src/core/collection/album.rs

@@ -5,7 +5,7 @@ use std::{
 
 use crate::core::collection::{
     merge::{Merge, MergeSorted, WithId},
-    musicbrainz::MbAlbumRef,
+    musicbrainz::{MbAlbumRef, MbRefOption},
     track::{Track, TrackFormat},
 };
 
@@ -22,7 +22,7 @@ pub struct AlbumMeta {
     pub id: AlbumId,
     pub date: AlbumDate,
     pub seq: AlbumSeq,
-    pub musicbrainz: Option<MbAlbumRef>,
+    pub musicbrainz: MbRefOption<MbAlbumRef>,
     pub primary_type: Option<AlbumPrimaryType>,
     pub secondary_types: Vec<AlbumSecondaryType>,
 }
@@ -186,7 +186,7 @@ impl AlbumMeta {
             id: id.into(),
             date: date.into(),
             seq: AlbumSeq::default(),
-            musicbrainz: None,
+            musicbrainz: MbRefOption::None,
             primary_type,
             secondary_types,
         }
@@ -364,7 +364,7 @@ mod tests {
 
         let mut album = Album::new(AlbumId::new("an album"), AlbumDate::default(), None, vec![]);
 
-        let mut expected: Option<MbAlbumRef> = None;
+        let mut expected: MbRefOption<MbAlbumRef> = MbRefOption::None;
         assert_eq!(album.meta.musicbrainz, expected);
 
         // Setting a URL on an album.

src/core/collection/artist.rs

@@ -7,7 +7,7 @@ use std::{
 use crate::core::collection::{
     album::Album,
     merge::{Merge, MergeCollections, WithId},
-    musicbrainz::MbArtistRef,
+    musicbrainz::{MbArtistRef, MbRefOption},
 };
 
 /// An artist.
@@ -22,7 +22,7 @@ pub struct Artist {
 pub struct ArtistMeta {
     pub id: ArtistId,
     pub sort: Option<ArtistId>,
-    pub musicbrainz: Option<MbArtistRef>,
+    pub musicbrainz: MbRefOption<MbArtistRef>,
     pub properties: HashMap<String, Vec<String>>,
 }
 
@@ -75,7 +75,7 @@ impl ArtistMeta {
         ArtistMeta {
             id: id.into(),
             sort: None,
-            musicbrainz: None,
+            musicbrainz: MbRefOption::None,
             properties: HashMap::new(),
         }
     }
@@ -255,7 +255,7 @@ mod tests {
     fn set_clear_musicbrainz_url() {
         let mut artist = Artist::new(ArtistId::new("an artist"));
 
-        let mut expected: Option<MbArtistRef> = None;
+        let mut expected: MbRefOption<MbArtistRef> = MbRefOption::None;
         assert_eq!(artist.meta.musicbrainz, expected);
 
         // Setting a URL on an artist.
@@ -417,7 +417,7 @@ mod tests {
         let left = FULL_COLLECTION[0].to_owned();
         let mut right = FULL_COLLECTION[1].to_owned();
         right.meta.id = left.meta.id.clone();
-        right.meta.musicbrainz = None;
+        right.meta.musicbrainz = MbRefOption::None;
         right.meta.properties = HashMap::new();
 
         let mut expected = left.clone();

src/core/collection/musicbrainz.rs

@@ -1,4 +1,4 @@
-use std::fmt::{Debug, Display};
+use std::{fmt, mem};
 
 use url::Url;
 use uuid::Uuid;
@@ -38,6 +38,30 @@ try_from_impl_for_mbid!(&str);
 try_from_impl_for_mbid!(&String);
 try_from_impl_for_mbid!(String);
 
