all.spec.js

const map = require('./map')
const filter = require('./filter')
const find = require('./find')
const some = require('./some')
const sum = require('./sum')
const prod = require('./prod')
const min = require('./min')
const max = require('./max')
const and = require('./and')
const or = require('./or')
const concatList = require('./concatList')
const concatObject = require('./concatObject')
const concatString = require('./concatString')
const compose = require('./compose')

describe('use reduce rewrite ', () => {
    const LIST = [1, 2, 3, 4]
    const LIST_CHARS = ['A', 'B', 'C', 'D']
    const LIST_BOOLS = [true, false, true, false]
    const IS_EVEN = a => a % 2 === 0
    const IS_ODD = a => a % 2 !== 0

    it('map', () => {
        expect(map(LIST, IS_ODD)).toEqual(LIST.map(IS_ODD))
        expect(map(LIST, IS_EVEN)).toEqual(LIST.map(IS_EVEN))
    })

    it('filter', () => {
        expect(filter(LIST, IS_EVEN)).toEqual(LIST.filter(IS_EVEN))
        expect(filter(LIST, IS_ODD)).toEqual(LIST.filter(IS_ODD))
    })

    it('find', () => {
        expect(find(LIST, IS_EVEN)).toEqual(LIST.find(IS_EVEN))
    })

    it('some', () => {
        expect(some(LIST, IS_EVEN)).toEqual(LIST.some(IS_EVEN))
    })
    describe('monoids', () => {
        it('sum', () => {
            expect(sum(LIST)).toEqual(10)
        })
        it('prod', () => {
            expect(prod(LIST)).toEqual(24)
        })
        it('min', () => {
            expect(min(LIST)).toEqual(1)
        })
        it('max', () => {
            expect(max(LIST)).toEqual(4)
        })
        it('and', () => {
            expect(and(LIST_BOOLS)).toEqual(false)
        })
        it('or', () => {
            expect(or(LIST_BOOLS)).toEqual(true)
        })
        it('concatList', () => {
            expect(concatList([LIST, LIST])).toEqual([1, 2, 3, 4, 1, 2, 3, 4])
        })
        it('concatObject', () => {
            expect(
                concatObject([{ foo: 'FOO' }, { bar: 'BAR' }, { baz: 'BAZ' }])
            ).toEqual({ foo: 'FOO', bar: 'BAR', baz: 'BAZ' })
        })
        it('concatString', () => {
            expect(concatString(LIST_CHARS)).toEqual('ABCD')
        })
        it('compose', () => {
            expect(
                compose([a => 2 * a, a => a + 4, a => a.toString()])(4)
            ).toEqual('12')
        })
    })
})