time.js

const pify = require('pify');
const Web3 = require('web3');
const web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));
const ethAsync = pify(web3.eth);
const ethGetBlock = ethAsync.getBlock;

web3.currentProvider.sendAsync =  web3.currentProvider.send;

async function advanceBlock () {
  console.log("\tadvancing ");
  await web3.currentProvider.send({
    jsonrpc: '2.0',
    method: 'evm_mine',
    id: new Date().getTime()
  });
  console.log("\tadvanced");
}

// Returns the time of the last mined block in seconds
async function latest () {
  const block = await ethGetBlock('latest');
  return block.timestamp;
}

// Increases ganache time by the passed duration in seconds
// async function increase (duration, web3Replace) {
async function increase (duration) {
  if (duration < 0) throw Error(`Cannot increase time by a negative amount (${duration})`);

  await web3.currentProvider.send({
    jsonrpc: '2.0',
    method: 'evm_increaseTime',
    params: [duration],
    id: Number(Math.random() * 1000).toFixed(0)
  })
  await advanceBlock() // optional (*)
}

/**
 * Beware that due to the need of calling two separate ganache methods and rpc calls overhead
 * it's hard to increase time precisely to a target point so design your test to tolerate
 * small fluctuations from time to time.
 *
 * @param target time in seconds
 */
async function increaseTo (target) {
  const now = (await latest());

  if (target < now) throw Error(`Cannot increase current time (${now}) to a moment in the past (${target})`);
  const diff = target - now;
  return increase(diff);
}

const duration = {
  seconds: function (val) { return val; },
  minutes: function (val) { return val * this.seconds(60); },
  hours: function (val) { return val * this.minutes(60); },
  days: function (val) { return val * this.hours(24); },
  weeks: function (val) { return val * this.days(7); },
  years: function (val) { return val * this.days(365); },
};

module.exports = {
  advanceBlock,
  latest,
  increase,
  increaseTo,
  duration,
};