[Bugfix] Properly escape NFO files (#168)

* Properly escaped NFO file contents

* Added an NFO backfill worker

* Added a try-catch to the backfill since I _really_ don't want failures to halt app boot

test/pinchflat/metadata/nfo_builder_test.exs

@@ -30,6 +30,21 @@ defmodule Pinchflat.Metadata.NfoBuilderTest do
       assert String.contains?(nfo, ~S(<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>))
       assert String.contains?(nfo, "<title>#{metadata["title"]}</title>")
     end
+
+    test "escapes invalid characters", %{filepath: filepath} do
+      metadata = %{
+        "title" => "hello' & <world>",
+        "uploader" => "uploader",
+        "id" => "id",
+        "description" => "description",
+        "upload_date" => "20210101"
+      }
+
+      result = NfoBuilder.build_and_store_for_media_item(filepath, metadata)
+      nfo = File.read!(result)
+
+      assert String.contains?(nfo, "hello&#39; &amp; &lt;world&gt;")
+    end
   end
 
   describe "build_and_store_for_source/2" do
@@ -46,5 +61,18 @@ defmodule Pinchflat.Metadata.NfoBuilderTest do
       assert String.contains?(nfo, ~S(<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>))
       assert String.contains?(nfo, "<title>#{metadata["title"]}</title>")
     end
+
+    test "escapes invalid characters", %{filepath: filepath} do
+      metadata = %{
+        "title" => "hello' & <world>",
+        "description" => "description",
+        "id" => "id"
+      }
+
+      result = NfoBuilder.build_and_store_for_source(filepath, metadata)
+      nfo = File.read!(result)
+
+      assert String.contains?(nfo, "hello&#39; &amp; &lt;world&gt;")
+    end
   end
 end

test/pinchflat/utils/xml_utils_test.exs

@@ -0,0 +1,16 @@
+defmodule Pinchflat.Utils.XmlUtilsTest do
+  use ExUnit.Case, async: true
+
+  alias Pinchflat.Utils.XmlUtils
+
+  describe "safe/1" do
+    test "escapes invalid characters" do
+      assert XmlUtils.safe("hello' & <world>") == "hello&#39; &amp; &lt;world&gt;"
+    end
+
+    test "converts input to string" do
+      assert XmlUtils.safe(42) == "42"
+      assert XmlUtils.safe(nil) == ""
+    end
+  end
+end