Improve tests: better assertions, meaningful tests

Track resulting principles in project conventions

test/music_library/artists/batch_test.exs

@@ -8,31 +8,43 @@ defmodule MusicLibrary.Artists.BatchTest do
   setup do
     record = record()
     artist = hd(record.artists)
-    _artist_info = artist_info(artist.musicbrainz_id)
-    :ok
+    artist_info = artist_info(artist.musicbrainz_id)
+    %{artist_info: artist_info}
   end
 
   describe "refresh_musicbrainz_data/0" do
-    test "enqueues refresh jobs for all artist infos" do
+    test "enqueues refresh jobs for all artist infos", %{artist_info: artist_info} do
       assert {:ok, []} = Batch.refresh_musicbrainz_data()
+
+      assert_enqueued worker: MusicLibrary.Worker.ArtistRefreshMusicBrainzData,
+                      args: %{id: artist_info.id}
     end
   end
 
   describe "refresh_discogs_data/0" do
-    test "enqueues refresh jobs for all artist infos" do
+    test "enqueues refresh jobs for all artist infos", %{artist_info: artist_info} do
       assert {:ok, []} = Batch.refresh_discogs_data()
+
+      assert_enqueued worker: MusicLibrary.Worker.ArtistRefreshDiscogsData,
+                      args: %{id: artist_info.id}
     end
   end
 
   describe "refresh_wikipedia_data/0" do
-    test "enqueues refresh jobs for all artist infos" do
+    test "enqueues refresh jobs for all artist infos", %{artist_info: artist_info} do
       assert {:ok, []} = Batch.refresh_wikipedia_data()
+
+      assert_enqueued worker: MusicLibrary.Worker.ArtistRefreshWikipediaData,
+                      args: %{id: artist_info.id}
     end
   end
 
   describe "refresh_lastfm_data/0" do
-    test "enqueues refresh jobs for all artist infos" do
+    test "enqueues refresh jobs for all artist infos", %{artist_info: artist_info} do
       assert {:ok, []} = Batch.refresh_lastfm_data()
+
+      assert_enqueued worker: MusicLibrary.Worker.FetchArtistLastFmData,
+                      args: %{id: artist_info.id}
     end
   end
 end