zurvan/tests/DateInterceptorTests.js

A library for simulating time in Node.js

'use strict';
var TimeUnit = require('../TimeUnit');
var TypeChecks = require('../detail/utils/TypeChecks');
var zurvan = require('../zurvan');

var assert = require('assert');

describe('zurvan', function() {
  describe('when faking Date', function() {
    beforeEach(function() {
      return zurvan.interceptTimers();
    });
    afterEach(function() {
      return zurvan.releaseTimers();
    });

    it('intercepts Date and by default resets timestamp to 0', function(done) {
      var now = Date.now();
      var nowDate = new Date();

      assert.equal(now, 0);
      assert.equal(nowDate.toISOString(), '1970-01-01T00:00:00.000Z');
      done();
    });

    it('behaves the same as original in all cases that do not require referring to current time', function(done) {
      var orig = new Date(0);
      var now = new Date();

      assert.equal(orig.toISOString(), now.toISOString());
      done();
    });

    it('adjusts to how far time is moved', function(done) {
      zurvan
        .advanceTime(TimeUnit.days(10))
        .then(function() {
          var nowDate = new Date();
          assert.equal(nowDate.toISOString(), '1970-01-11T00:00:00.000Z');
          return zurvan.advanceTime(TimeUnit.nanoseconds(17e9 + 673e6));
        })
        .then(function() {
          var nowDate = new Date();
          assert.equal(nowDate.toISOString(), '1970-01-11T00:00:17.673Z');
          return zurvan.advanceTime(TimeUnit.minutes(86));
        })
        .then(function() {
          var nowDate = new Date();
          var origFromString = new Date(Date.UTC(2020, 3, 5, 2, 5, 6, 78));

          assert.equal(nowDate.toISOString(), '1970-01-11T01:26:17.673Z');
          assert.equal(
            origFromString.toISOString(),
            '2020-04-05T02:05:06.078Z'
          );

          var origFromWhole = new Date(1995, 4, 1, 9, 12, 5, 854);
          assert.equal(origFromWhole.getFullYear(), 1995);
          assert.equal(origFromWhole.getMonth(), 4);
          assert.equal(origFromWhole.getDate(), 1);
          assert.equal(origFromWhole.getHours(), 9);
          assert.equal(origFromWhole.getMinutes(), 12);
          assert.equal(origFromWhole.getSeconds(), 5);
          assert.equal(origFromWhole.getMilliseconds(), 854);
        })
        .then(function() {})
        .then(done, done);
    });

    it('allows Date to be called as function as in original', function(done) {
      var date = Date();
      assert(TypeChecks.isString(date));

      var dateObj = new Date(date);
      assert(TypeChecks.isObject(dateObj));
      done();
    });

    it('makes it possible to set system timer to arbitrary date', function(done) {
      zurvan.setSystemTime(new Date(Date.UTC(2010, 5, 6, 2, 1, 3)));
      var nowDate = new Date();

      assert.equal(nowDate.toISOString(), '2010-06-06T02:01:03.000Z');
      done();
    });

    it('makes it possible to set system timer to arbitrary date from parseable string', function(done) {
      zurvan.setSystemTime(
        new Date(Date.UTC(2005, 5, 6, 2, 1, 3)).toISOString()
      );
      var nowDate = new Date();

      assert.equal(nowDate.toISOString(), '2005-06-06T02:01:03.000Z');
      done();
    });

    it('makes it possible to set system timer to arbitrary date from timestamp', function(done) {
      zurvan.setSystemTime(Date.UTC(2005, 5, 13, 2, 1, 3));
      var nowDate = new Date();

      assert.equal(nowDate.toISOString(), '2005-06-13T02:01:03.000Z');
      done();
    });

    it('properly synchronizes system timer even if changed after startup', function(done) {
      zurvan
        .advanceTime(TimeUnit.days(10))
        .then(function() {
          zurvan.setSystemTime(Date.UTC(1990, 1, 1));
          var nowDate = new Date();
          assert.equal(nowDate.toISOString(), '1990-02-01T00:00:00.000Z');

          setTimeout(function() {
            var nowDate = new Date();
            assert.equal(nowDate.toISOString(), '1990-02-01T01:00:00.000Z');
          }, TimeUnit.hours(1).toMilliseconds());

          return zurvan.advanceTime(TimeUnit.days(10));
        })
        .then(function() {
          var nowDate = new Date();
          assert.equal(nowDate.toISOString(), '1990-02-11T00:00:00.000Z');
        })
        .then(done, done);
    });
  });
});