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum MbRefOption<T> {
+    Some(T),
+    CannotHaveMbid,
+    None,
+}
+
+impl<T> MbRefOption<T> {
+    pub fn or(self, optb: MbRefOption<T>) -> MbRefOption<T> {
+        match self {
+            x @ MbRefOption::Some(_) => x,
+            MbRefOption::CannotHaveMbid | MbRefOption::None => optb,
+        }
+    }
+
+    pub fn replace(&mut self, value: T) -> MbRefOption<T> {
+        mem::replace(self, MbRefOption::Some(value))
+    }
+
+    pub fn take(&mut self) -> MbRefOption<T> {
+        mem::replace(self, MbRefOption::None)
+    }
+}
+
 #[derive(Clone, Debug, PartialEq, Eq)]
 struct MusicBrainzRef {
     mbid: Mbid,
@@ -142,7 +166,7 @@ impl MusicBrainzRef {
         MusicBrainzRef { mbid, url }
     }
 
-    fn invalid_url_error<U: Display>(url: U, entity: &'static str) -> Error {
+    fn invalid_url_error<U: fmt::Display>(url: U, entity: &'static str) -> Error {
         Error::UrlError(format!("invalid {entity} MusicBrainz URL: {url}"))
     }
 }

src/core/musichoard/database.rs

@@ -297,11 +297,14 @@ impl<Database: IDatabase, Library> MusicHoard<Database, Library> {
 mod tests {
     use mockall::{predicate, Sequence};
 
-    use crate::core::{
+    use crate::{
-        collection::{album::AlbumDate, artist::ArtistId},
+        collection::musicbrainz::MbRefOption,
-        interface::database::{self, MockIDatabase},
+        core::{
-        musichoard::{base::IMusicHoardBase, NoLibrary},
+            collection::{album::AlbumDate, artist::ArtistId},
-        testmod::FULL_COLLECTION,
+            interface::database::{self, MockIDatabase},
+            musichoard::{base::IMusicHoardBase, NoLibrary},
+            testmod::FULL_COLLECTION,
+        },
     };
 
     use super::*;
@@ -441,7 +444,7 @@ mod tests {
 
         assert!(music_hoard.add_artist(artist_id.clone()).is_ok());
 
-        let mut expected: Option<MbArtistRef> = None;
+        let mut expected: MbRefOption<MbArtistRef> = MbRefOption::None;
         assert_eq!(music_hoard.collection[0].meta.musicbrainz, expected);
 
         // Setting a URL on an artist not in the collection is an error.

src/core/testmod.rs

@@ -4,7 +4,7 @@ use std::collections::HashMap;
 use crate::core::collection::{
     album::{Album, AlbumId, AlbumMeta, AlbumPrimaryType, AlbumSeq},
     artist::{Artist, ArtistId, ArtistMeta},
-    musicbrainz::{MbAlbumRef, MbArtistRef},
+    musicbrainz::{MbAlbumRef, MbArtistRef, MbRefOption},
     track::{Track, TrackFormat, TrackId, TrackNum, TrackQuality},
 };
 use crate::testmod::*;

