refactor: use nullish coalescing and simplify checks in events

[kamilwronka]

Summary

• Replace || with ?? for nullish coalescing in event-kill.service.ts and event-wrapped.service.ts — prevents incorrect fallback when values are 0 or empty string
• Simplify redundant === null || === undefined checks in event-points.service.ts — Number.isFinite() already returns false for null and undefined

Why each change is safe

• || → ??: Map.get() and optional chaining return undefined (not other falsy values) on miss, so ?? is semantically correct. The key fix is countMapStats() in event-wrapped.service.ts — it can return 0 (valid), which || would incorrectly treat as falsy.
• Simplified Number.isFinite guards: Number.isFinite(null) and Number.isFinite(undefined) both return false, making the explicit null/undefined checks redundant.

Files touched

• apps/api/src/events/services/event-kill.service.ts — 6 || → ?? replacements
• apps/api/src/events/services/event-points.service.ts — 2 simplified conditions
• apps/api/src/events/services/event-wrapped.service.ts — 1 || → ?? replacement

Residual risks

• None. Changes are behavior-preserving for non-zero/non-empty values, and fix a subtle correctness issue for zero values.

Test plan

• All pre-commit hooks passed (lint + format + tests)
• 52 test files, 599 tests passed

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Improved accuracy of event tracking data by correcting how zero values and empty strings are handled in statistics calculations and event metadata serialization.

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[coderabbitai]

📝 Walkthrough

Walkthrough

Three event service files updated to use nullish-coalescing operators (??) instead of logical OR (||) for better handling of optional values, and one file refactored to consolidate null/undefined validation logic using Number.isFinite().

Changes

Cohort / File(s)	Summary
Nullish-coalescing refactoring apps/api/src/events/services/event-kill.service.ts, apps/api/src/events/services/event-wrapped.service.ts	Replace logical OR with nullish-coalescing operators for mapName, unassignedAt serialization, and time-based field defaults to correctly preserve falsy values like 0 and empty strings.
Validation logic consolidation apps/api/src/events/services/event-points.service.ts	Simplify multi-branch null/undefined checks in getTrackingDurationSecondsForRanking() and calculateTrackingDurationPercentage() using single Number.isFinite() guard.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

Nullish coalescing hops through the code,
Where zero and empty now safely show,
The rabbit refactors with finesse and grace,
Replacing old logic with its proper place! 🐰
Valid values preserved, falsy no more.

🚥 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 accurately summarizes the main changes: replacing logical OR with nullish coalescing and simplifying conditional checks across event service files.
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 refactor/nullish-coalescing-events-20260408

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[coderabbitai]

🧹 Nitpick comments (1)

apps/api/src/events/services/event-wrapped.service.ts (1)

701-703: Remove unreachable fallback in mapCount expression.

countMapStats() already guarantees a numeric result, so the fallback chain after it never executes. Simplifying this improves readability.

♻️ Suggested simplification

-      const mapCount =
-        countMapStats(summary.mapStats) ?? heroCoverage?.mapCount ?? 0;
+      const mapCount = countMapStats(summary.mapStats);

🤖 Prompt for AI Agents

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

In `@apps/api/src/events/services/event-wrapped.service.ts` around lines 701 -
703, The assigned mapCount uses an unreachable fallback because
countMapStats(summary.mapStats) always returns a number; replace the
ternary/fallback chain with a direct assignment. Change the mapCount declaration
to call countMapStats(summary.mapStats) only (remove the ??
heroCoverage?.mapCount ?? 0 parts) so the code reads: const mapCount =
countMapStats(summary.mapStats); and remove any now-unnecessary references to
heroCoverage?.mapCount in that expression.

🤖 Prompt for all review comments with AI agents

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

Nitpick comments:
In `@apps/api/src/events/services/event-wrapped.service.ts`:
- Around line 701-703: The assigned mapCount uses an unreachable fallback
because countMapStats(summary.mapStats) always returns a number; replace the
ternary/fallback chain with a direct assignment. Change the mapCount declaration
to call countMapStats(summary.mapStats) only (remove the ??
heroCoverage?.mapCount ?? 0 parts) so the code reads: const mapCount =
countMapStats(summary.mapStats); and remove any now-unnecessary references to
heroCoverage?.mapCount in that expression.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: a6095f9a-41cf-479c-a5d5-70375eddabd5

📥 Commits

Reviewing files that changed from the base of the PR and between f99033e and 94f9277.

📒 Files selected for processing (3)

• apps/api/src/events/services/event-kill.service.ts
• apps/api/src/events/services/event-points.service.ts
• apps/api/src/events/services/event-wrapped.service.ts