yak(behavior-tests-blogex-public-api-and-router-plumbing-q1fb): behavior tests: blogex public API and router plumbing

blogex/lib/blogex/link_validator.ex

@@ -232,10 +232,10 @@ defmodule Blogex.LinkValidator do
   @doc false
   @spec slug_end(String.t()) :: integer()
   defp slug_end(str) do
-    case String.split(str, ["?", "#"], parts: 2) do
-      [slug | _] -> String.length(slug)
-      _ -> String.length(str)
-    end
+    # `String.split/3` always returns a non-empty list whose head is a binary,
+    # so there is no empty/other case to handle here.
+    [slug | _] = String.split(str, ["?", "#"], parts: 2)
+    String.length(slug)
   end
 
   @doc false

blogex/mix.exs

@@ -56,18 +56,22 @@ defmodule Blogex.MixProject do
   # in blogex/). Rule: the threshold is a FLOOR. Raise it as behavior-test yaks
   # land; never lower it. A drop means the change (or an exclusion) is wrong.
   #
-  # Measured 2026-10-26, with the test scaffolding below excluded: 74.53% — the
+  # Measured 2026-10-28, with the test scaffolding below excluded: 78.59% — the
   # same via `mix test --cover` and via `mix test --cover --export-coverage
   # default` + `mix test.coverage`. Floor is the integer below that.
   #
-  # Excluded: the test scaffolding (Blogex.Test.*) only. Fixtures measure the
-  # tests, not the library. Everything in lib/blogex counts, and today's gaps
-  # are real: Blogex (the delegating facade), Blogex.Components and
-  # Blogex.Layout are at 0% because the router tests only exercise the JSON
-  # responses — moving this floor up is the behavior-test work.
+  # Excluded: the test scaffolding in `ignore_modules` below. The two registry
+  # blog doubles (Blogex.Test.AlphaBlog/BetaBlog) are deliberately not listed
+  # there: they are fully exercised, and excluding them measures 78.06% — the
+  # 78 floor holds either way.
+  #
+  # Everything in lib/blogex counts, and today's gaps are real:
+  # Blogex.Components and Blogex.Layout are at 0% because the router tests only
+  # exercise the JSON responses — covering the rendered HTML is its own yak.
+  # Blogex.Router (72.06%) still has its HTML arms and `match _` uncovered.
   defp test_coverage do
     [
-      summary: [threshold: 74],
+      summary: [threshold: 78],
       ignore_modules: [
         Blogex.Test.FakeBlog,
         Blogex.Test.PostBuilder,

blogex/priv/blog/test/2026/01-03-draft-post.md

@@ -0,0 +1,8 @@
+%{
+  title: "Draft Post (test fixture)",
+  author: "Test Author",
+  description: "A draft used by the show_drafts? tests",
+  published: false
+}
+---
+This post is a draft and is hidden unless :show_drafts is on.

blogex/test/blogex/blog_integration_test.exs

@@ -127,4 +127,41 @@ defmodule Blogex.BlogIntegrationTest do
       File.rm!(tmp_file)
     end
   end
+
+  describe "show_drafts?/0" do
+    # The only path through `Blogex.show_drafts?/0` (blogex.ex): `use Blogex.Blog`
+    # compiles a real module over a real draft fixture, so the flag is read by
+    # the generated `all_posts/0` rather than asserted in isolation.
+    #
+    # One test, one compile: compiling the same module name twice would print a
+    # "redefining module" warning, and warnings are fatal everywhere in this repo.
+    test "drafts are hidden by default and visible when :show_drafts is on" do
+      tmp_file = Path.join(System.tmp_dir!(), "test_blog_show_drafts.ex")
+
+      File.write!(tmp_file, """
+      defmodule TestBlogShowDrafts do
+        use Blogex.Blog,
+          blog_id: :test,
+          app: :blogex,
+          from: "priv/blog/test/2026/01-03-draft-post.md",
+          title: "Test Blog",
+          base_path: "/blog/test"
+      end
+      """)
+
+      [{TestBlogShowDrafts, _bytecode}] = Code.compile_file(tmp_file, __ENV__.file)
+
+      on_exit(fn ->
+        File.rm!(tmp_file)
+        Application.delete_env(:blogex, :show_drafts)
+      end)
+
+      assert apply(TestBlogShowDrafts, :all_posts, []) == []
+
+      Application.put_env(:blogex, :show_drafts, true)
+
+      assert [post] = apply(TestBlogShowDrafts, :all_posts, [])
+      assert post.title == "Draft Post (test fixture)"
+    end
+  end
 end