src/external/database/json/testmod.rs

@@ -1,10 +1,10 @@
 pub static DATABASE_JSON: &str = "{\
-    \"V20240828\":\
+    \"V20240924\":\
     [\
     {\
     \"name\":\"Album_Artist ‘A’\",\
     \"sort\":null,\
-    \"musicbrainz\":\"00000000-0000-0000-0000-000000000000\",\
+    \"musicbrainz\":{\"Some\":\"00000000-0000-0000-0000-000000000000\"},\
     \"properties\":{\
     \"MusicButler\":[\"https://www.musicbutler.io/artist-page/000000000\"],\
     \"Qobuz\":[\"https://www.qobuz.com/nl-nl/interpreter/artist-a/download-streaming-albums\"]\
@@ -12,11 +12,11 @@ pub static DATABASE_JSON: &str = "{\
     \"albums\":[\
     {\
     \"title\":\"album_title a.a\",\"seq\":1,\
-    \"musicbrainz\":\"00000000-0000-0000-0000-000000000000\",\
+    \"musicbrainz\":{\"Some\":\"00000000-0000-0000-0000-000000000000\"},\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     },\
     {\
-    \"title\":\"album_title a.b\",\"seq\":1,\"musicbrainz\":null,\
+    \"title\":\"album_title a.b\",\"seq\":1,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     }\
     ]\
@@ -24,7 +24,7 @@ pub static DATABASE_JSON: &str = "{\
     {\
     \"name\":\"Album_Artist ‘B’\",\
     \"sort\":null,\
-    \"musicbrainz\":\"11111111-1111-1111-1111-111111111111\",\
+    \"musicbrainz\":{\"Some\":\"11111111-1111-1111-1111-111111111111\"},\
     \"properties\":{\
     \"Bandcamp\":[\"https://artist-b.bandcamp.com/\"],\
     \"MusicButler\":[\
@@ -35,21 +35,21 @@ pub static DATABASE_JSON: &str = "{\
     },\
     \"albums\":[\
     {\
-    \"title\":\"album_title b.a\",\"seq\":1,\"musicbrainz\":null,\
+    \"title\":\"album_title b.a\",\"seq\":1,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     },\
     {\
     \"title\":\"album_title b.b\",\"seq\":3,\
-    \"musicbrainz\":\"11111111-1111-1111-1111-111111111111\",\
+    \"musicbrainz\":{\"Some\":\"11111111-1111-1111-1111-111111111111\"},\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     },\
     {\
     \"title\":\"album_title b.c\",\"seq\":2,\
-    \"musicbrainz\":\"11111111-1111-1111-1111-111111111112\",\
+    \"musicbrainz\":{\"Some\":\"11111111-1111-1111-1111-111111111112\"},\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     },\
     {\
-    \"title\":\"album_title b.d\",\"seq\":4,\"musicbrainz\":null,\
+    \"title\":\"album_title b.d\",\"seq\":4,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     }\
     ]\
@@ -57,15 +57,15 @@ pub static DATABASE_JSON: &str = "{\
     {\
     \"name\":\"The Album_Artist ‘C’\",\
     \"sort\":\"Album_Artist ‘C’, The\",\
-    \"musicbrainz\":\"11111111-1111-1111-1111-111111111111\",\
+    \"musicbrainz\":\"CannotHaveMbid\",\
     \"properties\":{},\
     \"albums\":[\
     {\
-    \"title\":\"album_title c.a\",\"seq\":0,\"musicbrainz\":null,\
+    \"title\":\"album_title c.a\",\"seq\":0,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     },\
     {\
-    \"title\":\"album_title c.b\",\"seq\":0,\"musicbrainz\":null,\
+    \"title\":\"album_title c.b\",\"seq\":0,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     }\
     ]\
@@ -73,15 +73,15 @@ pub static DATABASE_JSON: &str = "{\
     {\
     \"name\":\"Album_Artist ‘D’\",\
     \"sort\":null,\
-    \"musicbrainz\":null,\
+    \"musicbrainz\":\"None\",\
     \"properties\":{},\
     \"albums\":[\
     {\
-    \"title\":\"album_title d.a\",\"seq\":0,\"musicbrainz\":null,\
+    \"title\":\"album_title d.a\",\"seq\":0,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     },\
     {\
-    \"title\":\"album_title d.b\",\"seq\":0,\"musicbrainz\":null,\
+    \"title\":\"album_title d.b\",\"seq\":0,\"musicbrainz\":\"None\",\
     \"primary_type\":\"Album\",\"secondary_types\":[]\
     }\
     ]\

src/external/database/serde/common.rs

@@ -1,6 +1,17 @@
 use serde::{Deserialize, Serialize};
 
-use crate::core::collection::album::{AlbumPrimaryType, AlbumSecondaryType};
+use crate::{
+    collection::musicbrainz::MbRefOption,
+    core::collection::album::{AlbumPrimaryType, AlbumSecondaryType},
+};
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(remote = "MbRefOption")]
+pub enum MbRefOptionDef<T> {
+    Some(T),
+    CannotHaveMbid,
+    None,
+}
 
