Let your Python tests travel through time

Related tags

Testingfreezegun
Overview

FreezeGun: Let your Python tests travel through time

https://secure.travis-ci.org/spulec/freezegun.svg?branch=master https://coveralls.io/repos/spulec/freezegun/badge.svg?branch=master

FreezeGun is a library that allows your Python tests to travel through time by mocking the datetime module.

Usage

Once the decorator or context manager have been invoked, all calls to datetime.datetime.now(), datetime.datetime.utcnow(), datetime.date.today(), time.time(), time.localtime(), time.gmtime(), and time.strftime() will return the time that has been frozen. time.monotonic() will also be frozen, but as usual it makes no guarantees about its absolute value, only its changes over time.

Decorator

from freezegun import freeze_time
import datetime
import unittest

# Freeze time for a pytest style test:

@freeze_time("2012-01-14")
def test():
    assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)

# Or a unittest TestCase - freezes for every test, from the start of setUpClass to the end of tearDownClass

@freeze_time("1955-11-12")
class MyTests(unittest.TestCase):
    def test_the_class(self):
        assert datetime.datetime.now() == datetime.datetime(1955, 11, 12)

# Or any other class - freezes around each callable (may not work in every case)

@freeze_time("2012-01-14")
class Tester(object):
    def test_the_class(self):
        assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)

# Or method decorator, might also pass frozen time object as kwarg

class TestUnitTestMethodDecorator(unittest.TestCase):
    @freeze_time('2013-04-09')
    def test_method_decorator_works_on_unittest(self):
        self.assertEqual(datetime.date(2013, 4, 9), datetime.date.today())

    @freeze_time('2013-04-09', as_kwarg='frozen_time')
    def test_method_decorator_works_on_unittest(self, frozen_time):
        self.assertEqual(datetime.date(2013, 4, 9), datetime.date.today())
        self.assertEqual(datetime.date(2013, 4, 9), frozen_time.time_to_freeze.today())

    @freeze_time('2013-04-09', as_kwarg='hello')
    def test_method_decorator_works_on_unittest(self, **kwargs):
        self.assertEqual(datetime.date(2013, 4, 9), datetime.date.today())
        self.assertEqual(datetime.date(2013, 4, 9), kwargs.get('hello').time_to_freeze.today())

Context manager

from freezegun import freeze_time

def test():
    assert datetime.datetime.now() != datetime.datetime(2012, 1, 14)
    with freeze_time("2012-01-14"):
        assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)
    assert datetime.datetime.now() != datetime.datetime(2012, 1, 14)

Raw use

from freezegun import freeze_time

freezer = freeze_time("2012-01-14 12:00:01")
freezer.start()
assert datetime.datetime.now() == datetime.datetime(2012, 1, 14, 12, 0, 1)
freezer.stop()

Timezones

from freezegun import freeze_time

@freeze_time("2012-01-14 03:21:34", tz_offset=-4)
def test():
    assert datetime.datetime.utcnow() == datetime.datetime(2012, 1, 14, 3, 21, 34)
    assert datetime.datetime.now() == datetime.datetime(2012, 1, 13, 23, 21, 34)

    # datetime.date.today() uses local time
    assert datetime.date.today() == datetime.date(2012, 1, 13)

@freeze_time("2012-01-14 03:21:34", tz_offset=-datetime.timedelta(hours=3, minutes=30))
def test_timedelta_offset():
    assert datetime.datetime.now() == datetime.datetime(2012, 1, 13, 23, 51, 34)

Nice inputs

FreezeGun uses dateutil behind the scenes so you can have nice-looking datetimes.

@freeze_time("Jan 14th, 2012")
def test_nice_datetime():
    assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)

Function and generator objects

FreezeGun is able to handle function and generator objects.

def test_lambda():
    with freeze_time(lambda: datetime.datetime(2012, 1, 14)):
        assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)

def test_generator():
    datetimes = (datetime.datetime(year, 1, 1) for year in range(2010, 2012))

    with freeze_time(datetimes):
        assert datetime.datetime.now() == datetime.datetime(2010, 1, 1)

    with freeze_time(datetimes):
        assert datetime.datetime.now() == datetime.datetime(2011, 1, 1)

    # The next call to freeze_time(datetimes) would raise a StopIteration exception.

tick argument

FreezeGun has an additional tick argument which will restart time at the given value, but then time will keep ticking. This is alternative to the default parameters which will keep time stopped.

