refactor: add subscribed() queryset methods

radiofeed/episodes/models.py

@@ -27,6 +27,16 @@
 class EpisodeQuerySet(FastCountQuerySetMixin, SearchQuerySetMixin, FastUpdateQuerySet):
     """QuerySet for Episode model."""
 
+    def subscribed(self, user: User) -> models.QuerySet[Podcast]:
+        """Returns episodes belonging to episodes subscribed by user."""
+        return self.alias(
+            is_subscribed=models.Exists(
+                user.subscriptions.filter(
+                    podcast=models.OuterRef("podcast"),
+                )
+            )
+        ).filter(is_subscribed=True)
+
 
 class Episode(models.Model):
     """Individual podcast episode."""

radiofeed/episodes/tests/test_models.py

@@ -9,7 +9,7 @@
     EpisodeFactory,
 )
 from radiofeed.podcasts.models import Podcast
-from radiofeed.podcasts.tests.factories import PodcastFactory
+from radiofeed.podcasts.tests.factories import PodcastFactory, SubscriptionFactory
 
 
 class TestEpisodeManager:
@@ -23,6 +23,15 @@ def test_search_empty(self):
         EpisodeFactory(title="testing")
         assert Episode.objects.search("").count() == 0
 
+    @pytest.mark.django_db
+    def test_subscribed_true(self, user, episode):
+        SubscriptionFactory(subscriber=user, podcast=episode.podcast)
+        assert Episode.objects.subscribed(user).exists() is True
+
+    @pytest.mark.django_db
+    def test_subscribed_false(self, user, episode):
+        assert Episode.objects.subscribed(user).exists() is False
+
 
 class TestEpisodeModel:
     link = "https://example.com"

radiofeed/episodes/views.py

@@ -3,7 +3,6 @@
 from django.contrib import messages
 from django.contrib.auth.decorators import login_required
 from django.db import IntegrityError
-from django.db.models import Exists, OuterRef
 from django.http import (
     Http404,
     HttpRequest,
@@ -32,13 +31,8 @@ def index(request: HttpRequest) -> TemplateResponse:
     """List latest episodes from subscriptions."""
 
     episodes = (
-        Episode.objects.alias(
-            is_subscribed=Exists(
-                request.user.subscriptions.filter(podcast=OuterRef("podcast"))
-            )
-        )
+        Episode.objects.subscribed(request.user)
         .filter(
-            is_subscribed=True,
             pub_date__gt=timezone.now() - timedelta(days=14),
         )
         .select_related("podcast")

radiofeed/podcasts/models.py

@@ -103,6 +103,16 @@ def search(self, search_term: str) -> models.QuerySet[Podcast]:
             )
         return qs.annotate(exact_match=models.Value(0))
 
+    def subscribed(self, user: User) -> models.QuerySet[Podcast]:
+        """Returns podcasts subscribed by user."""
+        return self.alias(
+            is_subscribed=models.Exists(
+                user.subscriptions.filter(
+                    podcast=models.OuterRef("pk"),
+                )
+            )
+        ).filter(is_subscribed=True)
+
 
 class Podcast(models.Model):
     """Podcast channel or feed."""

radiofeed/podcasts/tests/test_models.py

@@ -6,6 +6,7 @@
     CategoryFactory,
     PodcastFactory,
     RecommendationFactory,
+    SubscriptionFactory,
 )
 
 
@@ -109,6 +110,15 @@ def test_compare_exact_and_partial_matches_in_search(self):
         assert second.title == "the testing"
         assert second.exact_match == 0
 
+    @pytest.mark.django_db
+    def test_subscribed_true(self, user):
+        SubscriptionFactory(subscriber=user)
+        assert Podcast.objects.subscribed(user).exists() is True
+
+    @pytest.mark.django_db
+    def test_subscribed_false(self, user, podcast):
+        assert Podcast.objects.subscribed(user).exists() is False
+
 
 class TestPodcastModel:
     def test_str(self):

radiofeed/podcasts/views.py

@@ -39,17 +39,7 @@ def index(request: HttpRequest) -> HttpResponseRedirect | TemplateResponse:
 @login_required
 def subscriptions(request: HttpRequest) -> TemplateResponse:
     """Render podcast index page."""
-    podcasts = (
-        _get_podcasts()
-        .alias(
-            is_subscribed=Exists(
-                request.user.subscriptions.filter(
-                    podcast=OuterRef("pk"),
-                )
-            )
-        )
-        .filter(is_subscribed=True)
-    )
+    podcasts = _get_podcasts().subscribed(request.user)
     podcasts = (
         podcasts.search(request.search.value).order_by(
             "-exact_match",
@@ -307,17 +297,7 @@ def unsubscribe(request: HttpRequest, podcast_id: int) -> TemplateResponse:
 @login_required
 def private_feeds(request: HttpRequest) -> TemplateResponse:
     """Lists user's private feeds."""
-    podcasts = (
-        _get_podcasts()
-        .alias(
-            is_subscribed=Exists(
-                request.user.subscriptions.filter(
-                    podcast=OuterRef("pk"),
-                )
-            )
-        )
-        .filter(private=True, is_subscribed=True)
-    )
+    podcasts = _get_podcasts().subscribed(request.user).filter(private=True)
 
     podcasts = (
         podcasts.search(request.search.value).order_by(