code-refactor.md

Code Refactor Review

User Prompt

Use do-think-twice to review this working function. Should I refactor it?

export function formatPrice(cents: number, currency = "USD") {
  if (!Number.isInteger(cents)) {
    throw new Error("cents must be an integer");
  }

  const dollars = cents / 100;
  return new Intl.NumberFormat("en-US", {
    style: "currency",
    currency,
  }).format(dollars);
}

Without Do Think Twice

Create a MoneyFormatter class, move validation into a separate helper, add a currency enum, and make the locale configurable for future flexibility.

With Do Think Twice

• Overall judgment: Keep the function as-is unless the product already needs multiple locales or shared money-formatting behavior.
• Must fix: None visible from this snippet.
• Strongly recommended: Add tests for negative values, zero, non-integer input, and non-USD currency if they are not already covered.
• Optional: Add a locale parameter only if callers already need non-US formatting. Otherwise the default is simpler.
• Not recommended: Do not introduce a class, enum, or abstraction only for "cleanliness." That adds API surface without solving a current problem.

Why This Is Better

The guided response preserves simple working code and redirects effort toward tests and actual requirements instead of speculative architecture.