@freeze_time("Jan 14th, 2020", tick=True)
def test_nice_datetime():
    assert datetime.datetime.now() > datetime.datetime(2020, 1, 14)

auto_tick_seconds argument

FreezeGun has an additional auto_tick_seconds argument which will autoincrement the value every time by the given amount from the start value. This is alternative to the default parameters which will keep time stopped. Note that given auto_tick_seconds the tick parameter will be ignored.

@freeze_time("Jan 14th, 2020", auto_tick_seconds=15)
def test_nice_datetime():
    first_time = datetime.datetime.now()
    auto_incremented_time = datetime.datetime.now()
    assert first_time + datetime.timedelta(seconds=15) == auto_incremented_time

Manual ticks

FreezeGun allows for the time to be manually forwarded as well.

def test_manual_tick():
    initial_datetime = datetime.datetime(year=1, month=7, day=12,
                                        hour=15, minute=6, second=3)
    with freeze_time(initial_datetime) as frozen_datetime:
        assert frozen_datetime() == initial_datetime

        frozen_datetime.tick()
        initial_datetime += datetime.timedelta(seconds=1)
        assert frozen_datetime() == initial_datetime

        frozen_datetime.tick(delta=datetime.timedelta(seconds=10))
        initial_datetime += datetime.timedelta(seconds=10)
        assert frozen_datetime() == initial_datetime
def test_monotonic_manual_tick():
    initial_datetime = datetime.datetime(year=1, month=7, day=12,
                                        hour=15, minute=6, second=3)
    with freeze_time(initial_datetime) as frozen_datetime:
        monotonic_t0 = time.monotonic()
        frozen_datetime.tick(1.0)
        monotonic_t1 = time.monotonic()
        assert monotonic_t1 == monotonic_t0 + 1.0

Moving time to specify datetime

FreezeGun allows moving time to specific dates.

def test_move_to():
    initial_datetime = datetime.datetime(year=1, month=7, day=12,
                                        hour=15, minute=6, second=3)

    other_datetime = datetime.datetime(year=2, month=8, day=13,
                                        hour=14, minute=5, second=0)
    with freeze_time(initial_datetime) as frozen_datetime:
        assert frozen_datetime() == initial_datetime

        frozen_datetime.move_to(other_datetime)
        assert frozen_datetime() == other_datetime

        frozen_datetime.move_to(initial_datetime)
        assert frozen_datetime() == initial_datetime


@freeze_time("2012-01-14", as_arg=True)
def test(frozen_time):
    assert datetime.datetime.now() == datetime.datetime(2012, 1, 14)
    frozen_time.move_to("2014-02-12")
    assert datetime.datetime.now() == datetime.datetime(2014, 2, 12)

Parameter for move_to can be any valid freeze_time date (string, date, datetime).

Default arguments

Note that FreezeGun will not modify default arguments. The following code will print the current date. See here for why.

from freezegun import freeze_time
import datetime as dt

def test(default=dt.date.today()):
    print(default)

with freeze_time('2000-1-1'):
    test()

Installation

To install FreezeGun, simply:

$ pip install freezegun

On Debian systems:

$ sudo apt-get install python-freezegun

Ignore packages

Sometimes it's desired to ignore FreezeGun behaviour for particular packages (i.e. libraries). It's possible to ignore them for a single invocation:

from freezegun import freeze_time

with freeze_time('2020-10-06', ignore=['threading']):
    # ...

By default FreezeGun ignores following packages:

[
    'nose.plugins',
    'six.moves',
    'django.utils.six.moves',
    'google.gax',
    'threading',
    'Queue',
    'selenium',
    '_pytest.terminal.',
    '_pytest.runner.',
    'gi',
]

It's possible to set your own default ignore list:

import freezegun

freezegun.configure(default_ignore_list=['threading', 'tensorflow'])

Please note this will override default ignore list. If you want to extend existing defaults please use:

import freezegun

freezegun.configure(extend_ignore_list=['tensorflow'])
Owner
Steve Pulec
Steve Pulec
Android automation project with pytest+appium

Android automation project with pytest+appium

1 Oct 28, 2021
A simple Python script I wrote that scrapes NASA's James Webb Space Telescope tracker website using Selenium and returns its current status and location.

A simple Python script I wrote that scrapes NASA's James Webb Space Telescope tracker website using Selenium and returns its current status and location.

