandatory for it to be fully specified.
Add the extension to the request.
 @ ../../../node_modules/msw/lib/core/delay.mjs 1:0-48 7:6-19
 @ ../../../node_modules/msw/lib/core/index.mjs 17:0-28 17:0-28
 @ ./test/fetch.test.ts 30:12-26
 @ ./test/ sync test$ ./fetch.test
 @ ./test/index-webpack.ts 21:21-56

ERROR in ../../../node_modules/msw/lib/browser/index.mjs 90:13-20
Module not found: Error: Can't resolve 'process/browser' in '/home/runner/work/opentelemetry-js/opentelemetry-js/node_modules/msw/lib/browser'
Did you mean 'browser.js'?
BREAKING CHANGE: The request 'process/browser' failed to resolve only because it was resolved as fully specified
(probably because the origin is strict EcmaScript Module, e. g. a module with javascript mimetype, a '*.mjs' file, or a '*.js' file where the package.json contains '"type": "module"').
The extension in the request is mandatory for it to be fully specified.
Add the extension to the request.
 @ ./test/fetch.test.ts 31:18-40
 @ ./test/ sync test$ ./fetch.test
 @ ./test/index-webpack.ts 21:21-56

ERROR in ../../../node_modules/@open-draft/logger/lib/index.mjs
Cannot read properties of undefined (reading 'module')
 @ ../../../node_modules/@mswjs/interceptors/lib/browser/chunk-QED3Q6Z2.mjs 2:0-44 31:22-28
 @ ../../../node_modules/@mswjs/interceptors/lib/browser/index.mjs 9:0-16:30 19:37-48 65:0-78:2 65:0-78:2 65:0-78:2 65:0-78:2 65:0-78:2 65:0-78:2
 @ ../../../node_modules/msw/lib/core/getResponse.mjs 1:0-54 6:15-30
 @ ../../../node_modules/msw/lib/core/index.mjs 14:0-48 22:0-38:2
 @ ./test/fetch.test.ts 30:12-26
 @ ./test/ sync test$ ./fetch.test
 @ ./test/index-webpack.ts 21:21-56

ERROR in ../../../node_modules/is-node-process/lib/index.mjs
Cannot read properties of undefined (reading 'module')
 @ ../../../node_modules/msw/lib/core/delay.mjs 1:0-48 7:6-19
 @ ../../../node_modules/msw/lib/core/index.mjs 17:0-28 17:0-28
 @ ./test/fetch.test.ts 30:12-26
 @ ./test/ sync test$ ./fetch.test
 @ ./test/index-webpack.ts 21:21-56

ERROR in ../../../node_modules/msw/lib/browser/index.mjs
Cannot read properties of undefined (reading 'module')
 @ ./test/fetch.test.ts 31:18-40
 @ ./test/ sync test$ ./fetch.test
 @ ./test/index-webpack.ts 21:21-56

6 errors have detailed information that is not shown.
Use 'stats.errorDetails: true' resp. '--stats-error-details' to show it.

webpack 5.99.8 compiled with 6 errors in 13923 ms
20 05 2025 16:40:44.693:INFO [karma-server]: Karma v6.4.4 server started at http://localhost:9878/
20 05 2025 16:40:44.695:INFO [launcher]: Launching browsers ChromeHeadless with concurrency unlimited
20 05 2025 16:40:44.704:INFO [launcher]: Starting browser ChromeHeadless
20 05 2025 16:40:45.385:INFO [Chrome Headless 136.0.0.0 (Linux x86_64)]: Connected on socket 0oZAYPoUNkCCSa5hAAAB with id 83357362
Chrome Headless 136.0.0.0 (Linux x86_64) ERROR
  Uncaught TypeError: __webpack_modules__[moduleId].call is not a function
  at /tmp/_karma_webpack_263876/runtime.js:31:42
  
  TypeError: __webpack_modules__[moduleId].call is not a function
      at __webpack_require__ (/tmp/_karma_webpack_263876/runtime.js:31:42)
      at eval (webpack-internal:///../../../node_modules/@mswjs/interceptors/lib/browser/chunk-QED3Q6Z2.mjs:10:76)
      at ../../../node_modules/@mswjs/interceptors/lib/browser/chunk-QED3Q6Z2.mjs (/tmp/_karma_webpack_263876/commons.js:568:1)
      at __webpack_require__ (/tmp/_karma_webpack_263876/runtime.js:31:42)
      at eval (webpack-internal:///../../../node_modules/@mswjs/interceptors/lib/browser/index.mjs:18:77)
      at ../../../node_modules/@mswjs/interceptors/lib/browser/index.mjs (/tmp/_karma_webpack_263876/commons.js:590:1)
      at __webpack_require__ (/tmp/_karma_webpack_263876/runtime.js:31:42)
      at eval (webpack-internal:///../../../node_modules/msw/lib/core/utils/matching/matchRequestUrl.mjs:8:77)
      at ../../../node_modules/msw/lib/core/utils/matching/matchRequestUrl.mjs (/tmp/_karma_webpack_263876/commons.js:3731:1)
      at __webpack_require__ (/tmp/_karma_webpack_263876/runtime.js:31:42)

Chrome Headless 136.0.0.0 (Linux x86_64): Executed 0 of 0 ERROR (0.53 secs / 0 secs)

That is a release PR that, as a side-effect of the scripts for handling releases, updating package-lock.json, including this update:

    "node_modules/msw": {
-      "version": "2.7.6",
-      "resolved": "https://registry.npmjs.org/msw/-/msw-2.7.6.tgz",
-      "integrity": "sha512-P+rwn43ktxN8ghcl8q+hSAUlEi0PbJpDhGmDkw4zeUnRj3hBCVynWD+dTu38yLYKCE9ZF1OYcvpy7CTBRcqkZA==",
+      "version": "2.8.4",
+      "resolved": "https://registry.npmjs.org/msw/-/msw-2.8.4.tgz",
+      "integrity": "sha512-GLU8gx0o7RBG/3x/eTnnLd5S5ZInxXRRRMN8GJwaPZ4jpJTxzQfWGvwr90e8L5dkKJnz+gT4gQYCprLy/c4kVw==",

Something in the msw@2.8 update broke the tests. From @pichlermarc

I looked at it briefly and that seems to be due to our use of node assert in the browser tests (which needs an assert polyfill, and that polyfill needs a process polyfill which can't be resolved by webpack when using the new version of msw) - it would likely take some time to find out what's actually causing the issue there.

[pichlermarc]

Turns out that this was a little easier than I initially expected. Opened #5709.