🐛 Fixed comment counts for lazy loaded posts

[jonatansberg]

What changed

• Fixed the frontend comment-count loader so it fetches counts for markers inserted after initial page load.
• Added a JSDOM regression test covering lazy-loaded post cards.

Why

Archive pagination inserts post cards after the initial page load. The mutation observer detected those new comment count markers, but it created a debounced fetch function without invoking it, so the counts for lazy loaded posts were never requested.

Testing

• CI=true pnpm --dir ghost/core test:single test/unit/frontend/src/comment-counts.test.js
• Pre-commit hook ran ESLint for the changed JS files.

ref https://linear.app/ghost/issue/ONC-1832/comment-counts-missing-for-post-cards-on-archive-pages

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between b04fa70 and aa585c0.

📒 Files selected for processing (2)

• ghost/core/core/frontend/src/comment-counts/comment-counts.js
• ghost/core/test/unit/frontend/src/comment-counts.test.js

🚧 Files skipped from review as they are similar to previous changes (2)

• ghost/core/core/frontend/src/comment-counts/comment-counts.js
• ghost/core/test/unit/frontend/src/comment-counts.test.js

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Walkthrough

The PR creates a single reusable debouncedFetchCounts wrapper and updates the MutationObserver to call it once per observer callback after collecting all new post IDs. A new unit test suite loads the production script, stubs fetch responses for post ids, appends a post card, and asserts the counts API was requested for the new id and the DOM renders the expected pluralized text.

Suggested reviewers

• kevinansfield
• 9larsons

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title references a bug fix for comment counts on lazy-loaded posts, which directly aligns with the main change: fixing the debounce logic to properly fetch counts for dynamically inserted post cards.
Description check	✅ Passed	The description clearly explains what changed (fixed comment-count loader and added regression test), why it was needed (mutation observer wasn't invoking debounced function), and provides testing details.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

📝 Generate docstrings

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🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch jonatan-onc-1832-comment-counts-missing-for-post-cards-on-archive-pages

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[nx-cloud]

🤖 Nx Cloud AI Fix

Ensure the fix-ci command is configured to always run in your CI pipeline to get automatic fixes in future runs. For more information, please see https://nx.dev/ci/features/self-healing-ci

---

View your CI Pipeline Execution ↗ for commit aa585c0

Command	Status	Duration	Result
nx run ghost:test:ci:integration:no-coverage	✅ Succeeded	1m 59s	View ↗
nx run ghost:test:ci:e2e:no-coverage	✅ Succeeded	10m 17s	View ↗
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nx run ghost:test:ci:e2e	✅ Succeeded	3m 46s	View ↗
nx run ghost:test:ci:legacy	✅ Succeeded	3m 32s	View ↗
nx build @tryghost/signup-form	✅ Succeeded	<1s	View ↗
nx build @tryghost/admin-toolbar	✅ Succeeded	<1s	View ↗
nx build @tryghost/comments-ui	✅ Succeeded	<1s	View ↗
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☁️ Nx Cloud last updated this comment at 2026-06-12 09:48:04 UTC

[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@ghost/core/test/unit/frontend/src/comment-counts.test.js`:
- Around line 23-25: The test uses the Mocha-style hook before(...) which Vitest
doesn't alias; change the hook call from before(...) to beforeAll(...) where
scriptContent is initialized (the before block that reads comment-counts.js) so
the file is loaded in a Vitest-compatible way; update any matching before(...)
reference in comment-counts.test.js that initializes scriptContent to
beforeAll(...) and keep the same callback and fs.readFileSync logic unchanged.

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Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
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Configuration used: Path: .coderabbit.yaml

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📥 Commits

Reviewing files that changed from the base of the PR and between cb39915 and b04fa70.

📒 Files selected for processing (2)

• ghost/core/core/frontend/src/comment-counts/comment-counts.js
• ghost/core/test/unit/frontend/src/comment-counts.test.js