datetimemocker

with DateTimeMocker():
    # datetime is mocked everywhere.

For examples, see the unittests at /datetimemocker/test/test_datetimemocker.py

Installation

1. Install the package:

   $ pip install datetimemocker

2. Import datetime and DateTimeMocker in your test file.

   # test.py
   from datetimemocker import DateTimeMocker
   import datetime

3. Define the datetime or date instance you wish to use as your mock value.

   def test():
       datetime_to_use = datetime.datetime(2016, 7, 8, 16, 0, 0)

4. Using the with context manager, pass the datetime instance you wish as your mock value.

   with DateTimeMocker(datetime_to_use=datetime_to_use):
       assert(...)

• Or pass a date instance to date_to_use:

  date_to_use = datetime.date(2016, 7, 8)
  with DateTimeMocker(date_to_use=date_to_use):
      assert(...)

API

The datetime module implements all of the following backend functions:

• instance_check()
• make_mock_date_time()
• make_mock_date()
• make_mock_date_time_module()

DateTimeMocker implements all of the following backend methods.

• __init__()
• __add_mocking_to_module()
• __enter__()
• __exit__()

How to use the DateTimeMocker keyword arguments to customize the mocked values.

DateTimeMocker.__init__(self, datetime_to_use=None, date_to_use=None, modules=None, search_for_modules=True)**:

Passing in a datetime instance to the datetime_to_use argument will set the datetime instance as the return value of datetime.now().

For example, with datetime_to_use set to datetime(2016, 7, 8, 13, 0, 5, 72, tzinfo=pytz.UTC):

datetime.now() returns 2016-07-08 13:00:05.000072+00:00 datetime.date.today() returns 2016-07-08

Likewise, pasing in a date instance to the date_to_use argument will set the date instance as the return value of datetime.today().

For example, with date_to_use set to datetime.date(2016, 7, 8): datetime.now() returns 2016-07-08 03:07:59.330384+00:00 datetime.date.today() returns 2016-07-08

Notice, however that the times are different in the two examples. When passing in a datetime instance, the time value of the datetime instance is applied to the mock as well. When passing in a date instance, however, the time portion of the datetime instance returned by datetime.now() is inherited from an newly-created instance, and so the time value is "now" (the time on the server) on the mocked date.

By default, the DateTimeMocker will mock all loaded modules with references to datetime. However, if you wish to restrict the mock to specific modules, you may pass them in as an iterable to the modules argument.

For example: with DateTimeMocker(datetime_to_use=datetime_to_use, modules=(module1, module2)):

This will only apply the mock to these two modules.

The search_for_modules argument is True by default. If True the DateTimeMocker will iterate through all modules loaded in the environment and apply the mock, except for the datetime modules and the current module.

How it works

Using the with context manager, instantiating a DateTimeMocker class will create mock datetime and date classes and a mock datetime module. Then the DateTimeMocker instance will iterate over a list of modules and mock all references to datetime or date with the mock module and classes. Upon exiting the context (un-indenting), the mocks will be stopped gracefully.