worker: emit worker exit notifications on BroadcastChannel

[SudhansuBandha]

Expose worker termination notifications through BroadcastChannel so consumers can observe when a worker exits and inspect its thread ID and exit code.

Fixes: #59053

[codecov]

Codecov Report

❌ Patch coverage is 97.26027% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 90.40%. Comparing base (bbd566d) to head (c0f9084).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/node_messaging.cc	96.72%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #65575      +/-   ##
==========================================
- Coverage   92.74%   90.40%   -2.35%     
==========================================
  Files         422      791     +369     
  Lines      193170   276057   +82887     
  Branches    29783    52983   +23200     
==========================================
+ Hits       179160   249575   +70415     
- Misses      13682    16902    +3220     
- Partials      328     9580    +9252     

Files with missing lines	Coverage Δ
lib/internal/worker/io.js	99.24% <100.00%> (+<0.01%)	⬆️
src/node_messaging.h	72.00% <100.00%> (ø)
src/node_messaging.cc	83.81% <96.72%> (ø)

... and 498 files with indirect coverage changes

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[SudhansuBandha]

node/src/node_messaging.cc

Line 823 in 144e679

HandleScope handle_scope(env()->isolate());

node/src/node_messaging.cc

Line 853 in 144e679

HandleScope handle_scope(env()->isolate());

I have observed the same line being present twice in OnMessage handler I have kept the first and removed the second. If this is not to be done then please let me know @addaleax I will revert it.

[SudhansuBandha]

@MikeMcC399
I ran the full Windows test suite against my PR. The suite completed with 7346 passing and 46 failures. Most of the failures are Windows environment-specific: symlink tests fail with EPERM, and some tests invoking Unix utilities failed because cat/head were unavailable in my development Windows environment.

I have not received any failure on my Windows machine because of my changes in PR. Can you provide me a suitable approach where I can recreate the CI failure on Windows machine. Will WSL/MSYS2 help in this regards?

[SudhansuBandha]

Thank you @MikeMcC399 for your help. I believe I have missed a failing test in my changes which I am currently looking at it. Hopefully CI issues will get resolved after this.

[SudhansuBandha]

@MikeMcC399 I have fixed the failing test but still the CI issue is not getting resolved. If it is possible, can you or anyone else debug these failing CI issues against the test suite on Linux/MacOs. I am not able to reproduce on Windows and due to limited hardware resources it is difficult for me to have a dual setup of Windows and Linux on my machine

[MikeMcC399]

I'm sorry, I won't be able to help you further with the test problems.

[SudhansuBandha]

@MikeMcC399 CI looks to be good for now. Hope that we can take this further!!!😄

[MikeMcC399]

CI looks to be good for now. Hope that we can take this further!!!😄

Perhaps @addaleax will be able to review again now that your tests are succeeding?