Add unit tests

src/tui/app/machine/fetch_state.rs

@@ -358,6 +358,81 @@ mod tests {
             .return_once(|_, _| Ok(()));
     }
 
+    #[test]
+    fn fetch_single_album() {
+        let mut mb_job_sender = MockIMbJobSender::new();
+
+        let artist_id = COLLECTION[1].meta.id.clone();
+        let artist_mbid: Mbid = "11111111-1111-1111-1111-111111111111".try_into().unwrap();
+
+        let album_meta = COLLECTION[1].albums[0].meta.clone();
+
+        search_release_group_expectation(
+            &mut mb_job_sender,
+            &artist_id,
+            &artist_mbid,
+            &[album_meta],
+        );
+
+        let music_hoard = music_hoard(COLLECTION.to_owned());
+        let inner = AppInner::new(music_hoard, mb_job_sender);
+
+        // Use second artist and have album selected to match the expectation.
+        let browse = AppMachine::browse_state(inner);
+        let browse = browse.increment_selection(Delta::Line).unwrap_browse();
+        let app = browse.increment_category();
+
+        let app = app.unwrap_browse().fetch_musicbrainz();
+        assert!(matches!(app, AppState::Fetch(_)));
+    }
+
+    #[test]
+    fn fetch_single_album_nothing_to_fetch() {
+        let music_hoard = music_hoard(COLLECTION.to_owned());
+        let inner = inner(music_hoard);
+
+        // Use second artist, have second album selected (has MBID) to match the expectation.
+        let browse = AppMachine::browse_state(inner);
+        let browse = browse.increment_selection(Delta::Line).unwrap_browse();
+        let browse = browse.increment_category().unwrap_browse();
+        let app = browse.increment_selection(Delta::Line);
+
+        let app = app.unwrap_browse().fetch_musicbrainz();
+        assert!(matches!(app, AppState::Browse(_)));
+    }
+
+    #[test]
+    fn fetch_single_album_no_artist_mbid() {
+        let music_hoard = music_hoard(COLLECTION.to_owned());
+        let inner = inner(music_hoard);
+
+        // Use third artist and have album selected to match the expectation.
+        let browse = AppMachine::browse_state(inner);
+        let browse = browse.increment_selection(Delta::Line).unwrap_browse();
+        let browse = browse.increment_selection(Delta::Line).unwrap_browse();
+        let app = browse.increment_category();
+
+        let app = app.unwrap_browse().fetch_musicbrainz();
+        assert!(matches!(app, AppState::Error(_)));
+    }
+
+    #[test]
+    fn fetch_single_album_no_album() {
+        let mut collection = COLLECTION.to_owned();
+        collection[1].albums.clear();
+
+        let music_hoard = music_hoard(collection);
+        let inner = inner(music_hoard);
+
+        // Use second artist and have album selected to match the expectation.
+        let browse = AppMachine::browse_state(inner);
+        let browse = browse.increment_selection(Delta::Line).unwrap_browse();
+        let app = browse.increment_category();
+
+        let app = app.unwrap_browse().fetch_musicbrainz();
+        assert!(matches!(app, AppState::Error(_)));
+    }
+
     #[test]
     fn fetch_albums() {
         let mut mb_job_sender = MockIMbJobSender::new();