Fix negative streak handling in getFreebuffStreakGlmWeeklyUnits

[pavankumar-vh]

Overview

Fix negative streak handling in the getFreebuffStreakGlmWeeklyUnits function in common/src/util/freebuff-streak.ts.

Bug Description

The function didn't validate that streak is non-negative. If streak was negative, Math.floor(streak / INTERVAL) would be negative, and Math.min with the positive max would return the negative value, resulting in a negative GLM bonus.

Fix

Added Math.max(0, streak) to ensure streak is non-negative before processing.

Testing

Added a new test case that verifies:

• Negative streak values (-1, -100) return 0
• Zero streak returns 0
• Positive streaks work as expected (7 → 1, 14 → 2)

All 15 tests pass (including the new one).

Files Changed

• common/src/util/freebuff-streak.ts - Added negative streak validation
• common/src/util/__tests__/freebuff-streak.test.ts - Added test coverage

Scope

This change only touches common/ which is an approved contribution area per the Contributing Guide.

[codebuff-team]

Good, focused fix. common/ is in scope and the change is minimal and low-risk.

The core question is whether streak can actually be negative at the call site — if callers always pass a validated non-negative streak, this is purely defensive. But defending internal utility functions against malformed input is reasonable, especially if streak could ever come from unsanitized user/session state or a miscalculated date diff (e.g. clock skew, timezone bugs) upstream. Worth checking whether calculateFreebuffStreak (or wherever the streak value that feeds this function originates) can ever produce a negative number — if so, this is a real bug fix; if not, it's cheap insurance either way.

The test added is clear and directly verifies the fix (-1, -100, 0, 7, 14). Nice touch keeping the existing test style consistent with the file.

One minor nit: consider using Math.max(0, Math.floor(safeStreak / ...)) reasoning is already handled correctly since Math.floor of a non-negative number stays non-negative — no issue there, just a note that the fix is correctly ordered (clamp before floor).

Small, well-scoped, has a test, easy to port. Recommend acceptance, though maintainers should double check whether negative streak is actually reachable in production to confirm this is fixing a real bug and not just a hypothetical.