Date.strptime returns wrong month for %Y

[krzyzak]

Hey,

Today I found issue with Date.strptime: it falls back to current month, rather than returning Jan 1st, when parsing just %Y:

Date.strptime('2000', "%Y")
=> Sat, 01 Jan 2000
require 'timecop'
=> true
Date.strptime('2000', "%Y")
=> Tue, 01 Feb 2000

Seems that the issue lies in time_extensions.rb.

[joshuacronemeyer]

thanks for the bug report @krzyzak are you interested in sending a PR with tests that demonstrate the fix?

[augustoccesar]

I was looking into opening a PR for this issue, but from the short investigation that I did it seems that this is a very explicit expected behaviour.

timecop/lib/timecop/time_extensions.rb

Lines 53 to 56 in 8ca1018

	d = Date._strptime(str, fmt) || Date.strptime_without_mock_date(str, fmt)
	now = Time.now.to_date
	year = d[:year] || now.year
	mon = d[:mon] || now.mon

I guess to change to the expected behaviour described in this issue it would need to change to something like

d = Date._strptime(str, fmt) || Date.strptime_without_mock_date(str, fmt)
now = Time.now.to_date
year = d[:year] || now.year
mon = d[:mon] || 1

which feels like a large change from the perspective of expectation of how this method works (on timecop).

So I think that the main question is: Should the timecop Date.strptime behaves like the Ruby Date.strptime, or this an expected/desired behaviour to default to the current month?

[joshuacronemeyer]

Thanks guys. The Timecop implementation of strptime is a work in progress. Our implementation is incomplete and we're slowly chipping away at it. It should behave like the ruby implementation.

checkout

timecop/test/date_strptime_scenarios.rb

Lines 68 to 81 in 8ca1018

	#TODO Support these formats
	# '%G %V %w',
	# '%G %V %u',
	# '%C %g %V %w',
	# '%C %g %V %u',
	# '%Y %U %w',
	# '%Y %U %u',
	# '%Y %W %w',
	# '%Y %W %u',
	# '%C %y %U %w',
	# '%C %y %U %u',
	# '%C %y %W %w',
	# '%C %y %W %u',

to see a bunch of time format stuff we haven't handled yet. The scenario highlighted by this issue is just one more to add to that list.

[joshuacronemeyer]

@krzyzak and @augustoccesar i'd appreciate if you'd have a look at my PR #379 for this issue. I'm open to suggestions on ways to better implement this.

[krzyzak]

@joshuacronemeyer yes, that indeed fixes my issue. Is there an option to release new gem version?

[joshuacronemeyer]

@krzyzak thanks for asking. I just released 0.9.5 that includes this change. Would appreciate you bumping your version and testing.