blogex/test/blogex/link_validator_test.exs

@@ -324,4 +324,18 @@ defmodule Blogex.LinkValidatorTest do
              }
     end
   end
+
+  describe "parse_blog_link/1" do
+    # `slug_end/1` decides where the slug stops so `?query` / `#fragment` are
+    # not validated as part of it. Pinned directly on `parse_blog_link/1`
+    # (both are `@doc false`) because `validate_link/1` only reaches them via
+    # "valid slug" cases, and a wrong cut would still validate by luck.
+    test "strips query strings and fragments from the slug" do
+      assert LinkValidator.parse_blog_link("/blog/engineering/hello-world?utm=1") ==
+               {"engineering", "hello-world"}
+
+      assert LinkValidator.parse_blog_link("/blog/engineering/hello-world#top") ==
+               {"engineering", "hello-world"}
+    end
+  end
 end

blogex/test/blogex/registry_test.exs

@@ -2,41 +2,7 @@ defmodule Blogex.RegistryTest do
   use ExUnit.Case
 
   alias Blogex.Registry
-
-  defmodule AlphaBlog do
-    def blog_id, do: :alpha
-
-    def all_posts,
-      do: [Blogex.Test.PostBuilder.build(id: "a1", date: ~D[2026-03-01], blog: :alpha)]
-
-    def all_tags, do: ["elixir"]
-
-    def unfiltered_posts,
-      do: [
-        Blogex.Test.PostBuilder.build(id: "a1", date: ~D[2026-03-01], blog: :alpha),
-        Blogex.Test.PostBuilder.build(
-          id: "a-draft",
-          date: ~D[2026-03-05],
-          blog: :alpha,
-          published: false
-        )
-      ]
-  end
-
-  defmodule BetaBlog do
-    def blog_id, do: :beta
-
-    def all_posts,
-      do: [Blogex.Test.PostBuilder.build(id: "b1", date: ~D[2026-03-15], blog: :beta)]
-
-    def all_tags, do: ["devops"]
-
-    def unfiltered_posts,
-      do: [
-        Blogex.Test.PostBuilder.build(id: "b1", date: ~D[2026-03-15], blog: :beta),
-        Blogex.Test.PostBuilder.build(id: "b-future", date: ~D[2099-01-01], blog: :beta)
-      ]
-  end
+  alias Blogex.Test.{AlphaBlog, BetaBlog}
 
   setup do
     Application.put_env(:blogex, :blogs, [AlphaBlog, BetaBlog])

blogex/test/blogex/router_test.exs

@@ -153,6 +153,26 @@ defmodule Blogex.RouterTest do
     end
   end
 
+  describe "Helpers.base_url/1" do
+    # `port_suffix/2` has one clause per (scheme, default port) pair plus the
+    # catch-all, and the feeds embed this URL. All four shapes are pinned so a
+    # clause cannot be dropped or reordered without a failure.
+    test "omits the port for the default scheme ports" do
+      assert base_url(:http, 80) == "http://www.example.com"
+      assert base_url(:https, 443) == "https://www.example.com"
+    end
+
+    test "keeps a non-default port" do
+      assert base_url(:http, 4000) == "http://www.example.com:4000"
+      assert base_url(:https, 8443) == "https://www.example.com:8443"
+    end
+
+    defp base_url(scheme, port) do
+      %{Plug.Test.conn(:get, "/") | scheme: scheme, port: port}
+      |> Blogex.Router.Helpers.base_url()
+    end
+  end
+
   defp get_content_type(conn) do
     conn
     |> Plug.Conn.get_resp_header("content-type")

