Explicit error handling when dealing with secrets

lib/music_library/scrobble_activity.ex

@@ -37,8 +37,7 @@ defmodule MusicLibrary.ScrobbleActivity do
     if release_duration == 0 do
       {:error, :no_duration}
     else
-      session_key = Secrets.get!("last_fm_session_key").value
-
+      with {:ok, session_key} <- fetch_session_key() do
         {scrobbles, _finished_at} =
           release_with_tracks
           |> MusicBrainz.Release.tracks()
@@ -47,6 +46,7 @@ defmodule MusicLibrary.ScrobbleActivity do
         LastFm.scrobble(scrobbles, session_key)
       end
     end
+  end
 
   def scrobble_medium(number, release_with_tracks, opts) when is_list(opts) do
     case Enum.sort(opts) do
@@ -83,8 +83,7 @@ defmodule MusicLibrary.ScrobbleActivity do
     if medium_duration == 0 do
       {:error, :no_duration}
     else
-      session_key = Secrets.get!("last_fm_session_key").value
-
+      with {:ok, session_key} <- fetch_session_key() do
         medium =
           release_with_tracks.media
           |> Enum.find(fn medium -> medium.number == number end)
@@ -96,6 +95,7 @@ defmodule MusicLibrary.ScrobbleActivity do
         LastFm.scrobble(scrobbles, session_key)
       end
     end
+  end
 
   def scrobble_tracks(selected_track_ids, release_with_tracks, opts) when is_list(opts) do
     case Enum.sort(opts) do
@@ -135,8 +135,7 @@ defmodule MusicLibrary.ScrobbleActivity do
     if tracks_duration == 0 do
       {:error, :no_duration}
     else
-      session_key = Secrets.get!("last_fm_session_key").value
-
+      with {:ok, session_key} <- fetch_session_key() do
         {scrobbles, _finished_at} =
           selected_tracks
           |> to_scrobbles(release_with_tracks, started_at)
@@ -144,6 +143,14 @@ defmodule MusicLibrary.ScrobbleActivity do
         LastFm.scrobble(scrobbles, session_key)
       end
     end
+  end
+
+  defp fetch_session_key do
+    case Secrets.get("last_fm_session_key") do
+      %{value: value} -> {:ok, value}
+      nil -> {:error, :no_session_key}
+    end
+  end
 
   defp to_scrobbles(tracks, release_with_tracks, started_at) do
     tracks