Testing Extensions¶

Overview¶

To ensure that your extension works as expected and continues to work in the future, it’s recommended that your extension come with some unit tests.

Starting in Djblets 1.0, we make it much easier to write unit tests for your extension. Your extension will need to ship with two things: A set of test cases, and a test runner.

Writing Test Cases¶

Extension test cases can use a mixin, ExtensionTestCaseMixin, to set up and enable an extension instance to test against. This takes an extension class as a class attribute, and optionally allows custom metadata and a package name to be set. The individual tests can then make use of an extension instance.

For example:

from django.test import TestCase
from djblets.extensions.testing import ExtensionTestCaseMixin

from my_extension.extension import MyExtension


class MyExtensionTests(ExtensionTestCaseMixin, TestCase):
    extension_class = MyExtension

    def test_something(self):
        self.assertEqual(self.extension.some_call(), 'some value')

Extensions may want to create a base class that utilizes the mixins and sets the extension_class attribute, and subclass that for all individual test suites. For example:

from django.test import TestCase
from djblets.extensions.testing import ExtensionTestCaseMixin

from my_extension.extension import MyExtension


class MyExtensionTestCase(ExtensionTestCaseMixin, TestCase):
    extension_class = MyExtension


class MyExtensionTests(MyExtensionTestCase):
    def test_something(self):
        self.assertEqual(self.extension.some_call(), 'some value')

Writing a Test Runner¶

Your extension will also need a test runner. Djblets offers a handy one built-in that’s ready for extensions to use: djblets.testing.testrunners.TestRunner.

To make use of this, you’ll want to create a subclass with some state, set up your Django environment for your project, and invoke the test runner.

A test runner script might look like:

#!/usr/bin/env python

import os
import sys

os.environ['DJANGO_SETTINGS_MODULE'] = 'myapp.settings'

from djblets.testing.testrunners import TestRunner

test_runner = TestRunner(test_packages=['my_extension'])

# Run the test suite, passing any specific test names to run that the
# user may have specified on the command line.
failures = test_runner.run_tests(sys.argv[1:])

if failures:
    sys.exit(1)

A couple things to note:

1. You’ll need to adjust this to point to the correct Django settings module for the project that uses the extension, and you also may need to set up other state for the environment (for example, the project might require a settings_local.py or similar that contains database settings or other such data).
2. The project you’re developing extensions for may have its own specialized test runner to use that sets up additional stuff for you. Follow the project’s documentation.