Pte or Pvt - Python

Pte (Python Test Environment) or Pvt (Python Virtual Time) is a Python package that provides a virtual time environment for testing time-based code. Pte provides an easy-to-use API that allows creating time-based scenarios and testing their behavior.

Installation

You can install Pte or Pvt using pip:

pip install pte

or

pip install pvt

Usage

To use Pte or Pvt, import the TimeEnvironment class and create a new instance:

from pte import TimeEnvironment

env = TimeEnvironment()

Alternatively, you can use the context manager to create a new instance:

from pte import timecontext

with timecontext() as env:
    pass

Patching time

You can patch time in the virtual environment using the patch_time method:

from pte import TimeEnvironment

env = TimeEnvironment()

current_time = env.time()
assert current_time == 0.0  # initial time is 0.0

env.patch_time(100.0)

assert env.time() == 100.0  # time is now 100.0

Creating scenarios

You can create time-based scenarios using the scenario method:

from pte import TimeEnvironment

env = TimeEnvironment()

def test_scenarios():
    with env.scenario() as scenario:
        scenario.sleep(1.0)
        assert env.time() == 1.0
        
        scenario.wait(lambda: env.time() >= 3.0)
        assert env.time() == 3.0
        
        scenario.sleep(2.0)
        assert env.time() == 5.0
        
    assert env.time() == 0.0

In the above example, we create a scenario in which we sleep for 1 second, wait until time is equal or greater than 3 seconds, sleep for another 2 seconds, and finally check that time has advanced to 5 seconds.

Time acceleration

You can accelerate time in the virtual environment using the accelerate_time method:

from pte import TimeEnvironment

env = TimeEnvironment()

env.accelerate_time(10.0)

env.sleep(1.0)
assert env.time() == 10.0  # sleeping for 1.0 second in real time is equivalent to 10.0 seconds in virtual time

Time mocking

You can mock the current time with the mock_time method:

from pte import TimeEnvironment

env = TimeEnvironment()

env.mock_time(100.0)

assert env.time() == 100.0  # time is now mocked to be 100.0

Freezing time

You can freeze time in the virtual environment with the freeze_time method:

from pte import TimeEnvironment

env = TimeEnvironment()

env.patch_time(100.0)

env.freeze_time()

env.sleep(1.0)
assert env.time() == 100.0  # time is frozen and does not advance

env.unfreeze_time()

env.sleep(1.0)
assert env.time() == 101.0  # time has advanced by 1.0 second

Conclusion

Pte or Pvt is a powerful tool for testing time-based code. With its easy-to-use API, you can create time-based scenarios, accelerate time, mock the current time, freeze time, and more.