All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

• Initial release
• rounded() default export with halfUp and bankers rounding methods
• rounded.cash() for physical denomination rounding (nearest 0.05 / 0.10 / 0.25 etc.)
• rounded.currency() for ISO 4217 currency-aware rounding
• Named exports: halfUp, bankers, cash, currency, CURRENCY_PRECISION
• RoundingMethod, RoundedOptions, CurrencyRoundingMethod, CurrencyOptions, CashOptions, and CurrencyCode TypeScript types
• src/utils/guard.ts — null-safety for all public inputs
• src/utils/precision.ts — string-based decimal shift to prevent float drift
• Full TypeScript support with type definitions in dist/types
• Zero dependencies
• Dual package support (CommonJS + ESM) via tsconfig.esm.json and tsconfig.cjs.json
• Post-build script scripts/fix-cjs.mjs to rename .js → .cjs and patch internal require() paths
• Test suite with Vitest covering halfUp, bankers, cash, currency, and the main rounded() wrapper

• halfUp: Standard receipt/POS rounding — ties always round toward +∞
• bankers: Round half to even — reduces cumulative bias in high-volume transaction sets
• cash: Rounds to nearest physical denomination — configurable via nearest option (default 0.05)
• precision: Configurable decimal places on rounded(), default 2
• method: Selectable rounding algorithm on rounded() and rounded.currency()

• Input validation via guard() — NaN, null, undefined, Infinity, and -Infinity all return null, never throw
• Float drift prevention via toPrecision(15) string-based decimal shifting before any arithmetic — guards against cases like 1.005 * 100 = 100.4999...