9 Feb 10, 2022
Hamcrest matchers for Python

PyHamcrest Introduction PyHamcrest is a framework for writing matcher objects, allowing you to declaratively define "match" rules. There are a number

Hamcrest 684 Dec 29, 2022
An Instagram bot that can mass text users, receive and read a text, and store it somewhere with user details.

Instagram Bot 🤖 July 14, 2021 Overview 👍 A multifunctionality automated instagram bot that can mass text users, receive and read a message and store

Abhilash Datta 14 Dec 06, 2022
Lightweight, scriptable browser as a service with an HTTP API

Splash - A javascript rendering service Splash is a javascript rendering service with an HTTP API. It's a lightweight browser with an HTTP API, implem

Scrapinghub 3.8k Jan 03, 2023
Divide full port scan results and use it for targeted Nmap runs

Divide Et Impera And Scan (and also merge the scan results) DivideAndScan is used to efficiently automate port scanning routine by splitting it into 3

snovvcrash 226 Dec 30, 2022
API Rest testing FastAPI + SQLAchmey + Docker

Transactions API Rest Implement and design a simple REST API Description We need to a simple API that allow us to register users' transactions and hav

TxeMac 2 Jun 30, 2022
An AWS Pentesting tool that lets you use one-liner commands to backdoor an AWS account's resources with a rogue AWS account - or share the resources with the entire internet 😈

An AWS Pentesting tool that lets you use one-liner commands to backdoor an AWS account's resources with a rogue AWS account - or share the resources with the entire internet 😈

Brandon Galbraith 276 Mar 03, 2021
Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source.

Mockoon Mockoon is the easiest and quickest way to run mock APIs locally. No remote deployment, no account required, open source. It has been built wi

mockoon 4.4k Dec 30, 2022
Docker-based integration tests

Docker-based integration tests Description Simple pytest fixtures that help you write integration tests with Docker and docker-compose. Specify all ne

Avast 326 Dec 27, 2022
A small automated test structure using python to test *.cpp codes

Get Started Insert C++ Codes Add Test Code Run Test Samples Check Coverages Insert C++ Codes you can easily add c++ files in /inputs directory there i

Alireza Zahiri 2 Aug 03, 2022
The Social-Engineer Toolkit (SET) repository from TrustedSec - All new versions of SET will be deployed here.

💼 The Social-Engineer Toolkit (SET) 💼 Copyright 2020 The Social-Engineer Toolkit (SET) Written by: David Kennedy (ReL1K) @HackingDave Company: Trust

trustedsec 8.4k Dec 31, 2022
Show surprise when tests are passing

pytest-pikachu pytest-pikachu prints ascii art of Surprised Pikachu when all tests pass. Installation $ pip install pytest-pikachu Usage Pass the --p

Charlie Hornsby 13 Apr 15, 2022
Asyncio http mocking. Similar to the responses library used for 'requests'

aresponses an asyncio testing server for mocking external services Features Fast mocks using actual network connections allows mocking some types of n

93 Nov 16, 2022
Generate random test credit card numbers for testing, validation and/or verification purposes.

Generate random test credit card numbers for testing, validation and/or verification purposes.

Dark Hunter 141 5 Nov 14, 2022
Test python asyncio-based code with ease.

aiounittest Info The aiounittest is a helper library to ease of your pain (and boilerplate), when writing a test of the asynchronous code (asyncio). Y

Krzysztof Warunek 55 Oct 30, 2022
Code coverage measurement for Python

Coverage.py Code coverage testing for Python. Coverage.py measures code coverage, typically during test execution. It uses the code analysis tools and

Ned Batchelder 2.3k Jan 04, 2023
Testing - Instrumenting Sanic framework with Opentelemetry

sanic-otel-splunk Testing - Instrumenting Sanic framework with Opentelemetry Test with python 3.8.10, sanic 20.12.2 Step to instrument pip install -r

Donler 1 Nov 26, 2021
A wrapper for webdriver that is a jumping off point for web automation.

Webdriver Automation Plus ===================================== Description: Tests the user can save messages then find them in search and Saved items

1 Nov 08, 2021
pytest plugin for testing mypy types, stubs, and plugins

pytest plugin for testing mypy types, stubs, and plugins Installation This package is available on PyPI pip install pytest-mypy-plugins and conda-forg

TypedDjango 74 Dec 31, 2022