Add tests for previously uncovered modules

test/last_fm/import_test.exs

@@ -0,0 +1,50 @@
+defmodule LastFm.ImportTest do
+  use MusicLibrary.DataCase
+
+  alias MusicLibrary.ListeningStats
+
+  @recent_tracks_fixture Path.expand(
+                           "../support/fixtures/last_fm/user.getrecenttracks.json",
+                           __DIR__
+                         )
+
+  describe "batch/1" do
+    test "fetches recent tracks and persists them via ListeningStats" do
+      response = @recent_tracks_fixture |> File.read!() |> JSON.decode!()
+
+      Req.Test.stub(LastFm.API, fn conn ->
+        assert URI.decode_query(conn.query_string)["method"] == "user.getrecenttracks"
+
+        Req.Test.json(conn, response)
+      end)
+
+      assert {:ok, count} = LastFm.Import.batch([])
+      assert count > 0
+      assert ListeningStats.scrobble_count() == count
+    end
+
+    test "forwards limit and to_uts options to the Last.fm API" do
+      response = @recent_tracks_fixture |> File.read!() |> JSON.decode!()
+
+      Req.Test.stub(LastFm.API, fn conn ->
+        params = URI.decode_query(conn.query_string)
+        assert params["limit"] == "50"
+        assert params["to"] == "1730600000"
+
+        Req.Test.json(conn, response)
+      end)
+
+      assert {:ok, _count} = LastFm.Import.batch(limit: 50, to_uts: 1_730_600_000)
+    end
+
+    @tag :capture_log
+    test "returns {:error, reason} when the Last.fm API fails" do
+      Req.Test.stub(LastFm.API, fn conn ->
+        Req.Test.json(conn, %{"error" => 10, "message" => "Invalid API key"})
+      end)
+
+      assert {:error, :invalid_api_key} = LastFm.Import.batch([])
+      assert ListeningStats.scrobble_count() == 0
+    end
+  end
+end