fix: issue #14 wrong sorting in category and tag archives

test/bds/generation/archive_ordering_test.exs

@@ -0,0 +1,39 @@
+defmodule BDS.Generation.ArchiveOrderingTest do
+  @moduledoc """
+  Category, tag and date archive listings must render newest first. The
+  generation post index is built by prepending, so this guards against the
+  regression where grouped archive lists came out in an unstable/oldest-first
+  order.
+  """
+  use ExUnit.Case, async: true
+
+  alias BDS.Generation.Data
+
+  defp post(slug, created_at, categories, tags) do
+    %{
+      id: slug,
+      slug: slug,
+      created_at: created_at,
+      published_at: created_at,
+      categories: categories,
+      tags: tags
+    }
+  end
+
+  test "categories, tags and dates are ordered newest first regardless of input order" do
+    older = post("older", 1_700_000_000_000, ["article"], ["elixir"])
+    newest = post("newest", 1_700_000_200_000, ["article"], ["elixir"])
+    middle = post("middle", 1_700_000_100_000, ["article"], ["elixir"])
+
+    # Deliberately unordered input.
+    index = Data.build_generation_post_index([older, newest, middle])
+
+    expected = ["newest", "middle", "older"]
+
+    assert Enum.map(index.posts_by_category["article"], & &1.slug) == expected
+    assert Enum.map(index.posts_by_tag["elixir"], & &1.slug) == expected
+
+    {year, _month, _day} = BDS.Generation.Paths.local_date_parts!(newest.created_at)
+    assert Enum.map(index.posts_by_year[year], & &1.slug) == expected
+  end
+end

test/bds/rendering_test.exs

@@ -246,7 +246,7 @@ defmodule BDS.RenderingTest do
                title: "Render Day Blocks",
                kind: :list,
                content:
-                 "range={{ min_date }}-{{ max_date }}|heading={{ show_archive_range_heading }}|blocks={% for block in day_blocks %}[{{ block.date_label }}:{{ block.posts.size }}:{{ block.show_date_marker }}]{% endfor %}|archive={{ archive_context.kind }}:{{ archive_context.year }}:{{ archive_context.month }}"
+                 "range={{ min_date }}-{{ max_date }}|heading={{ show_archive_range_heading }}|blocks={% for block in day_blocks %}[{{ block.date_label }}:{% for p in block.posts %}{{ p.slug }};{% endfor %}:{{ block.show_date_marker }}]{% endfor %}|archive={{ archive_context.kind }}:{{ archive_context.year }}:{{ archive_context.month }}"
              })
 
     assert {:ok, published_list_template} = BDS.Templates.publish_template(list_template.id)
@@ -289,6 +289,19 @@ defmodule BDS.RenderingTest do
         tags: [],
         categories: [],
         href: "/2024/04/01/second/"
+      },
+      %{
+        id: "second-b",
+        slug: "second-b",
+        title: "Second B",
+        excerpt: "two-b",
+        language: "en",
+        created_at: second_day + 3_600,
+        updated_at: second_day + 3_600,
+        published_at: second_day + 3_600,
+        tags: [],
+        categories: [],
+        href: "/2024/04/01/second-b/"
       }
     ]
 
@@ -311,9 +324,9 @@ defmodule BDS.RenderingTest do
              })
 
     assert rendered =~ "heading=true"
-    assert rendered =~ "blocks=[2024-03-31:1:true][2024-04-01:1:true]"
+    assert rendered =~ "blocks=[2024-04-01:second-b;second;:true][2024-03-31:first;:true]"
     assert rendered =~ "archive=date:2024:4"
-    assert rendered =~ "range=1711843200-1711929600"
+    assert rendered =~ "range=1711843200-1711933200"
   end
 
   test "render_post_page falls back to bundled starter template when the published default template file is missing",