Sort the collection

src/lib.rs

@@ -39,8 +39,24 @@ pub struct Track {
     pub quality: Quality,
 }
 
+impl PartialOrd for Track {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        let id = (&self.number, &self.title);
+        let other_id = (&other.number, &other.title);
+        id.partial_cmp(&other_id)
+    }
+}
+
+impl Ord for Track {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        let id = (&self.number, &self.title);
+        let other_id = (&other.number, &other.title);
+        id.cmp(&other_id)
+    }
+}
+
 /// The album identifier.
-#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, PartialOrd, Ord, Eq, Hash)]
 pub struct AlbumId {
     pub year: u32,
     pub title: String,
@@ -53,8 +69,20 @@ pub struct Album {
     pub tracks: Vec<Track>,
 }
 
+impl PartialOrd for Album {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        self.id.partial_cmp(&other.id)
+    }
+}
+
+impl Ord for Album {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.id.cmp(&other.id)
+    }
+}
+
 /// The artist identifier.
-#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq, Hash)]
+#[derive(Clone, Debug, Deserialize, Serialize, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub struct ArtistId {
     pub name: String,
 }
@@ -66,6 +94,18 @@ pub struct Artist {
     pub albums: Vec<Album>,
 }
 
+impl PartialOrd for Artist {
+    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
+        self.id.partial_cmp(&other.id)
+    }
+}
+
+impl Ord for Artist {
+    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
+        self.id.cmp(&other.id)
+    }
+}
+
 /// The collection type. Currently, a collection is a list of artists.
 pub type Collection = Vec<Artist>;
 
@@ -122,6 +162,7 @@ impl<LIB: ILibrary, DB: IDatabase> MusicHoard<LIB, DB> {
     pub fn rescan_library(&mut self) -> Result<(), Error> {
         let items = self.library.list(&Query::new())?;
         self.collection = Self::items_to_artists(items);
+        Self::sort(&mut self.collection);
         Ok(())
     }
 
@@ -134,6 +175,16 @@ impl<LIB: ILibrary, DB: IDatabase> MusicHoard<LIB, DB> {
         &self.collection
     }
 
+    fn sort(collection: &mut [Artist]) {
+        collection.sort_unstable();
+        for artist in collection.iter_mut() {
+            artist.albums.sort_unstable();
+            for album in artist.albums.iter_mut() {
+                album.tracks.sort_unstable();
+            }
+        }
+    }
+
     fn items_to_artists(items: Vec<Item>) -> Vec<Artist> {
         let mut artists: Vec<Artist> = vec![];
         let mut album_ids = HashMap::<ArtistId, HashSet<AlbumId>>::new();
@@ -287,23 +338,8 @@ mod tests {
 
         let mut music_hoard = MusicHoard::new(library, database);
 
-        let mut expected = COLLECTION.to_owned();
-
-        // Putting the last track first will make the entire artist come first in the output.
-        expected.rotate_right(1);
-
-        // Same applies to that artists' albums.
-        expected[0].albums.rotate_right(1);
-
-        // Same applies to that album's tracks.
-        expected[0].albums[0].tracks.rotate_right(1);
-
-        // And the original first album's (now the first album of the second artist) tracks first
-        // track comes last as it will only get picked up at the end.
-        expected[1].albums[0].tracks.rotate_left(1);
-
         music_hoard.rescan_library().unwrap();
-        assert_eq!(music_hoard.get_collection(), &expected);
+        assert_eq!(music_hoard.get_collection(), &*COLLECTION);
     }
 
     #[test]