toDictionary.tests.ts

import { toDictionary } from '../src/dictionaries'


describe('Convert array to js object', () => {
    const testData = [
        { key: 'alfa', values: [1, 2, 3], someNumber: 10, someString: 'aaa' },
        { key: 'beta', values: [4], someNumber: 20, someString: 'bbb' },
        { key: 'gamma', values: [5, 6], someNumber: 30, someString: 'ccc' }
    ]


    test('default params', () => {
        const res = testData.reduce(toDictionary(), {})

        expect(res).toEqual({
            alfa: [1, 2, 3],
            beta: [4],
            gamma: [5, 6]
        })
    })


    test('custom keySelector', () => {
        const res = testData.reduce(toDictionary(x => x.someNumber), {})

        expect(res).toEqual({
            10: [1, 2, 3],
            20: [4],
            30: [5, 6]
        })
    })


    test('custom valueSelector', () => {
        const res = testData.reduce(toDictionary(undefined, x => x.someNumber), {})

        expect(res).toEqual({
            alfa: 10,
            beta: 20,
            gamma: 30
        })
    })


    test('custom keySelector and valueSelector', () => {
        const res = testData.reduce(toDictionary(x => x.someString, x => x.key), {})

        expect(res).toEqual({
            aaa: 'alfa',
            bbb: 'beta',
            ccc: 'gamma'
        })
    })


    test('keySelector that returns neither string or number is not allowed', () => {
        expect(() => {
            testData.reduce(toDictionary(x => x.values), {})
        }).toThrow()
    })


    test('complex valueSelector', () => {
        const res = testData.reduce(toDictionary(undefined, x => ({ num: x.someNumber, text: x.someString })), {})

        expect(res).toEqual({
            alfa: { num: 10, text: 'aaa' },
            beta: { num: 20, text: 'bbb' },
            gamma: { num: 30, text: 'ccc' }
        })
    })
})