feat: DR-7614 Add posthog to blog

[carlagn]

Summary by CodeRabbit

• New Features
  • Integrated analytics tracking on the blog to monitor user engagement and usage patterns for improving user experience.

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Project	Deployment	Actions	Updated (UTC)
blog	Ready	Preview, Comment	Mar 12, 2026 3:28pm
docs	Ready	Preview, Comment	Mar 12, 2026 3:28pm
eclipse	Ready	Preview, Comment	Mar 12, 2026 3:28pm

[coderabbitai]

Walkthrough

This pull request adds PostHog analytics integration to the blog application by introducing a new client-side instrumentation module and its corresponding dependency, while also updating the root package manager specification with a SHA512 integrity hash for package consistency.

Changes

Cohort / File(s)	Summary
PostHog Analytics Integration apps/blog/package.json, apps/blog/src/instrumentation-client.ts	Adds posthog-js dependency via catalog reference and introduces new TypeScript client module that initializes PostHog analytics with environment configuration (api_host, pageview capture, site metadata).
Package Manager Specification package.json	Updates packageManager field to include SHA512 integrity hash for pnpm@10.30.0, strengthening version verification and reproducibility without altering runtime behavior.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

🚥 Pre-merge checks | ✅ 3

✅ Passed checks (3 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'feat: DR-7614 Add posthog to blog' accurately describes the main change: adding PostHog analytics instrumentation to the blog application.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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Build	Status	Details	Updated (UTC)
default (Inspect)	⚠️ Changes detected (Review)	1 removed	Mar 12, 2026, 3:35 PM

[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (1)

apps/blog/src/instrumentation-client.ts (1)

3-4: Non-null assertion on environment variable may cause silent failures.

Using process.env.NEXT_PUBLIC_POSTHOG_KEY! assumes the key is always defined. If it's missing (e.g., in a local dev environment without the env var set), PostHog will receive undefined as the API key, potentially causing initialization errors or silent failures.

A defensive approach ensures graceful degradation:

🛡️ Proposed defensive initialization

+const posthogKey = process.env.NEXT_PUBLIC_POSTHOG_KEY;
+
+if (posthogKey) {
-posthog.init(process.env.NEXT_PUBLIC_POSTHOG_KEY!, {
+  posthog.init(posthogKey, {
   api_host: process.env.NEXT_PUBLIC_POSTHOG_HOST,
   capture_pageview: "history_change",
-  defaults: "2025-11-30",
   loaded: (posthog) => {
     posthog.register({
       site_name: "mono-blog",
-      environment: "production",
+      environment: process.env.NODE_ENV,
     });
   },
 });
+}

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@apps/blog/src/instrumentation-client.ts` around lines 3 - 4, Replace the
non-null assertion on process.env.NEXT_PUBLIC_POSTHOG_KEY in the posthog.init
call with a defensive check: verify NEXT_PUBLIC_POSTHOG_KEY is defined before
calling posthog.init (in the instrumentation client where posthog.init is
invoked), and if it's missing, skip initialization or call posthog.init with a
safe fallback only after logging/warning (use
process.env.NEXT_PUBLIC_POSTHOG_HOST as needed), ensuring you surface an
explicit log message or telemetry so missing key cases are visible instead of
passing undefined into posthog.init.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@apps/blog/src/instrumentation-client.ts`:
- Line 10: The hardcoded environment: "production" should be replaced with a
derived value so dev/staging traffic isn't mislabeled; update the
object/property named environment (in apps/blog/src/instrumentation-client.ts)
to read from an environment variable such as process.env.NEXT_PUBLIC_ENVIRONMENT
with a fallback to process.env.NODE_ENV and then to "production" only as last
resort, and ensure any build-time exposure requirements are respected (use
NEXT_PUBLIC_ prefix if this value must be client-accessible).

---

Nitpick comments:
In `@apps/blog/src/instrumentation-client.ts`:
- Around line 3-4: Replace the non-null assertion on
process.env.NEXT_PUBLIC_POSTHOG_KEY in the posthog.init call with a defensive
check: verify NEXT_PUBLIC_POSTHOG_KEY is defined before calling posthog.init (in
the instrumentation client where posthog.init is invoked), and if it's missing,
skip initialization or call posthog.init with a safe fallback only after
logging/warning (use process.env.NEXT_PUBLIC_POSTHOG_HOST as needed), ensuring
you surface an explicit log message or telemetry so missing key cases are
visible instead of passing undefined into posthog.init.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 659ff7db-fe2b-4b9a-a264-9b7132fa37e3

📥 Commits

Reviewing files that changed from the base of the PR and between 0f1bc35 and 64b81fe.

⛔ Files ignored due to path filters (2)

• apps/blog/public/fonts/MonaSansMonoVF[wght].woff2 is excluded by !**/*.woff2
• pnpm-lock.yaml is excluded by !**/pnpm-lock.yaml

📒 Files selected for processing (3)

• apps/blog/package.json
• apps/blog/src/instrumentation-client.ts
• package.json