After these changes are in a good place, we'll have to update the CI to make these required.

Still trying to work out why the build cache it not being found from the windows tests:
https://github.com/getsentry/sentry-javascript/runs/5318935426?check_suite_focus=true#step:5:24

diff --git a/packages/utils/test/is.test.ts b/packages/utils/test/is.test.ts
index 0b8f1a9d..5b06b7ad 100644
--- a/packages/utils/test/is.test.ts
+++ b/packages/utils/test/is.test.ts
@@ -1,6 +1,6 @@
-import { resolvedSyncPromise } from '../dist';
 import { isDOMError, isDOMException, isError, isErrorEvent, isInstanceOf, isPrimitive, isThenable } from '../src/is';
 import { supportsDOMError, supportsDOMException, supportsErrorEvent } from '../src/supports';
+import { resolvedSyncPromise } from '../src/syncpromise';
 
 class SentryError extends Error {
   public name: string;
diff --git a/packages/utils/test/syncpromise.test.ts b/packages/utils/test/syncpromise.test.ts
index 7c693c82..6164c666 100644
--- a/packages/utils/test/syncpromise.test.ts
+++ b/packages/utils/test/syncpromise.test.ts
@@ -1,5 +1,4 @@
-import { rejectedSyncPromise, resolvedSyncPromise } from '../dist';
-import { SyncPromise } from '../src/syncpromise';
+import { rejectedSyncPromise, resolvedSyncPromise, SyncPromise } from '../src/syncpromise';
 
 describe('SyncPromise', () => {
   test('simple', () => {

Needs to be applied, importing from the dist files is a code smell - I'll open the PR

As for the build.test.ts 🤔

Could we debug by running GHA locally with https://github.com/nektos/act?

Needs to be applied, importing from the dist files is a code smell - I'll open the PR

Made this change in #4631

build.test.ts

I'd be fine with moving https://github.com/getsentry/sentry-javascript/blob/master/packages/utils/test/build.test.ts into a node script that runs in the job_browser_build_tests

We shouldn't be asserting on built files in jest unit tests.

Thanks, will take another look!

Opened #4658 for the build unit tests

I managed to work around the fact that build caches cannot be shared between platforms by instead uploading and downloading artefacts.

However, sharing an install cache between Windows agents does not work because the yarn workspace symlinks do not get copied. I think this is because unlike unix platforms, symlinks on Windows are not stored in the regular file system 🤦‍♂️.

This means that on Windows we have to do a full yarn install in every agent and this is very very slow.

I'm not convinced it's a great idea to add this into the CI build yet!

This pull request has gone three weeks without activity. In another week, I will close it.

But! If you comment or otherwise update it, I will reset the clock, and if you label it Status: Backlog or Status: In Progress, I will leave it alone ... forever!

"A weed is but an unloved flower." ― Ella Wheeler Wilcox 🥀