16i-path-citations: point the clone URL at the new org, and gate dead links

README.md

@@ -206,7 +206,7 @@ Ultraviolet is currently best supported on **Linux**.
 ## 1. Clone the repository
 
 ```bash
-git clone https://github.com/HackTuah/Ultraviolet.git
+git clone https://github.com/ScriptKittyOS/Ultraviolet.git
 cd Ultraviolet
 ```
 

apps/hacktui_core/test/link_check_test.exs

@@ -0,0 +1,105 @@
+defmodule HacktuiCore.LinkCheckTest do
+  @moduledoc """
+  Every relative markdown link in `README.md` and `docs/` resolves to a file that exists.
+
+  A link check that has not been seen fail is a check that can only pass. Slice 16c is the
+  precedent: `Path.wildcard/1` does not match dot-prefixed names, so an unpinned dotfile was
+  invisible and the gate reported zero failures while the hole was open.
+
+  So `dead_links/2` takes its root and its source list as arguments, and the probes drive the
+  *same* function the real test calls, over fixtures. A control that computes its expected
+  value with the function under test asserts `f(x) == f(x)` and proves nothing.
+  """
+  use ExUnit.Case, async: true
+
+  import ExUnit.Callbacks, only: [on_exit: 1]
+
+  @root Path.expand("../../..", __DIR__)
+
+  @doc false
+  def dead_links(root, sources) do
+    for src <- sources,
+        target <- relative_links(File.read!(Path.join(root, src))),
+        not File.exists?(resolve(root, src, target)),
+        do: {src, target}
+  end
+
+  @doc false
+  def sources(root) do
+    ["README.md"]
+    |> Enum.concat(Path.wildcard(Path.join(root, "docs/**/*.md"), match_dot: true))
+    |> Enum.map(&Path.relative_to(&1, root))
+    |> Enum.filter(&File.regular?(Path.join(root, &1)))
+    |> Enum.sort()
+  end
+
+  # A markdown inline link whose target is relative: not a URL scheme, not a bare anchor.
+  defp relative_links(body) do
+    ~r/\[[^\]]*\]\(([^)\s]+)\)/
+    |> Regex.scan(body)
+    |> Enum.map(fn [_full, target] -> target end)
+    |> Enum.reject(&(&1 =~ ~r{^(https?://|mailto:|#)}))
+  end
+
+  # Anchors are stripped: `guide.md#section` is a link to `guide.md`.
+  defp resolve(root, src, target) do
+    file = target |> String.split("#") |> hd()
+    Path.expand(Path.join([root, Path.dirname(src), file]))
+  end
+
+  defp fixture(files) do
+    dir = Path.join(System.tmp_dir!(), "linkcheck-#{System.unique_integer([:positive])}")
+    File.mkdir_p!(dir)
+    on_exit(fn -> File.rm_rf!(dir) end)
+
+    Enum.each(files, fn {path, body} ->
+      full = Path.join(dir, path)
+      File.mkdir_p!(Path.dirname(full))
+      File.write!(full, body)
+    end)
+
+    dir
+  end
+
+  test "probe 1: a deliberately dead relative link is detected" do
+    dir = fixture(%{"README.md" => "see [the missing page](does_not_exist.md) for more\n"})
+
+    assert [{"README.md", "does_not_exist.md"}] == dead_links(dir, ["README.md"])
+  end
+
+  test "probe 2: a link into a nested directory resolves, and is not skipped" do
+    dir =
+      fixture(%{
+        "README.md" => "see [the deep page](docs/guides/deep.md)\n",
+        "docs/guides/deep.md" => "# deep\n"
+      })
+
+    assert [] == dead_links(dir, ["README.md"])
+
+    # and the checker is genuinely looking: break only the target and it goes red
+    File.rm!(Path.join(dir, "docs/guides/deep.md"))
+    assert [{"README.md", "docs/guides/deep.md"}] == dead_links(dir, ["README.md"])
+  end
+
+  test "probe 3: a link to a dot-named file resolves, and is not skipped" do
+    dir =
+      fixture(%{
+        "README.md" => "see [the workflow](.github/workflows/ci.yml)\n",
+        ".github/workflows/ci.yml" => "name: ci\n"
+      })
+
+    assert [] == dead_links(dir, ["README.md"])
+
+    # Path.wildcard/1 skips dot-prefixed names. A checker that enumerated candidate targets
+    # by wildcard would report this live link as dead; one that resolves the path does not.
+    File.rm!(Path.join(dir, ".github/workflows/ci.yml"))
+    assert [{"README.md", ".github/workflows/ci.yml"}] == dead_links(dir, ["README.md"])
+  end
+
+  test "probe 4: the tracked tree carries no dead relative links" do
+    sources = sources(@root)
+
+    assert sources != [], "no markdown sources found; the check would pass vacuously"
+    assert [] == dead_links(@root, sources)
+  end
+end