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import {chain} from './chain'import {chain as chainRamda} from 'ramda'
const duplicate = n => [n, n]
test('happy', () => {  const fn = x => [x * 2]  const list = [1, 2, 3]
  const result = chain(fn, list)
  expect(result).toEqual([2, 4, 6])})
test('maps then flattens one level', () => {  expect(chain(duplicate, [1, 2, 3])).toEqual([1, 1, 2, 2, 3, 3])})
test('maps then flattens one level - curry', () => {  expect(chain(duplicate)([1, 2, 3])).toEqual([1, 1, 2, 2, 3, 3])})
test('flattens only one level', () => {  const nest = n => [[n]]  expect(chain(nest, [1, 2, 3])).toEqual([[1], [2], [3]])})
test('can compose', () => {  function dec(x) {    return [x - 1]  }  function times2(x) {    return [x * 2]  }
  var mdouble = chain(times2)  var mdec = chain(dec)  expect(mdec(mdouble([10, 20, 30]))).toEqual([19, 39, 59])})
test('@types/ramda broken test', () => {  const score = {    maths: 90,    physics: 80,  }
  const calculateTotal = score => {    const {maths, physics} = score    return maths + physics  }
  const assocTotalToScore = (total, score) => ({...score, total})
  const calculateAndAssocTotalToScore = chainRamda(    assocTotalToScore,    calculateTotal  )  expect(() => calculateAndAssocTotalToScore(score)).toThrow()})