Plugin will be disabled due to exception when extra engine is not django.template.backends.django.DjangoTemplates

When multiple template engines are used, django_coverage_plugin will check them all and raise DjangoTemplatePluginException which will cause it to be disabled by coverage. Instead, it should work for the DjangoTemplates engine and ignore the others.

SETTINGS.PY

TEMPLATES = [
    {
        # https://docs.djangoproject.com/en/dev/ref/settings/#std:setting-TEMPLATES-BACKEND
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        # https://docs.djangoproject.com/en/dev/ref/settings/#dirs
        "DIRS": [str(APPS_DIR / "templates")],
        # https://docs.djangoproject.com/en/dev/ref/settings/#app-dirs
        "APP_DIRS": True,
        "OPTIONS": {
            # https://docs.djangoproject.com/en/dev/ref/settings/#template-context-processors
            "context_processors": [
                "django.template.context_processors.debug",
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.template.context_processors.i18n",
                "django.template.context_processors.media",
                "django.template.context_processors.static",
                "django.template.context_processors.tz",
                "django.contrib.messages.context_processors.messages",
            ],
            "builtins": ["template_partials.templatetags.partials"],
        },
    },
    {
        "BACKEND": "post_office.template.backends.post_office.PostOfficeTemplates",
        "APP_DIRS": True,
        "DIRS": [],
        "OPTIONS": {
            "context_processors": [
                "django.contrib.auth.context_processors.auth",
                "django.template.context_processors.debug",
                "django.template.context_processors.i18n",
                "django.template.context_processors.media",
                "django.template.context_processors.static",
                "django.template.context_processors.tz",
                "django.template.context_processors.request",
            ],
        },
    },
]

TRACEBACK

/tmp/poetry_cache/virtualenvs/.venv/lib/python3.12/site-packages/coverage/inorout.py:378: CoverageWarning: Disabling plug-in 'django_coverage_plugin.DjangoTemplatePlugin' due to an exception:
Traceback (most recent call last):
File "/tmp/poetry_cache/virtualenvs/.venv/lib/python3.12/site-packages/coverage/inorout.py", line 363, in should_trace
file_tracer = plugin.file_tracer(canonical)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/tmp/poetry_cache/virtualenvs/.venv/lib/python3.12/site-packages/django_coverage_plugin/plugin.py", line 181, in file_tracer
self.debug_checked = check_debug()
^^^^^^^^^^^^^
File "/tmp/poetry_cache/virtualenvs/.venv/lib/python3.12/site-packages/django_coverage_plugin/plugin.py", line 88, in check_debug
raise DjangoTemplatePluginException(
django_coverage_plugin.plugin.DjangoTemplatePluginException: Can't use non-Django templates.

self.warn(f"Disabling plug-in {plugin_name!r} due to an exception:\n{tb}")

Read django_coverage_plugin/plugin.py, starting with file_tracer and check_debug, to see how multiple configured template engines are handled. Done means the DjangoTemplates engine remains supported while non-Django template engines are ignored without disabling the plugin; the payload does not name a test file.