Escale - Code Challenge

constants.js

const toFrom = {
    0: "zero",
    1: "um",
    2: "dois",
    3: "três",
    4: "quatro",
    5: "cinco",
    6: "seis",
    7: "sete",
    8: "oito",
    9: "nove",
    10: "dez",
    11: "onze",
    12: "doze",
    13: "treze",
    14: "quatorze",
    15: "quinze",
    16: "dezesseis",
    17: "dezessete",
    18: "dezoito",
    19: "dezenove",
    20: "vinte",
    30: "trinta",
    40: "quarenta",
    50: "cinquenta",
    60: "sessenta",
    70: "setenta",
    80: "oitenta",
    90: "noventa",
    100: "cem",
    200: "duzentos",
    300: "trezentos",
    400: "quatrocentos",
    500: "quinhentos",
    600: "seiscentos",
    700: "setecentos",
    800: "oitocentos",
    900: "novecentos"
};

module.exports = toFrom;

index.js

const toFromMap = require('./constants');

function numberToString(number) {
    if(!toFromMap[number]) {
        const string = number.toString(10).split('');
        let head = null;
        let result = null;

        if (number <= 99) {
            head = toFromMap[string[0] + '0'];
            result = `${head} e ${toFromMap[string[1]]}`;
        }

        if (string[0] === '1' && string[2] !== '0') {
            const tail = parseInt(string[1] + string[2]);
            
            result = `cento e ${numberToString(tail)}`;
        }

        return result;
    }

    return toFromMap[number];
}

module.exports = numberToString;

index.test.js

const numberToString = require('./index');

test('Validate 9 decimal', () => {
    expect(numberToString(9)).toBe('nove');
});

test('Validate 21 decimal', () => {
    expect(numberToString(21)).toBe('vinte e um');
});

test('Validate 30 decimal', () => {
    expect(numberToString(30)).toBe('trinta');
});

test('Validate 99 decimal', () => {
    expect(numberToString(99)).toBe('noventa e nove');
});

test('Validate 100 decimal', () => {
    expect(numberToString(100)).toBe('cem');
});

test('Validate 101 decimal', () => {
    expect(numberToString(101)).toBe('cento e um');
});


test('Validate 110 decimal', () => {
    expect(numberToString(110)).toBe('cento e dez');
});

test('Validate 111 decimal', () => {
    expect(numberToString(111)).toBe('cento e onze');
});

test('Validate 121 decimal', () => {
    expect(numberToString(121)).toBe('cento e vinte e um');
});

test('Validate 201 decimal', () => {
    expect(numberToString(201)).toBe('duzentos e um');
});

package.json

{
  "name": "desafio-escale",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "dependencies": {
    "jest": "^24.9.0"
  },
  "devDependencies": {
    "@types/jest": "^24.0.23"
  },
  "scripts": {
    "test": "jest"
  },
  "keywords": [],
  "author": "",
  "license": "ISC"
}