Comparação de listas com Conjuntos em Javascript

Compara duas listas em Javascript usando conjuntos.

const areListsEqual = (firstList, secondList) => {
  if (firstList.length !== secondList.length) {
    return false
  }
 
  const firstListAsSet = new Set(firstList)
  const secondListAsSet = new Set(secondList)
 
  if (firstListAsSet.size !== secondListAsSet.size) {
    return false
  }
 
  for (const item of firstListAsSet) {
    if (!secondListAsSet.has(item)) {
      return false
    }
  }
 
  return true
}
 
module.exports = {
  areListsEqual,
}

Testes:

const { areListsEqual } = require('./lists')
 
describe('areListsEqual', () => {
  it('should return true for two equal lists', () => {
    const firstList = [1, 2, 3]
    const secondList = [1, 2, 3]
 
    expect(areListsEqual(firstList, secondList)).toBe(true)
  })
 
  it('should return false for two lists with different lengths', () => {
    const firstList = [1, 2, 3]
    const secondList = [1, 2, 3, 4]
 
    expect(areListsEqual(firstList, secondList)).toBe(false)
  })
 
  it('should return false for two lists with different elements', () => {
    const firstList = [1, 2, 3]
    const secondList = [1, 2, 4]
 
    expect(areListsEqual(firstList, secondList)).toBe(false)
  })
 
  it('should return true for two lists with the same elements in different order', () => {
    const firstList = [1, 2, 3]
    const secondList = [3, 2, 1]
 
    expect(areListsEqual(firstList, secondList)).toBe(true)
  })
 
  it('should return true for two lists with the same elements in different order and repeated elements', () => {
    const firstList = [1, 2, 3, 3]
    const secondList = [3, 2, 1, 3]
 
    expect(areListsEqual(firstList, secondList)).toBe(true)
  })
 
  it('should return false for two lists with the same elements in different order and different number of repeated elements', () => {
    const firstList = [1, 2, 3, 3]
    const secondList = [3, 2, 1, 3, 3]
 
    expect(areListsEqual(firstList, secondList)).toBe(false)
  })
})