[damned-lies] Fix and test the help view

[Claude Paroz <claudep src gnome org>]

commit efe78c47349f5a3bd568e32c8c448188d5b380d1
Author: Claude Paroz <claude 2xlibre net>
Date:   Sat Dec 21 11:40:56 2019 +0100

    Fix and test the help view

 common/tests.py | 13 +++++++++++++
 common/views.py |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)
---
diff --git a/common/tests.py b/common/tests.py
index d41d42b6..6372a74e 100644
--- a/common/tests.py
+++ b/common/tests.py
@@ -6,6 +6,7 @@ from unittest.mock import MagicMock, patch
 from django.conf import settings
 from django.core.management import call_command
 from django.test import TestCase as DjangoTestCase
+from django.urls import reverse
 from django.utils import translation
 
 from people.models import Person
@@ -15,6 +16,18 @@ from .utils import lc_sorted, pyicu_present, trans_sort_object_list
 
 
 class CommonTest(DjangoTestCase):
+    def test_help_pages(self):
+        response = self.client.get(reverse('help', args=['reduced_po', 1]))
+        self.assertContains(response, '<div class="modal-body">')
+
+        response = self.client.get(reverse('help', args=['reduced_po', 0]))
+        self.assertNotContains(response, '<div class="modal-body">')
+
+        response = self.client.get(reverse('help', args=['reduced_po']))
+        self.assertNotContains(response, '<div class="modal-body">')
+
+        response = self.client.get(reverse('help', args=['unexisting', 1]))
+        self.assertEqual(response.status_code, 404)
 
     def test_house_keeping(self):
         pn = Person.objects.create(
diff --git a/common/views.py b/common/views.py
index 48ced4d9..24f60b80 100644
--- a/common/views.py
+++ b/common/views.py
@@ -99,7 +99,7 @@ def activate_account(request, key):
     return HttpResponseRedirect(reverse('login'))
 
 
-def help(request, topic, modal):
+def help(request, topic, modal=None):
     template = 'help/%s.html' % topic
     try:
         get_template(template)