feat: add get subtitle helper

lib/media_server_web/helpers.ex

@@ -63,4 +63,10 @@ defmodule MediaServerWeb.Helpers do
   def reduce_size_for_poster_url(url) do
     String.replace(url, "original", "w342")
   end
+
+  def get_subtitle(path) do
+    File.ls!(path)
+    |> Enum.filter(fn item -> String.contains?(item, ".srt") end)
+    |> List.first()
+  end
 end

test/media_server_web/helpers_test.exs

@@ -6,4 +6,24 @@ defmodule MediaServerWeb.HelpersTest do
              "https://some.domain.url/t/p/original/somePosterIdentifier.jpg"
            ) === "https://some.domain.url/t/p/w342/somePosterIdentifier.jpg"
   end
+
+  @path "fixtures/movies/Caminandes Llama Drama (2013)"
+  @expected [".DS_Store", "Caminandes.Llama.Drama.1080p.mp4", "Caminandes.Llama.Drama.1080p.srt"]
+  @filtered "Caminandes.Llama.Drama.1080p.srt"
+
+  test "it should have subtitle" do
+    assert File.ls!(@path) == @expected
+
+    assert MediaServerWeb.Helpers.get_subtitle(@path) == @filtered
+  end
+
+  @path_without "fixtures/movies/Caminandes Gran Dillama (2013)"
+  @expected_without [".DS_Store", "Caminandes.Gran.Dillama.1080p.mp4"]
+  @filtered_without nil
+
+  test "it should not have subtitle" do
+    assert File.ls!(@path_without) == @expected_without
+
+    assert MediaServerWeb.Helpers.get_subtitle(@path_without) == @filtered_without
+  end
 end