Django template coverage.py plugin
A coverage.py_ plugin to measure test coverage of Django templates.
Supported on:
Python: 3.8 through 3.12.
Django: 2.x, 3.x and 4.x.
Coverage.py: 6.x or higher.
The plugin is pip installable::
$ python3 -m pip install django_coverage_plugin
To run it, add this setting to your .coveragerc file::
[run]
plugins = django_coverage_plugin
Then run your tests under coverage.py_.
You will see your templates listed in your coverage report along with
your Python modules. Please use coverage.py_ v4.4 or greater to allow
the plugin to identify untested templates.
If you get a :code:django.core.exceptions.ImproperlyConfigured error,
you need to set the :code:DJANGO_SETTINGS_MODULE environment variable.
Template coverage only works if your Django templates have debugging enabled.
If you get :code:django_coverage_plugin.plugin.DjangoTemplatePluginException: Template debugging must be enabled in settings, or if no templates get
measured, make sure you have :code:TEMPLATES.OPTIONS.debug set to True in
your settings file:
.. code-block:: python
TEMPLATES = [
{
...
'OPTIONS': {
'debug': True,
},
},
]
Configuration
The Django template plugin uses some existing settings from your
``.coveragerc`` file. The ``source=``, ``include=``, and ``omit=`` options
control what template files are included in the report.
The plugin can find unused template and include them in your results. By
default, it will look for files in your templates directory with an extension
of ``.html``, ``.htm``, or ``.txt``. You can configure it to look for a different set of
extensions if you like::
[run]
plugins = django_coverage_plugin
[django_coverage_plugin]
template_extensions = html, txt, tex, email
If you use ``pyproject.toml`` for tool configuration use::
[tool.coverage.run]
plugins = [
'django_coverage_plugin',
]
[tool.coverage.django_coverage_plugin]
template_extensions = 'html, txt, tex, email'
Caveats
~~~~~~~
Coverage.py can't tell whether a ``{% blocktrans %}`` tag used the
singular or plural text, so both are marked as used if the tag is used.
What the? How?
The technique used to measure the coverage is the same that Dmitry
Trofimov used in dtcov_, but integrated into coverage.py as a plugin,
and made more performant. I'd love to see how well it works in a real
production project. If you want to help me with it, feel free to drop me
an email.
The coverage.py plugin mechanism is designed to be generally useful for hooking into the collection and reporting phases of coverage.py, specifically to support non-Python files. If you have non-Python files you'd like to support in coverage.py, let's talk.
Tests
To run the tests::
$ python3 -m pip install -r requirements.txt
$ tox
History
.. scriv-insert-here
Dropped support for Python 3.7 and Django 1.x. Declared support for Python 3.12.
Dropped support for Python 2.7, Python 3.6, and Django 1.8.
Declare our support for Python 3.11 and Django 4.1.
Add support for Django 4.0.
If a non-UTF8 file was found when looking for templates, it would fail when
reading during the reporting phase, ending execution. This failure is now
raised in a way that can be ignored with a .coveragerc setting of [report] ignore_errors=True (issue 78_).
When using source=., an existing coverage HTML report directory would be
found and believed to be unmeasured HTML template files. This is now fixed.
.. _issue 78: https://github.com/nedbat/django_coverage_plugin/issues/78
Test and claim our support on Python 3.10.
Drop support for Python 3.4 and 3.5.
A setting is available: template_extensions lets you set the file
extensions that will be considered when looking for unused templates
(requested in issue 60_).
Fix an issue on Windows where file names were being compared
case-sensitively, causing templates to be missed (issue 46_).
Fix an issue (issue 63_) where tag libraries can't be found if imported
during test collection. Thanks to Daniel Izquierdo for the fix.
.. _issue 46: https://github.com/nedbat/django_coverage_plugin/issues/46 .. _issue 60: https://github.com/nedbat/django_coverage_plugin/issues/60 .. _issue 63: https://github.com/nedbat/django_coverage_plugin/issues/63
Add support for:
Add support for:
Add support for Django 2.1.
Validates support for Django version 2.0b1. Improves discovery of template files.
Validates support for Django version 1.11. Testing for new package maintainer Pamela McA'Nulty
Removes support for Django versions below 1.8. Validates support for Django version 1.11b1
Fixes another instance of issue 32_, which was the result of an
initialization order problem.
.. _issue 32: https://github.com/nedbat/django_coverage_plugin/issues/32
Fixes issue 32_, which was the result of an initialization order
problem.
Django 1.10.5 is now supported.
Checking settings configuration is deferred so that settings.py is
included in coverage reporting. Fixes issue 28_.
Only the django.template.backends.django.DjangoTemplates template
engine is supported, and it must be configured with
['OPTIONS']['debug'] = True. Fixes issue 27_.
.. _issue 28: https://github.com/nedbat/django_coverage_plugin/issues/28 .. _issue 27: https://github.com/nedbat/django_coverage_plugin/issues/27
Settings are read slightly differently, so as to not interfere with
programs that don't need settings. Fixes issue 18_.
.. _issue 18: https://github.com/nedbat/django_coverage_plugin/issues/18
Multiple template engines are allowed. Thanks, Simon Charette.
No change in code, but Django 1.9.2 is now supported.
The template debug settings are checked properly for people still using
TEMPLATE_DEBUG in newer versions of Django.
Check if template debugging is enabled in the settings, and raise a
visible warning if not. This prevents mysterious failures of the
plugin, and fixes issue 17_.
Potential Django 1.9 support is included, but the patch to Django hasn't been applied yet.
.. _issue 17: https://github.com/nedbat/django_coverage_plugin/issues/17
Explicitly configure settings if need be to get things to work.
First version :)
.. _coverage.py: http://nedbatchelder.com/code/coverage .. _dtcov: https://github.com/traff/dtcov