Mox.defmock(MusicBrainz.APIBehaviourMock, for: MusicBrainz.APIBehaviour) Application.put_env(:music_library, :musicbrainz, MusicBrainz.APIBehaviourMock) music_brainz_config = Application.get_env(:music_library, MusicBrainz) new_music_brainz_config = Keyword.put(music_brainz_config, :api, MusicBrainz.APIBehaviourMock) Application.put_env(:music_library, MusicBrainz, new_music_brainz_config) Mox.defmock(LastFm.APIBehaviourMock, for: LastFm.APIBehaviour) last_fm_config = Application.get_env(:music_library, LastFm) new_last_fm_config = Keyword.put(last_fm_config, :api, LastFm.APIBehaviourMock) Application.put_env(:music_library, LastFm, new_last_fm_config) ExUnit.start() Ecto.Adapters.SQL.Sandbox.mode(MusicLibrary.Repo, :manual)