transfer-stats/lib/__tests__/index.test.js

Track download/upload and provide transfer stats

'use strict';

/* eslint-env jest */

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

expect.extend({
  toBeWithin20PercentOf(received, argument) {
    const pass = received * 1.2 > argument && received / 1.2 < argument;
    if (pass) {
      return {
        message: () => `expected ${received} not to be within 20% of ${argument}`,
        pass: true
      };
    }
    return {
      message: () => `expected ${received} to be within 20% of ${argument}`,
      pass: false
    };
  }
});

let transfer;
let elapsedTime;
elapsedTime = 0;

const delay = () => {
  elapsedTime += 300;
  return new Promise(resolve => setTimeout(resolve, 300));
};

describe('simple transfer flow', () => {
  it('should create new file transfer', () => {
    transfer = new Transfer({
      bytesTotal: 10000
    });
    expect(transfer.started).toBe(false);
    expect(transfer.finished).toBe(false);
    expect(transfer.bytesCompleted).toBe(0);
    expect(transfer.bytesTotal).toBe(10000);
    expect(transfer.bytesRemaining).toBe(10000);
    expect(transfer.percentage).toBe(0);
  });

  it('should error when transferring bytes on unstarted transfer', () => {
    expect(() => {
      transfer.updateBytes(50);
    }).toThrow();
  });

  it('should start transfer', () => {
    transfer.start();
    expect(transfer.started).toBe(true);
    expect(transfer.finished).toBe(false);
    expect(transfer.bytesCompleted).toBe(0);
    expect(transfer.bytesRemaining).toBe(10000);
    expect(transfer.bytesTotal).toBe(10000);
    expect(transfer.percentage).toBe(0);
    return delay();
  });

  it('should transfer data', () => {
    transfer.updateBytes(100);
    expect(transfer.started).toBe(true);
    expect(transfer.finished).toBe(false);
    expect(transfer.bytesCompleted).toBe(100);
    expect(transfer.bytesRemaining).toBe(9900);
    expect(transfer.bytesTotal).toBe(10000);
    expect(transfer.percentage).toBe(0.01);
    expect(transfer.msElapsed).toBeWithin20PercentOf(elapsedTime);
    const bps = 333; // 100B / 300MS * 1000;
    expect(transfer.bytesPerSecond).toBeWithin20PercentOf(bps);
    const ms = 30030; // 10000B / 333BPS * 1000;
    expect(transfer.msTotal).toBeWithin20PercentOf(ms);
    const msRemaining = 30030 - 300;
    expect(transfer.msRemaining).toBeWithin20PercentOf(msRemaining);

    return delay();
  });

  it('should transfer more data', () => {
    transfer.updateBytes(500);
    expect(transfer.started).toBe(true);
    expect(transfer.finished).toBe(false);
    expect(transfer.bytesCompleted).toBe(500);
    expect(transfer.bytesRemaining).toBe(9500);
    expect(transfer.bytesTotal).toBe(10000);
    expect(transfer.percentage).toBe(0.05);
    expect(transfer.msElapsed).toBeWithin20PercentOf(elapsedTime);
    const bps = 833; // 500B / 600MS * 1000;
    expect(transfer.bytesPerSecond).toBeWithin20PercentOf(bps);
    const ms = 12000; // 10000B / 833BPS * 1000;
    expect(transfer.msTotal).toBeWithin20PercentOf(ms);
    const msRemaining = 12000 - 600;
    expect(transfer.msRemaining).toBeWithin20PercentOf(msRemaining);

    return delay();
  });

  it('should transfer all the data', () => {
    transfer.updateBytes(10000);
    expect(transfer.started).toBe(true);
    expect(transfer.finished).toBe(false);
    expect(transfer.bytesCompleted).toBe(10000);
    expect(transfer.bytesRemaining).toBe(0);
    expect(transfer.bytesTotal).toBe(10000);
    expect(transfer.percentage).toBe(1);
    expect(transfer.msElapsed).toBeWithin20PercentOf(elapsedTime);
    const bps = 11111; // 10000B / 900MS * 1000;
    expect(transfer.bytesPerSecond).toBeWithin20PercentOf(bps);
    const ms = 900; // 10000B / 11111BPS * 1000;
    expect(transfer.msTotal).toBeWithin20PercentOf(ms);
    const msRemaining = 0;
    expect(transfer.msRemaining).toBe(msRemaining);

    return delay();
  });

  it('should be able to be marked as finished', () => {
    transfer.finish();
    expect(transfer.started).toBe(false);
    expect(transfer.finished).toBe(true);
  });
});