Unit test to validate django templates

test_django_template_syntax.py

"""Test templates for syntax errors."""
import os
import glob

from importlib import import_module

from django.conf import settings
from django.template import TemplateSyntaxError, Template


def test_templates():
    """Templates can compile properly and there's no mismatched tags"""
    # get app template dirs
    template_dirs = []
    apps = [app for app in settings.INSTALLED_APPS if app.startswith('my_app')]
    for app in apps:
        mod = import_module(app)
        template_dirs.append(os.path.join(os.path.dirname(mod.__file__), 'templates'))
    # get template dirs from settings
    for template in settings.TEMPLATES:
        for template_dir in template.get('DIRS'):
            template_dirs.append(template_dir)
    # find all templates (*.html and *.txt)
    templates = []
    for template_dir in template_dirs:
        templates += glob.glob('%s/*.html' % template_dir)
        templates += glob.glob('%s/*.txt' % template_dir)
        for root, dirnames, filenames in os.walk(template_dir):  # pylint: disable=unused-variable
            for dirname in dirnames:
                template_folder = os.path.join(root, dirname)
                templates += glob.glob('%s/*.html' % template_folder)
                templates += glob.glob('%s/*.txt' % template_folder)
    for template in templates:
        with open(template, 'r') as f:
            source = f.read()
            # template compilation fails on impaired or invalid blocks tags
            try:
                Template(source)
            except TemplateSyntaxError as e:
                raise TemplateSyntaxError('%s in %s' % (e, template))
            # check for badly formated tags or filters
            assert source.count('{%') == source.count('%}'), 'Found impaired {{% %}} in {}'.format(template)
            assert source.count('{{') == source.count('}}'), 'Found impaired {{ and }} in {}'.format(template)