diff --git a/src/core/collection/artist.rs b/src/core/collection/artist.rs
index 91c2391..4f71420 100644
--- a/src/core/collection/artist.rs
+++ b/src/core/collection/artist.rs
@@ -301,7 +301,7 @@ impl Display for ArtistId {
 
 #[cfg(test)]
 mod tests {
-    use crate::core::testmod::FULL_COLLECTION;
+    use crate::{collection::album::AlbumId, core::testmod::FULL_COLLECTION};
 
     use super::*;
 
@@ -571,4 +571,59 @@ mod tests {
         let merged = left.clone().merge(right);
         assert_eq!(expected, merged);
     }
+
+    #[test]
+    #[should_panic(expected = "multiple secondaries unsupported")]
+    fn merge_two_db_albums_to_one_lib_album() {
+        let mut left = Artist::new(ArtistId::new("Artist"));
+        let mut right = left.clone();
+
+        let album = Album::new(AlbumId::new("Album"));
+
+        left.albums.push(album.clone());
+        left.albums[0].meta.id.lib_id = AlbumLibId::Value(1);
+
+        right.albums.push(album.clone());
+        right.albums.push(album.clone());
+
+        left.merge(right);
+    }
+
+    #[test]
+    #[should_panic(expected = "multiple primaries unsupported")]
+    fn merge_one_db_album_to_two_lib_albums() {
+        let mut left = Artist::new(ArtistId::new("Artist"));
+        let mut right = left.clone();
+
+        let album = Album::new(AlbumId::new("Album"));
+
+        left.albums.push(album.clone());
+        left.albums.push(album.clone());
+        left.albums[0].meta.id.lib_id = AlbumLibId::Value(1);
+        left.albums[1].meta.id.lib_id = AlbumLibId::Value(2);
+
+        right.albums.push(album.clone());
+
+        left.merge(right);
+    }
+
+    #[test]
+    fn merge_normalized_album_titles() {
+        let mut left = Artist::new(ArtistId::new("Artist"));
+        let mut right = left.clone();
+
+        left.albums.push(Album::new(AlbumId::new("Album‐Title ‘Title’")));
+        left.albums[0].meta.id.lib_id = AlbumLibId::Value(1);
+
+        right.albums.push(Album::new(AlbumId::new("alBum—tiTle 'title’")));
+        right.albums.push(Album::new(AlbumId::new("Album‐Title “Title”")));
+
+        // The first album will be merged, the second will be added.
+        let mut expected = left.clone();
+        expected.albums.push(right.albums.last().unwrap().clone());
+        expected.albums.sort_unstable();
+
+        let merged = left.merge(right);
+        assert_eq!(expected, merged);
+    }
 }
diff --git a/src/core/collection/merge.rs b/src/core/collection/merge.rs
index b414973..796045a 100644
--- a/src/core/collection/merge.rs
+++ b/src/core/collection/merge.rs
@@ -115,8 +115,8 @@ impl MergeCollections {
                 Some(mut primary_items) => {
                     // We do not support merging multiple items with same name yet. Support will be
                     // added once encountered in the wild.
-                    assert_eq!(primary_items.len(), 1);
-                    assert_eq!(secondary_items.len(), 1);
+                    assert_eq!(primary_items.len(), 1, "multiple primaries unsupported");
+                    assert_eq!(secondary_items.len(), 1, "multiple secondaries unsupported");
                     let mut primary_item = primary_items.pop().unwrap();
                     primary_item.merge_in_place(secondary_items.pop().unwrap());
                     merged.push(primary_item);
diff --git a/src/core/musichoard/base.rs b/src/core/musichoard/base.rs
index ddd0827..3d0c4c5 100644
--- a/src/core/musichoard/base.rs
+++ b/src/core/musichoard/base.rs
@@ -223,4 +223,72 @@ mod tests {
         mh.collection = mh.merge_collections();
         assert_eq!(expected, mh.collection);
     }
+
+
+    #[test]
+    #[should_panic(expected = "multiple secondaries unsupported")]
+    fn merge_two_db_artists_to_one_lib_artist() {
+        let mut left = Collection::new();
+        let mut right = Collection::new();
+
+        let artist = Artist::new(ArtistId::new("Artist"));
+
+        left.push(artist.clone());
+        right.push(artist.clone());
+        right.push(artist.clone());
+
+        let mut mh = MusicHoard {
+            library_cache: left.clone(),
+            database_cache: right.clone(),
+            ..Default::default()
+        };
+
+        mh.collection = mh.merge_collections();
+    }
+
+    #[test]
+    #[should_panic(expected = "multiple primaries unsupported")]
+    fn merge_one_db_artist_to_two_lib_artists() {
+        let mut left = Collection::new();
+        let mut right = Collection::new();
+
+        let artist = Artist::new(ArtistId::new("Artist"));
+
+        left.push(artist.clone());
+        left.push(artist.clone());
+        right.push(artist.clone());
+
+        let mut mh = MusicHoard {
+            library_cache: left.clone(),
+            database_cache: right.clone(),
+            ..Default::default()
+        };
+
+        mh.collection = mh.merge_collections();
+    }
+
+    #[test]
+    fn merge_normalized_artist_names() {
+        let mut left = Collection::new();
+        let mut right = Collection::new();
+
+        left.push(Artist::new(ArtistId::new("Artist‐Name ‘Name’")));
+
+        right.push(Artist::new(ArtistId::new("arTist—naMe 'name’")));
+        right.push(Artist::new(ArtistId::new("Artist‐Name “Name”")));
+
+        // The first artist will be merged, the second will be added.
+        let mut expected = left.clone();
+        expected.push(right.last().unwrap().clone());
+        expected.sort_unstable();
+
+        let mut mh = MusicHoard {
+            library_cache: left.clone(),
+            database_cache: right.clone(),
+            ..Default::default()
+        };
+
+        mh.collection = mh.merge_collections();
+        assert_eq!(expected, mh.collection);
+    }
 }