 #[derive(Debug, Deserialize, Serialize)]
 #[serde(remote = "AlbumPrimaryType")]

src/external/database/serde/deserialize.rs

@@ -3,7 +3,11 @@ use std::{collections::HashMap, fmt};
 use serde::{de::Visitor, Deserialize, Deserializer};
 
 use crate::{
-    collection::{album::AlbumMeta, artist::ArtistMeta, musicbrainz::Mbid},
+    collection::{
+        album::AlbumMeta,
+        artist::ArtistMeta,
+        musicbrainz::{MbAlbumRef, MbArtistRef, MbRefOption, Mbid},
+    },
     core::collection::{
         album::{Album, AlbumDate, AlbumId, AlbumSeq},
         artist::{Artist, ArtistId},
@@ -12,15 +16,17 @@ use crate::{
     external::database::serde::common::{SerdeAlbumPrimaryType, SerdeAlbumSecondaryType},
 };
 
+use super::common::MbRefOptionDef;
+
 #[derive(Debug, Deserialize)]
 pub enum DeserializeDatabase {
-    V20240828(Vec<DeserializeArtist>),
+    V20240924(Vec<DeserializeArtist>),
 }
 
 impl From<DeserializeDatabase> for Collection {
     fn from(database: DeserializeDatabase) -> Self {
         match database {
-            DeserializeDatabase::V20240828(collection) => {
+            DeserializeDatabase::V20240924(collection) => {
                 collection.into_iter().map(Into::into).collect()
             }
         }
@@ -31,7 +37,7 @@ impl From<DeserializeDatabase> for Collection {
 pub struct DeserializeArtist {
     name: String,
     sort: Option<String>,
-    musicbrainz: Option<DeserializeMbid>,
+    musicbrainz: DeserializeMbRefOption,
     properties: HashMap<String, Vec<String>>,
     albums: Vec<DeserializeAlbum>,
 }
@@ -40,14 +46,34 @@ pub struct DeserializeArtist {
 pub struct DeserializeAlbum {
     title: String,
     seq: u8,
-    musicbrainz: Option<DeserializeMbid>,
+    musicbrainz: DeserializeMbRefOption,
     primary_type: Option<SerdeAlbumPrimaryType>,
     secondary_types: Vec<SerdeAlbumSecondaryType>,
 }
 
+#[derive(Debug, Deserialize)]
+pub struct DeserializeMbRefOption(#[serde(with = "MbRefOptionDef")] MbRefOption<DeserializeMbid>);
+
 #[derive(Clone, Debug)]
 pub struct DeserializeMbid(Mbid);
 
+macro_rules! impl_from_for_mb_ref_option {
+    ($ref:ty) => {
+        impl From<DeserializeMbRefOption> for MbRefOption<$ref> {
+            fn from(value: DeserializeMbRefOption) -> Self {
+                match value.0 {
+                    MbRefOption::Some(val) => MbRefOption::Some(val.0.into()),
+                    MbRefOption::CannotHaveMbid => MbRefOption::CannotHaveMbid,
+                    MbRefOption::None => MbRefOption::None,
+                }
+            }
+        }
+    };
+}
+
+impl_from_for_mb_ref_option!(MbArtistRef);
+impl_from_for_mb_ref_option!(MbAlbumRef);
+
 impl From<DeserializeMbid> for Mbid {
     fn from(value: DeserializeMbid) -> Self {
         value.0
@@ -89,7 +115,7 @@ impl From<DeserializeArtist> for Artist {
             meta: ArtistMeta {
                 id: ArtistId::new(artist.name),
                 sort: artist.sort.map(ArtistId::new),
-                musicbrainz: artist.musicbrainz.map(Into::<Mbid>::into).map(Into::into),
+                musicbrainz: artist.musicbrainz.into(),
                 properties: artist.properties,
             },
             albums: artist.albums.into_iter().map(Into::into).collect(),
@@ -104,7 +130,7 @@ impl From<DeserializeAlbum> for Album {
                 id: AlbumId { title: album.title },
                 date: AlbumDate::default(),
                 seq: AlbumSeq(album.seq),
-                musicbrainz: album.musicbrainz.map(Into::<Mbid>::into).map(Into::into),
+                musicbrainz: album.musicbrainz.into(),
                 primary_type: album.primary_type.map(Into::into),
                 secondary_types: album.secondary_types.into_iter().map(Into::into).collect(),
             },

