DateTime parse without date not working properly

[ilyakuzmin]

> DateTime.current
Mon, 16 May 2022 16:00:00 +0300

> DateTime.now_without_mock_time
Thu, 02 Nov 2023 03:04:10 +0300

> DateTime.parse('15:00:00')
Tue, 17 May 2022 15:00:00 +0000

I assume it's about round for TimeStackItem#travel_offset_days

Or need one more case for parse_with_mock_date

> DateTime._parse('15:00:00')
{:hour=>15, :min=>0, :sec=>0}

[joshuacronemeyer]

Seems like you have a good handle on this. Can you create a PR?

[joshuacronemeyer]

Was thinking about this and wanted to see more test cases. Seems like the correct behavior is to keep the Date part and only change the time

3.0.1 :002 > Time.now
 => 2023-11-02 07:30:29.518102 -0700
3.0.1 :003 > DateTime.parse('06:00:00')
 => Thu, 02 Nov 2023 06:00:00 +0000
3.0.1 :004 > DateTime.parse('01:00:00')
 => Thu, 02 Nov 2023 01:00:00 +0000
3.0.1 :005 > DateTime.parse('15:00:00')
 => Thu, 02 Nov 2023 15:00:00 +0000

[ilyakuzmin]

It depends on frozen time you use. Not sure what we can do with all this case in parse_with_mock_date, too much variations

case 1 correct

> Time.now
2022-08-02 09:50:00 +0300

> DateTime.parse("15:00:00")
Tue, 02 Aug 2022 15:00:00 +0000

> Timecop.top_stack_item
#<Timecop::TimeStackItem:... @travel_offset=-39521870.819318704

> 39521870.0 / 60 / 60 / 24
457.429050925926

> Timecop.top_stack_item.travel_offset_days
-457

case 2 incorrect

> Time.now
2022-08-02 05:50:00 +0300

> DateTime.parse("15:00:00")
Mon, 01 Aug 2022 15:00:00 +0000

> Timecop.top_stack_item
#<Timecop::TimeStackItem:... @travel_offset=-39536896.712171

> 39536896.0 / 60 / 60 / 24
457.602962962963

> Timecop.top_stack_item.travel_offset_days
-458

[joshuacronemeyer]

@ilyakuzmin does this fix it?

#415

[joshuacronemeyer]

I am going to merge that fix. Please reopen @ilyakuzmin if this issue is not fixed on main