From d39829c5ca0cbb189d2e9c5b76d6646042c3432c Mon Sep 17 00:00:00 2001
From: Claudio Ortolina <cloud8421@gmail.com>
Date: Wed, 8 Oct 2025 18:56:29 +0200
Subject: [PATCH] Add tests for MusicBrainz.ExternalLink

---
 .claude/settings.local.json              |   3 +-
 test/music_brainz/external_link_test.exs | 137 +++++++++++++++++++++++
 2 files changed, 139 insertions(+), 1 deletion(-)
 create mode 100644 test/music_brainz/external_link_test.exs

diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index 5129b763..b20cdc21 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -27,7 +27,8 @@
       "Bash(xargs sed:*)",
       "Bash(git show:*)",
       "Bash(cat:*)",
-      "Bash(mise tasks:*)"
+      "Bash(mise tasks:*)",
+      "Bash(mix run:*)"
     ]
   },
   "enableAllProjectMcpServers": false
diff --git a/test/music_brainz/external_link_test.exs b/test/music_brainz/external_link_test.exs
new file mode 100644
index 00000000..227254d4
--- /dev/null
+++ b/test/music_brainz/external_link_test.exs
@@ -0,0 +1,137 @@
+defmodule MusicBrainz.ExternalLinkTest do
+  use ExUnit.Case, async: true
+
+  alias MusicBrainz.ExternalLink
+  alias MusicBrainz.Fixtures.Artist
+
+  setup do
+    %{artist_data: Artist.get_artist()}
+  end
+
+  describe "external_links/2 with a single pattern" do
+    test "returns empty list when relations key is missing" do
+      assert ExternalLink.external_links(%{}, "spotify") == []
+    end
+
+    test "returns empty list when no URLs match the pattern", %{artist_data: artist_data} do
+      assert ExternalLink.external_links(artist_data, "nonexistent-pattern") == []
+    end
+
+    test "returns URLs matching the pattern", %{artist_data: artist_data} do
+      results = ExternalLink.external_links(artist_data, "spotify")
+
+      assert length(results) == 1
+      assert "https://open.spotify.com/artist/4X42BfuhWCAZ2swiVze9O0" in results
+    end
+
+    test "returns all URLs matching the pattern when multiple exist", %{artist_data: artist_data} do
+      results = ExternalLink.external_links(artist_data, "youtube")
+
+      assert length(results) == 2
+      assert "https://www.youtube.com/user/StevenWilsonHQ" in results
+      assert "https://music.youtube.com/channel/UCN_yfO7km9qK5n9JlLJRdrg" in results
+    end
+
+    test "returns all URLs when pattern is nil", %{artist_data: artist_data} do
+      results = ExternalLink.external_links(artist_data, nil)
+
+      # The fixture has 59 relations with URLs
+      assert length(results) == 59
+    end
+
+    test "pattern matching is case-sensitive", %{artist_data: artist_data} do
+      # Should not match because 'Spotify' != 'spotify'
+      assert ExternalLink.external_links(artist_data, "Spotify") == []
+    end
+
+    test "pattern matches substring of URL", %{artist_data: artist_data} do
+      results = ExternalLink.external_links(artist_data, "discogs")
+
+      assert length(results) == 1
+      assert "https://www.discogs.com/artist/227943" in results
+    end
+  end
+
+  describe "external_links/2 with pattern map" do
+    test "returns empty list when no patterns match", %{artist_data: artist_data} do
+      patterns = %{
+        fake1: "nonexistent1",
+        fake2: "nonexistent2"
+      }
+
+      assert ExternalLink.external_links(artist_data, patterns) == []
+    end
+
+    test "returns external link structs with names and URLs", %{artist_data: artist_data} do
+      patterns = %{
+        spotify: "spotify",
+        discogs: "discogs"
+      }
+
+      results = ExternalLink.external_links(artist_data, patterns)
+
+      assert length(results) == 2
+
+      spotify_link = Enum.find(results, fn link -> link.name == :spotify end)
+      assert spotify_link.url == "https://open.spotify.com/artist/4X42BfuhWCAZ2swiVze9O0"
+
+      discogs_link = Enum.find(results, fn link -> link.name == :discogs end)
+      assert discogs_link.url == "https://www.discogs.com/artist/227943"
+    end
+
+    test "returns only first matching URL when multiple URLs match same pattern", %{
+      artist_data: artist_data
+    } do
+      patterns = %{
+        youtube: "youtube"
+      }
+
+      results = ExternalLink.external_links(artist_data, patterns)
+
+      assert length(results) == 1
+      assert [youtube_link] = results
+      assert youtube_link.name == :youtube
+
+      # Should return the first matching URL
+      assert youtube_link.url in [
+               "https://www.youtube.com/user/StevenWilsonHQ",
+               "https://music.youtube.com/channel/UCN_yfO7km9qK5n9JlLJRdrg"
+             ]
+    end
+
+    test "handles mix of matching and non-matching patterns", %{artist_data: artist_data} do
+      patterns = %{
+        spotify: "spotify",
+        bandcamp: "bandcamp",
+        discogs: "discogs"
+      }
+
+      results = ExternalLink.external_links(artist_data, patterns)
+
+      # Only spotify and discogs should match
+      assert length(results) == 2
+
+      names = Enum.map(results, & &1.name)
+      assert :spotify in names
+      assert :discogs in names
+      refute :bandcamp in names
+    end
+
+    test "returns ExternalLink structs with correct structure", %{artist_data: artist_data} do
+      patterns = %{
+        lastfm: "last.fm"
+      }
+
+      results = ExternalLink.external_links(artist_data, patterns)
+
+      assert [link] = results
+      assert %ExternalLink{} = link
+      assert link.name == :lastfm
+      assert link.url == "https://www.last.fm/music/Steven+Wilson"
+    end
+
+    test "handles empty pattern map", %{artist_data: artist_data} do
+      assert ExternalLink.external_links(artist_data, %{}) == []
+    end
+  end
+end