anybox.testing.datetime 0.2.1

A module to allow playing with time in tests.

This README is also a doctest. To it and other doctests for this package, simply do:

nosetests --with-doctest --doctest-extension=txt

Before anything, the package must be imported in order to replace the regular datetime module with the modified one:

>>> import anybox.testing.datetime
>>> from datetime import datetime
>>> import time

Let’s keep the real value of now around:

>>> start = datetime.now()
>>> start_t = time.time()

Then you can:

>>> datetime.set_now(datetime(2001, 01, 01, 3, 57, 0))
>>> datetime.now()
datetime(2001, 1, 1, 3, 57)
>>> datetime.today()
datetime(2001, 1, 1, 3, 57)

The time module goes along:

>>> datetime.fromtimestamp(time.time())
datetime(2001, 1, 1, 3, 57)

Note that you can expect a few microseconds difference (not displayed here because datetime.fromtimestamp ignores them).

Don’t forget afterwards get back to the regular system clock, otherwise many pieces of code might get very suprised if the system clock looks as if it’s frozen:

>>> datetime.real_now()

Now let’s check it worked:

>>> now = datetime.now()
>>> now > start
True
>>> from datetime import timedelta
>>> now - start < timedelta(0, 0, 10000) # 10 ms
True

And with the time module:

>>> now_t = time.time()
>>> now_t > start_t
True
>>> now_t - start_t < 0.01 # 10 ms again
True

Other constructors are still available (this is a non regression test):

>>> import datetime
>>> datetime.time(3, 57, 0)
datetime.time(3, 57)
>>> datetime.datetime(2013, 1, 1, 3, 57, 0)
datetime(2013, 1, 1, 3, 57)
>>> datetime.date(2013, 1, 1)
datetime.date(2013, 1, 1)