We have multiple resources for writing new unit tests for Django, Wagtail, and Python code:
- CFPB Django and Wagtail unit testing documentation
- The Django testing documentation
- The Wagtail testing documentation
- Real Python's "Testing in Django"
When writing tests that rely on a running Elasticsearch service, consider using the
from django.test import TestCase from search.elasticsearch_helpers import ElasticsearchTestsMixin class MyTests(ElasticsearchTestsMixin, TestCase): def test_something(self): self.rebuild_elasticsearch_index() # test something that relies on the Elasticsearch index
Refer to the mixin's source code for additional details on its functionality.
If you have not set up the standalone installation of consumerfinance.gov, you can still run the tests if you install Tox in your local installation of Python:
pip install tox
If you have set up a Docker-based installation of consumerfinance.gov, you can run the tests there by accessing the Python container's shell:
docker-compose exec python sh
Our test suite can either be run in a local virtualenv or in Docker. Please note, the tests run quite slow in Docker.
To run the the full suite of Python tests using Tox, make sure you are in the consumerfinance.gov root and then run:
Tox runs different isolated Python environments with different versions of dependencies. We use it to format and lint our Python files, check out import sorting, and run unit tests in Python 3.8.
To recreate the virtualenv for testing, run
For additional information on tox arguments, refer to the tox documentation
You can select specific environments using
tox by itself is the same as running:
tox -e lint -e unittest
These default environments are:
lint, which runs our linters. We require this environment to pass in CI.
validate-migrations, which checks for any missing Django migrations. We require this environment to pass in CI.
unittest, which runs unit tests against the current production versions of Python, Django, and Wagtail. We require this environment to pass in CI.
Tests will run against the default Django database.
If you would like to run only a specific test, or the tests for a specific app,
you can provide a dotted path to the test as the final argument to any of the above calls to
tox -e unittest regulations3k.tests.test_regdown
If you would like to skip running Django migrations when testing, set the
SKIP_DJANGO_MIGRATIONS environment variable to any value before running
black to autoformat our Python code.
black is invoked by Tox using
lint environment (this will also run
tox -e lint
It is highly recommended to only invoke black via tox
We also use Bandit to find any common security issues in our Python code.
bandit can all be run using the Tox
(this will also run
tox -e lint
This will run
isort in check-only mode and it will print diffs for imports
that need to be fixed. To automatically fix import sort issues, run:
isort --recursive cfgov/
From the root of
To see Python code coverage information immediately following a test run,
you can add the
coverage env to the list of envs for tox to run:
tox -e lint -e unittest -e coverage
You can also run coverage directly to see coverage information from a previous test run:
coverage report -m
To see coverage for a limited number of files,
--include argument to
coverage and provide a path to the files you wish to see:
coverage report -m --include=./cfgov/regulations3k/*
Python tests should avoid writing to stdout as part of their normal execution.
To enforce this convention, the tests can be run using a custom Django test
runner that fails if anything is written to stdout. This test runner is at
cfgov.test.StdoutCapturingTestRunner and can be enabled with the
TEST_RUNNER=core.testutils.runners.StdoutCapturingTestRunner tox -e unittest
This test runner is enabled when tests are run automatically on GitHub Actions, but is not used by default when running tests locally.
If you write Python code that interacts with the GovDelivery subscription API, you can use the functionality provided in
core.govdelivery.MockGovDelivery as a mock interface to avoid the use of
patch in unit tests.
This object behaves similarly to the real
govdelivery.api.GovDelivery class in that it handles all requests and returns a valid (200)
Conveniently for unit testing, all calls are stored in a class-level list that can be retrieved at
MockGovDelivery.calls. This allows for testing of code that interacts with GovDelivery by checking the contents of this list to ensure that the right methods were called.
This pattern is modeled after Django's
django.core.mail.outbox which provides similar functionality for testing sending of emails.
The related classes
ServerErrorMockGovDelivery can similarly be used in unit tests to test for cases where a call to the GovDelivery API raises an exception and returns an HTTP status code of 500, respectively.