Better handle activities you can't apply to

Instead of a 404, we should just inform users of the endpoints that *do*
support applications.

ws/models.py

@@ -817,7 +817,7 @@ class BaseRating(models.Model):
     notes = models.TextField(max_length=500, blank=True)  # Contingencies, etc.
 
     @property
-    def activity_enum(self):
+    def activity_enum(self) -> enums.Activity:
         return enums.Activity(self.activity)
 
     def __str__(self):
@@ -1674,7 +1674,7 @@ def can_reapply(cls, latest_application):
         return time_passed > timedelta(days=waiting_period_days)
 
     @property
-    def activity(self):
+    def activity(self) -> str:
         """Extract the activity name from the class name/db_name.
 
         Meant to be used by inheriting classes, for example:

ws/templates/leaders/apply_any_activity.html

@@ -0,0 +1,28 @@
+{% extends "base.html" %}
+{% load application_tags %}
+{% load crispy_forms_tags %}
+
+{% block head_title %}Apply to be a leader{% endblock head_title %}
+
+{% block content %}
+{{ block.super }}
+
+<h1>Become a MITOC leader</h1>
+
+<p class="lead">
+  MITOC's volunteer leaders run trips for the community.
+</p>
+
+<p>
+  MITOCers may apply to become a leader, at the discretion of the activity chair(s).
+</p>
+
+Activities which accept leader applications:
+<ul>
+{% for activity_enum in activities_accepting_applications %}
+  <li><a href="{% url 'become_leader' activity_enum.value %}">{{ activity_enum.label}}</a></li>
+{% endfor %}
+</ul>
+
+
+{% endblock content %}

ws/tests/views/test_applications.py

@@ -1,4 +1,7 @@
+from unittest import mock
+
 from bs4 import BeautifulSoup
+from django.contrib import messages
 from django.contrib.auth.models import Group
 from django.test import Client, TestCase
 from freezegun import freeze_time
@@ -127,7 +130,63 @@ class BikingLeaderApplicationTest(TestCase):
     def test_404(self):
         self.client.force_login(factories.ParticipantFactory.create().user)
         response = self.client.get('/biking/leaders/apply/')
-        self.assertEqual(response.status_code, 404)
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.url, "/leaders/apply/")
+
+
+class AnyActivityLeaderApplyViewTest(TestCase):
+    def test_anonymous_user_can_see_page(self):
+        response = self.client.get('/leaders/apply/')
+        self.assertEqual(response.status_code, 200)
+        self.assertIn(
+            b"MITOC's volunteer leaders run trips for the community",
+            response.content,
+        )
+        # 3 activities (at time of writing) which accept applications
+        self.assertIn(b"Climbing", response.content)
+        self.assertIn(b"/climbing/leaders/apply/", response.content)
+        self.assertIn(b"Hiking", response.content)
+        self.assertIn(b"/hiking/leaders/apply/", response.content)
+        self.assertIn(b"Winter School", response.content)
+        self.assertIn(b"/winter_school/leaders/apply/", response.content)
+
+    def test_redirected_from_unknown_activity(self):
+        self.client.force_login(factories.ParticipantFactory.create().user)
+        with mock.patch.object(messages, 'error', wraps=messages.error) as msg_error:
+            response = self.client.get('/raccoon_wrestling/leaders/apply/')
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.url, "/leaders/apply/")
+        msg_error.assert_called_once_with(
+            mock.ANY, 'raccoon_wrestling is not a known activity.'
+        )
+
+    def test_redirected_from_activity_without_application(self):
+        self.client.force_login(factories.ParticipantFactory.create().user)
+        with mock.patch.object(messages, 'error', wraps=messages.error) as msg_error:
+            response = self.client.get('/cabin/leaders/apply/')
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.url, "/leaders/apply/")
+        msg_error.assert_called_once_with(
+            mock.ANY, 'Cabin is not accepting leader applications'
+        )
+
+    def test_no_underscores(self):
+        """Reproduces a somewhat odd case where stripping underscores led to a 500.
+
+        This was because our usual "activity is valid" checks first stripped underscores,
+        but then `winterschool` was expected to be a valid enum value & was not.
+        """
+        self.client.force_login(factories.ParticipantFactory.create().user)
+        with mock.patch.object(messages, 'error', wraps=messages.error) as msg_error:
+            response = self.client.get('/winterschool/leaders/apply/')
+        self.assertEqual(response.status_code, 302)
+        self.assertEqual(response.url, "/leaders/apply/")
+        msg_error.assert_called_once_with(
+            mock.ANY, 'winterschool is not a known activity.'
+        )
+        self.assertIn(
+            b"/winter_school/leaders/apply/", self.client.get(response.url).content
+        )
 
 
 class HikingLeaderApplicationTest(TestCase, Helpers):

ws/urls.py

@@ -169,8 +169,8 @@
     path('profile/edit/', views.EditProfileView.as_view(), name='edit_profile'),
     path(
         'leaders/apply/',
-        RedirectView.as_view(url='/winter_school/leaders/apply', permanent=True),
-        name='old_become_leader',
+        views.AnyActivityLeaderApplyView.as_view(),
+        name='leaders_apply',
     ),
     path('profile/membership/', views.PayDuesView.as_view(), name='pay_dues'),
     path('profile/waiver/', views.SignWaiverView.as_view(), name='initiate_waiver'),

ws/views/applications.py

@@ -16,10 +16,10 @@
 from django.db.models.functions import Cast, Least
 from django.forms.models import model_to_dict
 from django.http import Http404
-from django.shortcuts import render
+from django.shortcuts import redirect, render
 from django.urls import reverse, reverse_lazy
 from django.utils.decorators import method_decorator
-from django.views.generic import CreateView, DetailView, ListView
+from django.views.generic import CreateView, DetailView, ListView, TemplateView
 from django.views.generic.edit import FormMixin
 
 import ws.utils.perms as perm_utils
@@ -144,11 +144,35 @@ def get_context_data(self, **kwargs):
     @method_decorator(user_info_required)
     def dispatch(self, request, *args, **kwargs):
         activity = kwargs.get('activity')
-        if not models.LeaderApplication.can_apply_for_activity(activity):
-            raise Http404
+        try:
+            activity_enum = enums.Activity(activity)
+        except ValueError:  # (Not a valid activity)
+            messages.error(self.request, f"{activity} is not a known activity.")
+            return redirect(reverse('leaders_apply'))
+
+        if not models.LeaderApplication.can_apply_for_activity(activity_enum):
+            messages.error(
+                self.request,
+                f"{activity_enum.label} is not accepting leader applications",
+            )
+            return redirect(reverse('leaders_apply'))
+
         return super().dispatch(request, *args, **kwargs)
 
 
+class AnyActivityLeaderApplyView(TemplateView):
+    template_name = 'leaders/apply_any_activity.html'
+
+    def get_context_data(self, **kwargs):
+        context = super().get_context_data(**kwargs)
+        context['activities_accepting_applications'] = [
+            activity_enum
+            for activity_enum in enums.Activity
+            if models.LeaderApplication.can_apply_for_activity(activity_enum)
+        ]
+        return context
+
+
 # model is a property on LeaderApplicationMixin, but a class attribute on MultipleObjectMixin
 class AllLeaderApplicationsView(ApplicationManager, ListView):  # type: ignore[misc]
     context_object_name = 'leader_applications'