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import { reverse } from './reverse'
test('happy', () => {  expect(reverse([ 1, 2, 3 ])).toEqual([ 3, 2, 1 ])})
test('with string', () => {  expect(reverse('baz')).toEqual('zab')})
test('it doesn\'t mutate', () => {  const arr = [ 1, 2, 3 ]
  expect(reverse(arr)).toEqual([ 3, 2, 1 ])
  expect(arr).toEqual([ 1, 2, 3 ])})