fix: assign display names to same-language code tabs

[shivxmsharma]

Description

When two or more consecutive code blocks share the same language (e.g. two js blocks back to back), @node-core/rehype-shiki groups them into a CodeTabs component. The problem is both tabs end up labelled identically — "JS | JS" — which doesn't help the reader distinguish between them.

This PR adds a small rehype plugin (src/utils/code-tabs.mjs) that runs before @node-core/rehype-shiki in the getRemarkRecma pipeline. It scans consecutive code blocks either language appears more than once in a group, it injects displayName metadata onto each duplicate so the tabs render as "(1)", "(2)" instead. Blocks with different languages are left untouched.

Validation

• All 363 existing + new tests pass (npm test).
• Lint and formatting are clean (npm run lint, npm run format:check).
• Manually verified with a test markdown containing two consecutive js blocks — confirmed displayName="(1)" and displayName="(2)" are injected into data.meta.

Related Issues

Addresses #596

Check List

• I have read the Contributing Guidelines and made commit messages that follow the guideline.
• I have run node --run test and all tests passed.
• I have check code formatting with node --run format & node --run lint.
• I've covered new added functionality with unit tests if necessary.

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Project	Deployment	Actions	Updated (UTC)
api-docs-tooling	Ready	Preview	Mar 30, 2026 3:15pm

[codecov]

Codecov Report

❌ Patch coverage is 95.67568% with 8 lines in your changes missing coverage. Please review.
✅ Project coverage is 76.63%. Comparing base (7e3f5d2) to head (bb0429e).
⚠️ Report is 4 commits behind head on main.

Files with missing lines	Patch %	Lines
src/utils/code-tabs.mjs	93.39%	7 Missing ⚠️
src/utils/remark.mjs	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #730      +/-   ##
==========================================
+ Coverage   76.15%   76.63%   +0.47%     
==========================================
  Files         151      157       +6     
  Lines       13641    13951     +310     
  Branches     1066     1125      +59     
==========================================
+ Hits        10388    10691     +303     
- Misses       3248     3255       +7     
  Partials        5        5              

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[avivkeller]

I think this bug was already solved

[avivkeller]

Indeed it is: https://openjs-foundation.slack.com/archives/C09EXEEHFKP/p1774740421197399

Please double-check this sort of thing.

[shivxmsharma]

Indeed it is: https://openjs-foundation.slack.com/archives/C09EXEEHFKP/p1774740421197399

Please double-check this sort of thing.

I am unable to login to this.

[avivkeller]

I am unable to login to this.

To access our Slack, see https://slack-invite.openjsf.org/

To "double-check this sort of thing", you can test local deployments before spending time on a change. It'll save lots of time :)

[shivxmsharma]

I am unable to login to this.

To access our Slack, see https://slack-invite.openjsf.org/

To "double-check this sort of thing", you can test local deployments before spending time on a change. It'll save lots of time :)

Thank you for your feedback, it'll really help. I'll take more care next time before raising a PR:)