Working with JavaScript async functions

async-functions.js

const promises = require('./promises');

/** Retrieve data */

async function getInfo() {
  const country = await promises.getCountry();
  const time = await promises.getTime();
  const weather = await promises.getWeather();

  return { country, time, weather };
}

getInfo()
  .then((result) => {
    console.log(`Returned from the async function: ${JSON.stringify(result)}`);
  });

/** Error handling */

async function simulateError() {
  const whatever = await promises.throwError();

  return { whatever };
}

async function simulateTry() {
  try {
    await promises.throwError();
  } catch (err) {
    throw new Error('I was thrown from the catch statement');
  }

  return { whatever };
}

simulateError()
  .then(/* nothing happens */)
  .catch((err) => {
    console.log(`Catched from the async function: ${err}`);
  });

simulateTry()
  .then(/* nothing happens */)
  .catch((err) => {
    console.log(`Catched from the async function: ${err}`);
  });

promises.js

const http = require('http');

const getWeather = () => {
  return new Promise((resolve, reject) => {
    http.get({
      host: 'www.mocky.io',
      path: `/v2/590215d50f0000a018d2cb0b`,
    }, (response) => {
      let body = '';
      response.on('data', data => body += data);
      response.on('end', () => resolve(JSON.parse(body)));
    });
  });
}

const getTime = () => {
  return new Promise((resolve, reject) => {
    http.get({
      host: 'www.mocky.io',
      path: `/v2/590216980f0000b418d2cb0e`,
    }, (response) => {
      let body = '';
      response.on('data', data => body += data);
      response.on('end', () => resolve(JSON.parse(body)));
    });
  });
}

const getCountry = () => {
  return new Promise((resolve, reject) => {
    http
      .get({
        host: 'www.mocky.io',
        path: `/v2/590216aa0f0000b318d2cb0f`,
      }, (response) => {
        let body = '';
        response.on('data', data => body += data);
        response.on('end', () => resolve(JSON.parse(body)));
      });
  });
}

const throwError = () => {
  return new Promise((resolve, reject) => {
    setTimeout(() => {
      reject(new Error('Example'));
    }, 500);
  });
};

module.exports = {
  getCountry,
  getTime,
  getWeather,
  throwError
};