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import { chain as chainRamda } from 'ramda'
import { chain } from './chain.js'
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 ]  }
  const mdouble = chain(times2)  const 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)).toThrowErrorMatchingInlineSnapshot('"fn(...) is not a function"')})