src/external/database/serde/serialize.rs

@@ -3,19 +3,21 @@ use std::collections::BTreeMap;
 use serde::Serialize;
 
 use crate::{
-    collection::musicbrainz::Mbid,
+    collection::musicbrainz::{MbRefOption, Mbid},
     core::collection::{album::Album, artist::Artist, musicbrainz::IMusicBrainzRef, Collection},
-    external::database::serde::common::{SerdeAlbumPrimaryType, SerdeAlbumSecondaryType},
+    external::database::serde::common::{
+        MbRefOptionDef, SerdeAlbumPrimaryType, SerdeAlbumSecondaryType,
+    },
 };
 
 #[derive(Debug, Serialize)]
 pub enum SerializeDatabase<'a> {
-    V20240828(Vec<SerializeArtist<'a>>),
+    V20240924(Vec<SerializeArtist<'a>>),
 }
 
 impl<'a> From<&'a Collection> for SerializeDatabase<'a> {
     fn from(collection: &'a Collection) -> Self {
-        SerializeDatabase::V20240828(collection.iter().map(Into::into).collect())
+        SerializeDatabase::V20240924(collection.iter().map(Into::into).collect())
     }
 }
 
@@ -23,7 +25,7 @@ impl<'a> From<&'a Collection> for SerializeDatabase<'a> {
 pub struct SerializeArtist<'a> {
     name: &'a str,
     sort: Option<&'a str>,
-    musicbrainz: Option<SerializeMbid<'a>>,
+    musicbrainz: SerializeMbRefOption<'a>,
     properties: BTreeMap<&'a str, &'a Vec<String>>,
     albums: Vec<SerializeAlbum<'a>>,
 }
@@ -32,14 +34,31 @@ pub struct SerializeArtist<'a> {
 pub struct SerializeAlbum<'a> {
     title: &'a str,
     seq: u8,
-    musicbrainz: Option<SerializeMbid<'a>>,
+    musicbrainz: SerializeMbRefOption<'a>,
     primary_type: Option<SerdeAlbumPrimaryType>,
     secondary_types: Vec<SerdeAlbumSecondaryType>,
 }
 
+#[derive(Debug, Serialize)]
+pub struct SerializeMbRefOption<'a>(
+    #[serde(with = "MbRefOptionDef")] MbRefOption<SerializeMbid<'a>>,
+);
+
 #[derive(Clone, Debug)]
 pub struct SerializeMbid<'a>(&'a Mbid);
 
+impl<'a, T: IMusicBrainzRef> From<&'a MbRefOption<T>> for SerializeMbRefOption<'a> {
+    fn from(value: &'a MbRefOption<T>) -> Self {
+        match value {
+            MbRefOption::Some(val) => {
+                SerializeMbRefOption(MbRefOption::Some(SerializeMbid(val.mbid())))
+            }
+            MbRefOption::CannotHaveMbid => SerializeMbRefOption(MbRefOption::CannotHaveMbid),
+            MbRefOption::None => SerializeMbRefOption(MbRefOption::None),
+        }
+    }
+}
+
 impl<'a> Serialize for SerializeMbid<'a> {
     fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
     where
@@ -54,11 +73,7 @@ impl<'a> From<&'a Artist> for SerializeArtist<'a> {
         SerializeArtist {
             name: &artist.meta.id.name,
             sort: artist.meta.sort.as_ref().map(|id| id.name.as_ref()),
-            musicbrainz: artist
+            musicbrainz: (&artist.meta.musicbrainz).into(),
-                .meta
-                .musicbrainz
-                .as_ref()
-                .map(|mbref| SerializeMbid(mbref.mbid())),
             properties: artist
                 .meta
                 .properties
@@ -75,11 +90,7 @@ impl<'a> From<&'a Album> for SerializeAlbum<'a> {
         SerializeAlbum {
             title: &album.meta.id.title,
             seq: album.meta.seq.0,
-            musicbrainz: album
+            musicbrainz: (&album.meta.musicbrainz).into(),
-                .meta
-                .musicbrainz
-                .as_ref()
-                .map(|mbref| SerializeMbid(mbref.mbid())),
             primary_type: album.meta.primary_type.map(Into::into),
             secondary_types: album
                 .meta

