fix: guard all res.json() calls and non-blocking campaign bootstrap

[bd73-com]

Summary

Hardens every client-side res.json() call with a .catch() guard to prevent unhandled SyntaxError when the server returns non-JSON responses (e.g., reverse proxy 502 HTML pages). Also relocates the welcome campaign bootstrap from server/routes.ts to server/index.ts as a non-blocking fire-and-forget with a 5-second timeout, preventing cold-start delays.

Changes

Client-side JSON resilience

• Add .catch() guard to getQueryFn in client/src/lib/queryClient.ts — covers all hooks using the default query function
• Add .catch() guards to all custom queryFn implementations across hooks: use-monitors.ts, use-tags.ts, use-auth.ts, use-conditions.ts, use-notification-channels.ts, use-notification-preferences.ts, use-slack.ts, use-api-keys.ts, use-campaigns.ts
• Add .catch() guards to page-level fetch calls: AdminErrors.tsx, ExtensionAuth.tsx, Support.tsx, DashboardNav.tsx, UpgradeDialog.tsx
• Expose isError and error from useAuth hook for future error-state UI
• Narrow console.error in ExtensionAuth.tsx to log err.message instead of raw error object

Server-side startup optimization

• Move welcome campaign bootstrap from server/routes.ts to server/index.ts
• Add 5-second Promise.race timeout with structured error handling
• registerRoutes() now returns { httpServer, campaignConfigsReady } to communicate readiness

Test infrastructure

• Switch test environment from happy-dom to jsdom for CI compatibility
• Externalize msw in vitest config to fix module resolution
• Remove happy-dom dependency
• Add/update 14 test files covering the JSON guard pattern (2081 tests, all passing)

How to test

1. npm run check — TypeScript compiles cleanly
2. npm run test — All 84 test files pass (2081 tests)
3. npm run build — Production build succeeds
4. Simulate a non-JSON server response (e.g., HTML 502) and verify the client shows "Unexpected response format from server" instead of a raw SyntaxError

https://claude.ai/code/session_01Ukm6sf45r8mT5fnw8bgYn7

Summary by CodeRabbit

• Chores
  • Improved error logging in extension token handling for better debugging visibility.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: ASSERTIVE

Plan: Pro

Run ID: 248d5b9b-be98-49c0-9f00-8c83c00a094d

📥 Commits

Reviewing files that changed from the base of the PR and between 5fbfe7a and 37f176d.

📒 Files selected for processing (1)

• client/src/pages/ExtensionAuth.tsx

---

📝 Walkthrough

Walkthrough

Modified error logging in the token-fetch catch block to normalize the error output. Changed from logging the raw error object to extracting and logging only the message for Error instances or converting other values to strings, while preserving existing UI error handling behavior.

Changes

Cohort / File(s)	Summary
Error Logging Normalization client/src/pages/ExtensionAuth.tsx	Modified catch block to log normalized error messages using err instanceof Error ? err.message : String(err) instead of raw error objects, preventing unintended exposure of complex objects in console output.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~3 minutes

Possibly related PRs

• fix: guard all res.json() calls against non-JSON responses #332: Directly related modification to the same token-fetch error handling in ExtensionAuth.tsx within the identical catch block.

Suggested labels

fix

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Title check	⚠️ Warning	The PR title describes guarding res.json() calls and campaign bootstrap optimization, but the raw_summary shows only error logging normalization in ExtensionAuth.tsx, with no mention of res.json() guards or bootstrap changes in that file.	The title does not accurately reflect the actual changes in this pull request file. Consider using a more specific title like 'fix: normalize error logging in extension token fetch' to match the actual changeset.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch claude/review-github-issues-5IA9p

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}