turash/bugulma/frontend/lib/fin/index.test.ts

import { describe, expect, it } from 'vitest';
import { formatCurrency, formatNumber, Money } from '.';

describe('fin utilities', () => {
  it('formats numbers with formatNumber', () => {
    expect(formatNumber(1234567)).toBe(new Intl.NumberFormat('en-US').format(1234567));
  });

  it('formats currency with defaults', () => {
    const formatted = formatCurrency(1234);
    expect(formatted).toBe(
      new Intl.NumberFormat('en-US', {
        style: 'currency',
        currency: 'EUR',
        minimumFractionDigits: 0,
        maximumFractionDigits: 0,
      }).format(1234)
    );
  });

  it('money arithmetic preserves cents', () => {
    const a = new Money(10.25); // 10.25 EUR
    const b = new Money(2.5); // 2.50 EUR
    const sum = a.add(b);
    expect(sum.toNumber()).toBeCloseTo(12.75, 5);

    const mul = a.mul(3);
    expect(mul.toNumber()).toBeCloseTo(30.75, 5);
  });

  it('money.format delegates to formatCurrency', () => {
    const a = new Money(123.45);
    const formatted = a.format({ currency: 'EUR', locale: 'en-US' });
    expect(formatted).toBe(
      new Intl.NumberFormat('en-US', {
        style: 'currency',
        currency: 'EUR',
        minimumFractionDigits: 2,
        maximumFractionDigits: 2,
      }).format(123.45)
    );
  });
});