global.Date not mocked when window.Date exists

[jfstephe]

Hi,

First off, thanks for this. It helped us be able to test some code with date_fns that would have been a nightmare otherwise.

The problem:

If you have UI tests running in node then you have a window object and a global. The code at:

timezone-mock/index.js

Lines 265 to 272 in 780f8c2

	function register(new_timezone, glob) {
	if (!glob) {
	if (typeof window !== 'undefined') {
	glob = window;
	} else {
	glob = global;
	}
	}

...assumes one or the other but not both.

As a workaround I'm doing:

timezoneMock.register(timezone);
global.Date = window.Date;

/// ...tests

timezoneMock.unregister();
global.Date = window.Date;

[Jimbly]

In your setup, do both window and global have a Date member, or only global?

If not both, probably an easy fix to check typeof window !== 'undefined' && window.Date, otherwise, if both, probably changing the flow to something like this would work (you could try hacking it up locally and report back and/or send a PR if it does):

function registerInternal(glob) {
  if (glob.Date !== MockDate) {
    _Date = glob.Date;
    exports._Date = glob.Date;
  }
  glob.Date = MockDate;
}

function register(new_timezone, glob) {
  timezone = new_timezone || 'US/Pacific';
  if (glob) {
    registerInternal(glob);
  } else {
    if (typeof window !== 'undefined') {
      registerInternal(window);
    }
    if (typeof global !== 'undefined') {
      registerInternal(global);
    }
  }
  if (!orig_object_toString) {
    orig_object_toString = Object.prototype.toString;
    Object.prototype.toString = mockDateObjectToString;
  }
}

[jfstephe]

Hi, thanks for the quick response!

Yes we have both Global (from node) and Window (from the UI test lib).

Strangely I've re-run this without my workaround and it's working, but this definitely was an issue and I think it makes sense that an issue is there. It could be a race condition somewhere in my code, not sure.

I did manage to run the code you suggested above and that continued to work. The unregister would need some tweaking too I think.

I'm not in a position to easily do a PR I'm afraid due to company restrictions. This isn't hurting me ATM and there's a workaround so maybe for vNext? At least it's recorded for others :-)

[Jimbly]

Yes we have both Global (from node) and Window (from the UI test lib).

I was wondering if the fake window your UI test lib is adding has a Date member (wouldn't be too surprising if it doesn't, since it's not needed for mocking testing UI stuff, but it might also put it there just for completeness...)? Could use a slightly different fix if it does or doesn't, though I guess register could be made to simply replace whichever Date it finds on either =).

Anyway, will leave this here, if someone else runs into a similar issue in the future they can try the fix and hopefully send a PR if it works =).