Add category taxonomy and navigation integration

Implements Issue #35 with category snippets, article category routing, category-aware templates, and category RSS feeds with tests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

apps/blog/tests/test_feeds_more.py

@@ -1,6 +1,8 @@
 import pytest
 
 from apps.blog.feeds import AllArticlesFeed
+from apps.blog.models import ArticleIndexPage, ArticlePage, Category
+from apps.blog.tests.factories import AuthorFactory
 
 
 @pytest.mark.django_db
@@ -16,3 +18,32 @@ def test_all_feed_methods(article_page):
 def test_tag_feed_not_found(client):
     resp = client.get("/feed/tag/does-not-exist/")
     assert resp.status_code == 404
+
+
+@pytest.mark.django_db
+def test_category_feed_endpoint(client, home_page):
+    index = ArticleIndexPage(title="Articles", slug="articles")
+    home_page.add_child(instance=index)
+    category = Category.objects.create(name="Reviews", slug="reviews")
+    author = AuthorFactory()
+    article = ArticlePage(
+        title="Feed Review",
+        slug="feed-review",
+        author=author,
+        summary="summary",
+        body=[("rich_text", "<p>Body</p>")],
+        category=category,
+    )
+    index.add_child(instance=article)
+    article.save_revision().publish()
+
+    resp = client.get("/feed/category/reviews/")
+    assert resp.status_code == 200
+    assert resp["Content-Type"].startswith("application/rss+xml")
+    assert "Feed Review" in resp.content.decode()
+
+
+@pytest.mark.django_db
+def test_category_feed_not_found(client):
+    resp = client.get("/feed/category/does-not-exist/")
+    assert resp.status_code == 404

apps/blog/tests/test_models.py

@@ -2,7 +2,7 @@ import pytest
 from django.db import IntegrityError
 from taggit.models import Tag
 
-from apps.blog.models import ArticleIndexPage, ArticlePage, HomePage, TagMetadata
+from apps.blog.models import ArticleIndexPage, ArticlePage, Category, HomePage, TagMetadata
 from apps.blog.tests.factories import AuthorFactory
 
 
@@ -40,3 +40,29 @@ def test_tag_metadata_css_and_uniqueness():
     assert meta.get_css_classes()["bg"] == "bg-brand-cyan/10"
     with pytest.raises(IntegrityError):
         TagMetadata.objects.create(tag=tag, colour="pink")
+
+
+@pytest.mark.django_db
+def test_article_default_category_is_assigned(home_page):
+    index = ArticleIndexPage(title="Articles", slug="articles")
+    home_page.add_child(instance=index)
+    author = AuthorFactory()
+    article = ArticlePage(
+        title="Categorised",
+        slug="categorised",
+        author=author,
+        summary="s",
+        body=[("rich_text", "<p>body</p>")],
+    )
+    index.add_child(instance=article)
+    article.save()
+    assert article.category.slug == "general"
+
+
+@pytest.mark.django_db
+def test_category_ordering():
+    Category.objects.get_or_create(name="General", slug="general")
+    Category.objects.create(name="Z", slug="z", sort_order=2)
+    Category.objects.create(name="A", slug="a", sort_order=1)
+    names = list(Category.objects.values_list("name", flat=True))
+    assert names == ["General", "A", "Z"]

apps/blog/tests/test_views.py

@@ -1,7 +1,7 @@
 import pytest
 from taggit.models import Tag
 
-from apps.blog.models import ArticleIndexPage, ArticlePage
+from apps.blog.models import ArticleIndexPage, ArticlePage, Category
 from apps.blog.tests.factories import AuthorFactory
 from apps.comments.models import Comment
 
@@ -161,3 +161,75 @@ def test_article_index_renders_tag_filter_controls(client, home_page):
     html = resp.content.decode()
     assert resp.status_code == 200
     assert "/articles/?tag=tag-one" in html
+
+
+@pytest.mark.django_db
+def test_article_index_category_route_filters_articles(client, home_page):
+    index = ArticleIndexPage(title="Articles", slug="articles")
+    home_page.add_child(instance=index)
+    author = AuthorFactory()
+    reviews = Category.objects.create(name="Reviews", slug="reviews")
+    tutorials = Category.objects.create(name="Tutorials", slug="tutorials")
+    review_article = ArticlePage(
+        title="Review A",
+        slug="review-a",
+        author=author,
+        summary="summary",
+        body=[("rich_text", "<p>body</p>")],
+        category=reviews,
+    )
+    tutorial_article = ArticlePage(
+        title="Tutorial A",
+        slug="tutorial-a",
+        author=author,
+        summary="summary",
+        body=[("rich_text", "<p>body</p>")],
+        category=tutorials,
+    )
+    index.add_child(instance=review_article)
+    review_article.save_revision().publish()
+    index.add_child(instance=tutorial_article)
+    tutorial_article.save_revision().publish()
+
+    resp = client.get("/articles/category/reviews/")
+    html = resp.content.decode()
+    assert resp.status_code == 200
+    assert "Review A" in html
+    assert "Tutorial A" not in html
+
+
+@pytest.mark.django_db
+def test_article_index_category_route_supports_tag_filter(client, home_page):
+    index = ArticleIndexPage(title="Articles", slug="articles")
+    home_page.add_child(instance=index)
+    author = AuthorFactory()
+    reviews = Category.objects.create(name="Reviews", slug="reviews")
+    keep = ArticlePage(
+        title="Keep Me",
+        slug="keep-me",
+        author=author,
+        summary="summary",
+        body=[("rich_text", "<p>body</p>")],
+        category=reviews,
+    )
+    drop = ArticlePage(
+        title="Drop Me",
+        slug="drop-me",
+        author=author,
+        summary="summary",
+        body=[("rich_text", "<p>body</p>")],
+        category=reviews,
+    )
+    index.add_child(instance=keep)
+    keep.save_revision().publish()
+    index.add_child(instance=drop)
+    drop.save_revision().publish()
+    target_tag = Tag.objects.create(name="Python", slug="python")
+    keep.tags.add(target_tag)
+    keep.save_revision().publish()
+
+    resp = client.get("/articles/category/reviews/?tag=python")
+    html = resp.content.decode()
+    assert resp.status_code == 200
+    assert "Keep Me" in html
+    assert "Drop Me" not in html