Use types to enforce normalisation

src/core/collection/artist.rs

@@ -6,7 +6,7 @@ use std::{
 
 use crate::core::collection::{
     album::{Album, AlbumLibId},
-    merge::{Merge, MergeCollections},
+    merge::{Merge, MergeCollections, TitleMap},
     musicbrainz::{MbArtistRef, MbRefOption},
     string::{self, NormalString},
 };
@@ -65,8 +65,8 @@ impl Merge for Artist {
 struct MergeAlbums {
     primary_by_lib_id: HashMap<u32, Album>,
     primary_by_singleton: HashMap<NormalString, Album>,
-    primary_by_title: HashMap<NormalString, Vec<Album>>,
-    secondary_by_title: HashMap<NormalString, Vec<Album>>,
+    primary_by_title: TitleMap<Album>,
+    secondary_by_title: TitleMap<Album>,
     merged: Vec<Album>,
 }
 
@@ -104,16 +104,13 @@ impl MergeAlbums {
             self.merge_album_by_lib_id(secondary_album);
         }
         for (_, primary_album) in self.primary_by_lib_id.drain() {
-            self.primary_by_title
-                .entry(string::normalize_string(&primary_album.meta.id.title))
-                .or_default()
-                .push(primary_album);
+            self.primary_by_title.insert(
+                string::normalize_string(&primary_album.meta.id.title),
+                primary_album,
+            );
         }
         for (title, primary_album) in self.primary_by_singleton.drain() {
-            self.primary_by_title
-                .entry(title.clone())
-                .or_default()
-                .push(primary_album);
+            self.primary_by_title.insert(title, primary_album);
         }
     }
 
@@ -134,10 +131,10 @@ impl MergeAlbums {
         }
 
         secondary_album.meta.id.lib_id = AlbumLibId::None;
-        self.secondary_by_title
-            .entry(string::normalize_string(&secondary_album.meta.id.title))
-            .or_default()
-            .push(secondary_album);
+        self.secondary_by_title.insert(
+            string::normalize_string(&secondary_album.meta.id.title),
+            secondary_album,
+        );
     }
 }
 

src/core/collection/merge.rs

@@ -82,16 +82,35 @@ where
     }
 }
 
+#[derive(Debug)]
+pub struct TitleMap<T>(HashMap<NormalString, Vec<T>>);
+
+impl<T> Default for TitleMap<T> {
+    fn default() -> Self {
+        TitleMap(HashMap::default())
+    }
+}
+
+impl<T> TitleMap<T> {
+    pub fn new() -> Self {
+        TitleMap(HashMap::new())
+    }
+
+    pub fn insert(&mut self, key: NormalString, item: T) {
+        self.0.entry(key).or_default().push(item);
+    }
+
+    fn remove(&mut self, key: &NormalString) -> Option<Vec<T>> {
+        self.0.remove(key)
+    }
+}
+
 pub struct MergeCollections;
 
 impl MergeCollections {
-    pub fn merge_by_name<T, It>(mut primary: HashMap<NormalString, Vec<T>>, secondary: It) -> Vec<T>
-    where
-        T: Merge,
-        It: IntoIterator<Item = (NormalString, Vec<T>)>,
-    {
+    pub fn merge_by_name<T: Merge>(mut primary: TitleMap<T>, secondary: TitleMap<T>) -> Vec<T> {
         let mut merged = vec![];
-        for (title, mut secondary_items) in secondary.into_iter() {
+        for (title, mut secondary_items) in secondary.0.into_iter() {
             match primary.remove(&title) {
                 Some(mut primary_items) => {
                     // We do not support merging multiple items with same name yet. Support will be
@@ -105,7 +124,7 @@ impl MergeCollections {
                 None => merged.extend(secondary_items),
             }
         }
-        merged.extend(primary.into_values().flatten());
+        merged.extend(primary.0.into_values().flatten());
         merged
     }
 }

src/core/musichoard/base.rs

@@ -1,12 +1,9 @@
-use std::collections::HashMap;
-
 use crate::core::{
     collection::{
         album::{Album, AlbumId},
         artist::{Artist, ArtistId},
-        merge::MergeCollections,
-        string::{self, NormalString},
-        Collection,
+        merge::{MergeCollections, TitleMap},
+        string, Collection,
     },
     musichoard::{Error, MusicHoard},
 };
@@ -60,21 +57,15 @@ impl<Database, Library> IMusicHoardBasePrivate for MusicHoard<Database, Library>
     }
 
     fn merge_collections(&self) -> Collection {
-        let mut primary = HashMap::<NormalString, Vec<Artist>>::new();
-        let mut secondary = HashMap::<NormalString, Vec<Artist>>::new();
+        let mut primary = TitleMap::<Artist>::new();
+        let mut secondary = TitleMap::<Artist>::new();
 
         for artist in self.library_cache.iter().cloned() {
-            primary
-                .entry(string::normalize_string(&artist.meta.id.name))
-                .or_default()
-                .push(artist);
+            primary.insert(string::normalize_string(&artist.meta.id.name), artist);
         }
 
         for artist in self.database_cache.iter().cloned() {
-            secondary
-                .entry(string::normalize_string(&artist.meta.id.name))
-                .or_default()
-                .push(artist);
+            secondary.insert(string::normalize_string(&artist.meta.id.name), artist);
         }
 
         let mut collection = MergeCollections::merge_by_name(primary, secondary);