3. Unit Testing. Utils functions format currency and truncate text

gistfile1.txt

// utils/formatters.ts
export const formatCurrency = (amount: number, locale = 'en-US') => {
  return new Intl.NumberFormat(locale, {
    style: 'currency',
    currency: 'USD',
  }).format(amount)
}

export const truncateText = (text: string, maxLength: number) => {
  if (text.length <= maxLength) return text
  return text.slice(0, maxLength) + '...'
}

// utils/__tests__/formatters.test.ts
describe('formatCurrency', () => {
  it('formatea números como moneda USD', () => {
    expect(formatCurrency(1234.56)).toBe('$1,234.56')
  })

  it('maneja números negativos', () => {
    expect(formatCurrency(-50)).toBe('-$50.00')
  })

  it('redondea a 2 decimales', () => {
    expect(formatCurrency(10.999)).toBe('$11.00')
  })
})

describe('truncateText', () => {
  it('no trunca texto menor al límite', () => {
    expect(truncateText('Hello', 10)).toBe('Hello')
  })

  it('trunca texto y añade puntos suspensivos', () => {
    expect(truncateText('Hello World', 5)).toBe('Hello...')
  })

  it('maneja string vacío', () => {
    expect(truncateText('', 5)).toBe('')
  })
})