fix(frontend): promote token count display at unit boundaries

[thedavidweng]

Problem

formatTokenCount in packages/frontend/src/lib/utils.ts displays token counts in compact form (K/M/B/T) using toFixed(1) after dividing by the unit. When a value is near a unit boundary, toFixed(1) rounds up to "1000.0", producing displays like:

• 999,950 → "1000.0K" (should be "1.0M")
• 999,999,500 → "1000.0M" (should be "1.0B")

This is the root cause of #474 — tokens on the profile page appearing "rounded up" with the wrong unit.

Fix

Before formatting, check if the divided value is ≥ 999.95 (the threshold where toFixed(1) rounds to "1000.0"). When it is, promote to the next unit:

if (count >= 1_000_000) {
  const val = count / 1_000_000;
  return val >= 999.95
    ? `${(val / 1000).toFixed(1)}B`   // promote: 999.95M → 1.0B
    : `${val.toFixed(1)}M`;
}

Same pattern for K→M and B→T boundaries.

Verification

New test file __tests__/lib/formatTokenCount.test.ts covers:

• Normal formatting at each unit (K/M/B/T)
• Boundary promotion: 999,950 → "1.0M", 999,999,500 → "1.0B", 999,999,999,500 → "1.0T"
• Values below the boundary remain unchanged

Closes #474

---

Summary by cubic

Fixes token count rounding near unit boundaries in formatTokenCount so we don’t display "1000.0K/M/B". Values that would round up are promoted to the next unit (e.g., 999,950 → 1.0M); fixes #474.

• Bug Fixes
  • Promote when divided value ≥ 999.95 for K→M, M→B, and B→T; otherwise keep 1-decimal format.
  • Added packages/frontend/__tests__/lib/formatTokenCount.test.ts covering normal and boundary cases.

^{Written for commit d3d655b. Summary will update on new commits.}

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Project	Deployment	Actions	Updated (UTC)
tokscale	Ready	Preview, Comment	Jun 8, 2026 10:49am

[cubic-dev-ai]

No issues found across 2 files

_{Re-trigger cubic}

[thedavidweng]

Frontend CI failing due to PR #685

[junhoyeo]

Thanks!