blogex/test/blogex_test.exs

@@ -0,0 +1,67 @@
+defmodule BlogexTest do
+  @moduledoc """
+  Behaviour tests for the `Blogex` facade.
+
+  The facade is a thin delegating layer over `Blogex.Registry`, but callers
+  (Phoenix controllers, LiveViews) only ever see the answers, so these tests
+  assert the answers: the exact module lists, post orderings and tag sets the
+  fixtures imply. Asserting `Blogex.x() == Blogex.Registry.x()` would pin the
+  delegation instead of the behaviour and would keep passing if both sides
+  drifted together.
+
+  Non-async: the registry is configured through the process-global `:blogex`
+  application env.
+  """
+  use ExUnit.Case
+
+  alias Blogex.Test.{AlphaBlog, BetaBlog}
+
+  setup do
+    Application.put_env(:blogex, :blogs, [AlphaBlog, BetaBlog])
+    on_exit(fn -> Application.delete_env(:blogex, :blogs) end)
+  end
+
+  describe "blogs/0" do
+    test "returns the configured blog modules" do
+      assert Blogex.blogs() == [AlphaBlog, BetaBlog]
+    end
+  end
+
+  describe "get_blog!/1 and get_blog/1" do
+    test "return the module registered for a blog_id" do
+      assert Blogex.get_blog!(:alpha) == AlphaBlog
+      assert Blogex.get_blog(:beta) == BetaBlog
+    end
+
+    test "an unknown blog_id returns nil and raises" do
+      assert Blogex.get_blog(:nope) == nil
+
+      assert_raise Blogex.NotFoundError, fn -> Blogex.get_blog!(:nope) end
+    end
+  end
+
+  describe "all_posts/0" do
+    # Newest first across both blogs: beta's 2026-03-15 post, then alpha's
+    # 2026-03-01. Drafts (a-draft) and future-dated posts (b-future) are not
+    # visible to readers, so neither appears.
+    test "merges published posts from every blog, newest first" do
+      assert ids(Blogex.all_posts()) == ["b1", "a1"]
+    end
+  end
+
+  describe "all_posts_unfiltered/0" do
+    # Everything, newest first: the 2099 scheduled post, then b1, the alpha
+    # draft, and alpha's oldest.
+    test "includes drafts and future-dated posts, newest first" do
+      assert ids(Blogex.all_posts_unfiltered()) == ["b-future", "b1", "a-draft", "a1"]
+    end
+  end
+
+  describe "all_tags/0" do
+    test "returns the unique tags across blogs, sorted" do
+      assert Blogex.all_tags() == ["devops", "elixir"]
+    end
+  end
+
+  defp ids(posts), do: Enum.map(posts, & &1.id)
+end

blogex/test/support/blogex_test_blogs.ex

@@ -0,0 +1,49 @@
+defmodule Blogex.Test.AlphaBlog do
+  @moduledoc """
+  A minimal blog module for cross-blog tests.
+
+  Implements the interface `Blogex.Registry` queries (and nothing else), so a
+  test can configure `:blogex, :blogs` with real modules without compiling a
+  `use Blogex.Blog` module or touching the filesystem.
+
+  `all_posts/0`/`unfiltered_posts/0` are hard-coded — the dates are literals so
+  tests can assert exact orderings rather than re-deriving them.
+  """
+
+  def blog_id, do: :alpha
+
+  def all_posts,
+    do: [Blogex.Test.PostBuilder.build(id: "a1", date: ~D[2026-03-01], blog: :alpha)]
+
+  def all_tags, do: ["elixir"]
+
+  def unfiltered_posts,
+    do: [
+      Blogex.Test.PostBuilder.build(id: "a1", date: ~D[2026-03-01], blog: :alpha),
+      Blogex.Test.PostBuilder.build(
+        id: "a-draft",
+        date: ~D[2026-03-05],
+        blog: :alpha,
+        published: false
+      )
+    ]
+end
+
+defmodule Blogex.Test.BetaBlog do
+  @moduledoc """
+  The second blog module for cross-blog tests; see `Blogex.Test.AlphaBlog`.
+  """
+
+  def blog_id, do: :beta
+
+  def all_posts,
+    do: [Blogex.Test.PostBuilder.build(id: "b1", date: ~D[2026-03-15], blog: :beta)]
+
+  def all_tags, do: ["devops"]
+
+  def unfiltered_posts,
+    do: [
+      Blogex.Test.PostBuilder.build(id: "b1", date: ~D[2026-03-15], blog: :beta),
+      Blogex.Test.PostBuilder.build(id: "b-future", date: ~D[2099-01-01], blog: :beta)
+    ]
+end