Learnings

<p>Effective TDD: Tricks to speed up Django tests (up to 10x faster!) </p>

<p><code>powerset</code> recipe from itertools is very useful for testing all cases of a function that accepts a list of choices: #itertools-recipes</p>

<p>Mocking image downloads for libs that actually check the file's contents, like Fleep </p>

<p>Use <code>django.test.override_settings</code> decorator to override specific settings for test methods</p>

<p>How to test if a logger is called: </p>

<p>Use python freezegun lib to freeze your dates when making tests</p>

<p>Custom context managers in Python unit tests for better fixtures: </p>

<p>If you set the parameter <code>side_effect</code> in <code>mock.patch()</code> as an iterable each call to the mock will return the next value from the iterable.</p>

<p>For tests use <code>assertCountEqual</code>, using two sequences it tests if the first contains the same elements as second, regardless of their order.</p>

<p>Need to use <code>tox</code> while using <code>pyenv</code>? Don't forget to use the packages <code>tox-pyenv</code> for <code>pyenv</code> support and <code>pyenv-implicit</code> to make it find the correct python executable.</p>

<p>To use querystring in urls when using <code>response</code> library for tests, remember to set <code>match_querystring=True</code> in your <code>add</code> method</p>

<p>If you are testing sending emails in your project and are using mock, use <code>call_args_list</code> method to see a list of all the calls made to the mock object in sequence: #unittest.mock.Mock.call_args_list</p>

<p>"acid test" for image scaling software: </p>

<p>Big List of Naughty Strings which have a high probability of causing issues when used as user-input data: </p>