Relax assertions on colors

As dominant colors are not stable on different environments

test/music_library/colors/k_means_extractor_test.exs

@@ -1,19 +1,23 @@
 defmodule MusicLibrary.Colors.KMeansExtractorTest do
   use ExUnit.Case
 
+  import MusicLibrary.ColorHelpers, only: [color_hex?: 1]
+
   alias MusicLibrary.Colors.KMeansExtractor
 
   @image_data MusicLibrary.Fixtures.Records.marbles_cover_data()
 
   describe "extract_dominant_colors/1" do
     test "extracts 5 colors by default" do
-      assert {:ok, ["#101111", "#d3b696", "#836246", "#5d412d", "#3c2e22"]} ==
-               KMeansExtractor.extract_dominant_colors(@image_data)
+      assert {:ok, colors} = KMeansExtractor.extract_dominant_colors(@image_data)
+      assert length(colors) == 5
+      assert Enum.all?(colors, &color_hex?/1)
     end
 
     test "extracts custom number of colors" do
-      assert {:ok, ["#101111", "#d3b696", "#836246"]} ==
-               KMeansExtractor.extract_dominant_colors(@image_data, 3)
+      assert {:ok, colors} = KMeansExtractor.extract_dominant_colors(@image_data, 3)
+      assert length(colors) == 3
+      assert Enum.all?(colors, &color_hex?/1)
     end
   end
 end

test/music_library/records_test.exs

@@ -3,6 +3,7 @@ defmodule MusicLibrary.RecordsTest do
 
   import MusicBrainz.Fixtures.Release
   import MusicBrainz.Fixtures.ReleaseGroup
+  import MusicLibrary.ColorHelpers, only: [color_hex?: 1]
   import MusicLibrary.Fixtures.Records
 
   alias MusicLibrary.Assets
@@ -46,13 +47,8 @@ defmodule MusicLibrary.RecordsTest do
       assert record.cover_hash ==
                "599407DDF69907D4A60FE13CCAA824D25CF08DC124FD6AA3E8E7ECD98C885FFE"
 
-      assert record.dominant_colors == [
-               "#101111",
-               "#d3b696",
-               "#836246",
-               "#5d412d",
-               "#3c2e22"
-             ]
+      assert length(record.dominant_colors) == 5
+      assert Enum.all?(record.dominant_colors, &color_hex?/1)
     end
 
     test "it queues a task to retrieve artist info data" do

test/support/color_helpers.ex

@@ -0,0 +1,12 @@
+defmodule MusicLibrary.ColorHelpers do
+  @doc """
+  Returns true if the given string is a valid lowercase hex color code.
+
+      iex> MusicLibrary.ColorHelpers.color_hex?("#d3b696")
+      true
+
+      iex> MusicLibrary.ColorHelpers.color_hex?("not a color")
+      false
+  """
+  def color_hex?(value), do: String.match?(value, ~r/^#[0-9a-f]{6}$/)
+end