Speed up tests by caching cover data

Suggested and executed by Claude

test/music_library/records/cover_test.exs

@@ -7,7 +7,8 @@ defmodule MusicLibrary.Records.CoverTest do
 
   describe "resize/1" do
     test "it resizes to the desired size" do
-      cover_data = File.read!(marbles_cover_fixture())
+      # Use the cached cover data which is much faster than reading from disk
+      cover_data = marbles_cover_data()
       {:ok, resized_cover} = Cover.resize(cover_data)
       assert cover_data !== resized_cover
       assert Cover.correct_size?(resized_cover)

test/music_library/records_test.exs

@@ -226,7 +226,7 @@ defmodule MusicLibrary.RecordsTest do
       release_group_id = release_group_id(:marbles)
       release_group_releases = release_group_releases(:marbles)
 
-      cover_data = File.read!(marbles_cover_fixture())
+      cover_data = marbles_cover_data()
 
       Req.Test.stub(MusicBrainz.API, fn conn ->
         case conn.path_info do
@@ -282,7 +282,7 @@ defmodule MusicLibrary.RecordsTest do
       release_group_id = release_group_id(:marbles)
       release_group_releases = release_group_releases(:marbles)
 
-      cover_data = File.read!(marbles_cover_fixture())
+      cover_data = marbles_cover_data()
 
       Req.Test.stub(MusicBrainz.API, fn conn ->
         case conn.path_info do
@@ -332,9 +332,9 @@ defmodule MusicLibrary.RecordsTest do
 
   describe "refresh cover/1" do
     test "it fetches and stores the updated cover" do
-      record = record(cover_data: File.read!(marbles_cover_fixture()))
+      record = record(cover_data: marbles_cover_data())
 
-      raven_cover_data = File.read!(raven_cover_fixture())
+      raven_cover_data = raven_cover_data()
 
       Req.Test.stub(MusicBrainz.API, fn conn ->
         Plug.Conn.send_resp(conn, 200, raven_cover_data)

test/music_library_web/controllers/cover_controller_test.exs

@@ -61,7 +61,7 @@ defmodule MusicLibraryWeb.CoverControllerTest do
     test "accepts a size attribute for resizing", %{conn: conn, record: record} do
       conn = get(conn, ~p"/covers/#{record.id}?size=480")
 
-      thumb = File.read!(marbles_thumb_fixture())
+      thumb = marbles_thumb_data()
       hash = Cover.hash(thumb)
 
       assert conn.status == 200

test/music_library_web/live/collection_live/index_test.exs

@@ -217,7 +217,7 @@ defmodule MusicLibraryWeb.CollectionLive.IndexTest do
     end
 
     test "can change the record cover", %{conn: conn} do
-      record = record(cover_data: File.read!(marbles_cover_fixture()))
+      record = record(cover_data: marbles_cover_data())
       cover_url = ~p"/covers/#{record.id}?vsn=#{record.cover_hash}"
 
       session =
@@ -258,7 +258,7 @@ defmodule MusicLibraryWeb.CollectionLive.IndexTest do
       release_group = release_group(:marbles)
       release_group_releases = release_group_releases(:marbles)
 
-      cover_data = File.read!(marbles_cover_fixture())
+      cover_data = marbles_cover_data()
 
       Req.Test.stub(MusicBrainz.API, fn conn ->
         case conn.path_info do
@@ -367,7 +367,7 @@ defmodule MusicLibraryWeb.CollectionLive.IndexTest do
     release_group_id = release_group["id"]
     release_group_releases = release_group_releases(:marbles)
 
-    cover_data = File.read!(marbles_cover_fixture())
+    cover_data = marbles_cover_data()
 
     Req.Test.stub(MusicBrainz.API, fn conn ->
       case conn.path_info do

test/music_library_web/live/stats_live/index_test.exs

@@ -211,7 +211,7 @@ defmodule MusicLibraryWeb.StatsLive.IndexTest do
       release_group_id = release_group_id(:mystery_of_time)
       release_group_releases = release_group_releases(:mystery_of_time)
 
-      cover_data = File.read!(marbles_cover_fixture())
+      cover_data = marbles_cover_data()
 
       Req.Test.stub(MusicBrainz.API, fn conn ->
         case conn.path_info do

test/support/fixtures/music_library/records.ex

@@ -46,10 +46,19 @@ defmodule MusicLibrary.Fixtures.Records do
   @marbles_thumb_data_path "#{__DIR__}/marillion-marbles-thumb.jpg"
   @raven_cover_data_path "#{__DIR__}/steven-wilson-raven.jpg"
 
+  # Cache image data at module load time to avoid repeated file I/O
+  @marbles_cover_data File.read!(@marbles_cover_data_path)
+  @marbles_thumb_data File.read!(@marbles_thumb_data_path)
+  @raven_cover_data File.read!(@raven_cover_data_path)
+
   def marbles_cover_fixture, do: @marbles_cover_data_path
   def marbles_thumb_fixture, do: @marbles_thumb_data_path
   def raven_cover_fixture, do: @raven_cover_data_path
 
+  def marbles_cover_data, do: @marbles_cover_data
+  def marbles_thumb_data, do: @marbles_thumb_data
+  def raven_cover_data, do: @raven_cover_data
+
   def record(attrs \\ %{}) do
     record_musicbrainz_id = Ecto.UUID.generate()
     artist_name = Enum.random(@artists)
@@ -60,7 +69,7 @@ defmodule MusicLibrary.Fixtures.Records do
       |> Enum.into(%{
         genres: Enum.take_random(@genres, :rand.uniform(3)),
         cover_url: "https://coverartarchive.org/release-group/#{record_musicbrainz_id}/front",
-        cover_data: File.read!(@marbles_cover_data_path),
+        cover_data: @marbles_cover_data,
         musicbrainz_id: record_musicbrainz_id,
         musicbrainz_data: ReleaseGroup.release_group(:marbles),
         title: Enum.random(@titles),