Summary

• calculator.ts: Throw Error("Division by zero") instead of returning Infinity when dividing by zero
• string-utils.ts: Fix wordCount to handle multiple consecutive spaces; implement truncate with word-boundary logic and "..." suffix
• task-manager.ts: Implement remove, update, and sortBy methods
• date-utils.ts: Use Math.round instead of Math.floor for relative day calculations (36h → "2 days ago")
• validator.ts: Allow TLDs of 2+ characters in email validation; support ports on any hostname in URL validation

Test Results

All 60 tests pass across 5 test files with 70 expect() calls.

Assumptions

• truncate uses word-boundary truncation where the "..." suffix counts toward maxLength
• sortBy("priority") orders high > medium > low
• sortBy("createdAt") orders oldest first
• formatRelative uses Math.round for day rounding (consistent with test expectations)