doc: fix URL postMessage example in worker_threads

[kovan]

Fix the postMessage(new URL(...)) example in doc/api/worker_threads.md which claims to print {} but actually throws DataCloneError since v21.0.0 (d920b7c).

Verified against src/node_messaging.cc — URL objects are not serializable and throw DataCloneError: Cannot clone object of unsupported type.

Fixes: #60504

[nodejs-github-bot]

Commit Queue failed

- Loading data for nodejs/node/pull/62203
✔  Done loading data for nodejs/node/pull/62203
----------------------------------- PR info ------------------------------------
Title      doc: fix URL postMessage example in worker_threads (#62203)
   ⚠  Could not retrieve the email or name of the PR author's from user's GitHub profile!
Branch     kovan:doc-worker-url-postmessage -> nodejs:main
Labels     doc, author ready, worker
Commits    1
 - doc: fix URL postMessage example in worker_threads
Committers 1
 - kovan <xaum.io@gmail.com>
PR-URL: https://github.com/nodejs/node/pull/62203
Fixes: https://github.com/nodejs/node/issues/60504
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
------------------------------ Generated metadata ------------------------------
PR-URL: https://github.com/nodejs/node/pull/62203
Fixes: https://github.com/nodejs/node/issues/60504
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
--------------------------------------------------------------------------------
   ℹ  This PR was created on Wed, 11 Mar 2026 10:21:10 GMT
   ✔  Approvals: 1
   ✔  - Luigi Pinca (@lpinca): https://github.com/nodejs/node/pull/62203#pullrequestreview-3949229592
   ✔  Last GitHub CI successful
   ℹ  Green GitHub CI is sufficient
--------------------------------------------------------------------------------
   ✔  No git cherry-pick in progress
   ✔  No git am in progress
   ✔  No git rebase in progress
--------------------------------------------------------------------------------
- Bringing origin/main up to date...
From https://github.com/nodejs/node
 * branch                  main       -> FETCH_HEAD
✔  origin/main is now up-to-date
- Downloading patch for 62203
From https://github.com/nodejs/node
 * branch                  refs/pull/62203/merge -> FETCH_HEAD
✔  Fetched commits as 5605f6bca4be..4c63b211a5e6
--------------------------------------------------------------------------------
Auto-merging doc/api/worker_threads.md
[main fda8b92a33] doc: fix URL postMessage example in worker_threads
 Author: kovan <xaum.io@gmail.com>
 Date: Wed Mar 11 01:40:09 2026 +0100
 1 file changed, 3 insertions(+), 6 deletions(-)
   ✔  Patches applied
--------------------------------------------------------------------------------
--------------------------------- New Message ----------------------------------
doc: fix URL postMessage example in worker_threads
The example claimed that posting a URL object via MessageChannel would

print an empty object, but since v21.0.0 (commit d920b7c94b8) it

throws a DataCloneError. Update the example and surrounding text to

reflect the current behavior.
Fixes: #60504
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

PR-URL: #62203

Fixes: #60504

Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
[main 7ee82b463a] doc: fix URL postMessage example in worker_threads

Author: kovan <xaum.io@gmail.com>

Date: Wed Mar 11 01:40:09 2026 +0100

1 file changed, 3 insertions(+), 6 deletions(-)

✖  7ee82b463a72434d1b0a6d876d69aab38f4da790

✔  0:0      no Assisted-by metadata                   assisted-by-is-trailer

✔  0:0      Co-authored-by is a trailer               co-authored-by-is-trailer

✔  6:7      Valid fixes URL.                          fixes-url

✔  0:0      blank line after title                    line-after-title

✔  0:0      line-lengths are valid                    line-length

✔  0:0      metadata is at end of message             metadata-end

✔  9:8      PR-URL is valid.                          pr-url

✔  0:0      reviewers are valid                       reviewers

✖  0:0      Commit must have a "Signed-off-by" trailer signed-off-by

✔  0:0      valid subsystems                          subsystem

✔  0:0      Title is formatted correctly.             title-format

✔  0:0      Title is <= 50 columns.                   title-length
ℹ  Please fix the commit message and try again.

Please manually ammend the commit message, by running

git commit --amend

Once commit message is fixed, finish the landing command running

git node land --continue

https://github.com/nodejs/node/actions/runs/26131088912

[kovan]

Added the missing Signed-off-by trailer and force-pushed the PR branch.

New head: dc38a01