fix(billing): handle missing userStats and prevent crashes

[waleedlatif1]

Summary

• Add defensive validation in getUsage() to prevent toFixed is not a function crashes
• Create ensureUserStatsExists() for on-demand userStats creation when missing
• Call ensureUserStatsExists() in account.create.after hook to handle OAuth account linking
• Call syncUsageLimitsFromSubscription() when users leave orgs to fix NULL limit issue
• Refactor usage visualization: extract constants to consts.ts, add getFilledPillColor()

Type of Change

• Bug fix

Testing

Tested manually

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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1 Skipped Deployment

Project	Deployment	Review	Updated (UTC)
docs	Skipped		Jan 23, 2026 10:30pm

[greptile-apps]

Greptile Summary

This PR adds comprehensive defensive validation to prevent crashes from missing or malformed billing data, specifically addressing toFixed is not a function errors. The changes introduce ensureUserStatsExists() as a safety net for OAuth account linking scenarios where userStats records might not be created, and add Number.isFinite() validation in getUsage() for all numeric fields. Additionally, the PR includes a clean refactoring that extracts usage visualization constants to a dedicated consts.ts file and moves getFilledPillColor() to utils.ts, properly following the project's component pattern guidelines.

Key improvements:

• Added defensive ensureUserStatsExists() call in account.create.after hook to handle OAuth edge cases
• Enhanced getUsage() with Number.isFinite() validation for all numeric fields (current, limit, percentUsed, lastPeriodCost)
• Called ensureUserStatsExists() at the start of getUserUsageData() as additional safety
• Fixed NULL limit issue when users leave organizations by calling syncUsageLimitsFromSubscription()
• Refactored usage visualization: moved constants to consts.ts, relocated getFilledPillColor() to utils.ts, deleted unused helper functions
• Updated all import paths to follow barrel export pattern from @/lib/billing/client

Confidence Score: 5/5

• This PR is safe to merge with defensive fixes that prevent crashes
• All changes are defensive improvements that add safety without breaking existing behavior. The validation logic uses proper fallback values, the refactoring maintains exact functionality while improving code organization, and the ensureUserStatsExists pattern uses onConflictDoNothing to be idempotent
• No files require special attention

Important Files Changed

Filename	Overview
apps/sim/lib/billing/core/usage.ts	Added ensureUserStatsExists() function for defensive userStats creation and integrated it into getUserUsageData()
apps/sim/lib/billing/client/utils.ts	Enhanced getUsage() with comprehensive defensive validation for all numeric fields and added getFilledPillColor() utility
apps/sim/lib/auth/auth.ts	Added ensureUserStatsExists() call in account.create.after hook to handle OAuth account linking edge case
apps/sim/lib/billing/organizations/membership.ts	Added syncUsageLimitsFromSubscription() call when users leave organizations to fix NULL limit issue

[greptile-apps]

Additional Comments (1)

1. apps/sim/app/workspace/[workspaceId]/w/components/sidebar/components/settings-modal/components/usage-header/usage-header.tsx, line 66-71 (link)

   logic: ensure current and limit are numbers before calling toFixed() to prevent crashes. Are current and limit guaranteed to be numbers, or should we add type guards here?

_{10 files reviewed, 2 comments}

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[waleedlatif1]

@greptile