src/testmod/full.rs

@@ -7,7 +7,7 @@ macro_rules! full_collection {
                         name: "Album_Artist ‘A’".to_string(),
                     },
                     sort: None,
-                    musicbrainz: Some(MbArtistRef::from_url_str(
+                    musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                         "https://musicbrainz.org/artist/00000000-0000-0000-0000-000000000000"
                     ).unwrap()),
                     properties: HashMap::from([
@@ -29,7 +29,7 @@ macro_rules! full_collection {
                             },
                             date: 1998.into(),
                             seq: AlbumSeq(1),
-                            musicbrainz: Some(MbAlbumRef::from_url_str(
+                            musicbrainz: MbRefOption::Some(MbAlbumRef::from_url_str(
                                 "https://musicbrainz.org/release-group/00000000-0000-0000-0000-000000000000"
                             ).unwrap()),
                             primary_type: Some(AlbumPrimaryType::Album),
@@ -92,7 +92,7 @@ macro_rules! full_collection {
                             },
                             date: (2015, 4).into(),
                             seq: AlbumSeq(1),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },
@@ -129,7 +129,7 @@ macro_rules! full_collection {
                         name: "Album_Artist ‘B’".to_string(),
                     },
                     sort: None,
-                    musicbrainz: Some(MbArtistRef::from_url_str(
+                    musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                         "https://musicbrainz.org/artist/11111111-1111-1111-1111-111111111111"
                     ).unwrap()),
                     properties: HashMap::from([
@@ -155,7 +155,7 @@ macro_rules! full_collection {
                             },
                             date: (2003, 6, 6).into(),
                             seq: AlbumSeq(1),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },
@@ -194,7 +194,7 @@ macro_rules! full_collection {
                             },
                             date: 2008.into(),
                             seq: AlbumSeq(3),
-                            musicbrainz: Some(MbAlbumRef::from_url_str(
+                            musicbrainz: MbRefOption::Some(MbAlbumRef::from_url_str(
                                 "https://musicbrainz.org/release-group/11111111-1111-1111-1111-111111111111"
                             ).unwrap()),
                             primary_type: Some(AlbumPrimaryType::Album),
@@ -235,7 +235,7 @@ macro_rules! full_collection {
                             },
                             date: 2009.into(),
                             seq: AlbumSeq(2),
-                            musicbrainz: Some(MbAlbumRef::from_url_str(
+                            musicbrainz: MbRefOption::Some(MbAlbumRef::from_url_str(
                                 "https://musicbrainz.org/release-group/11111111-1111-1111-1111-111111111112"
                             ).unwrap()),
                             primary_type: Some(AlbumPrimaryType::Album),
@@ -276,7 +276,7 @@ macro_rules! full_collection {
                             },
                             date: 2015.into(),
                             seq: AlbumSeq(4),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },
@@ -318,9 +318,7 @@ macro_rules! full_collection {
                     sort: Some(ArtistId {
                         name: "Album_Artist ‘C’, The".to_string(),
                     }),
-                    musicbrainz: Some(MbArtistRef::from_url_str(
+                    musicbrainz: MbRefOption::CannotHaveMbid,
-                        "https://musicbrainz.org/artist/11111111-1111-1111-1111-111111111111"
-                    ).unwrap()),
                     properties: HashMap::new(),
                 },
                 albums: vec![
@@ -331,7 +329,7 @@ macro_rules! full_collection {
                             },
                             date: 1985.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },
@@ -370,7 +368,7 @@ macro_rules! full_collection {
                             },
                             date: 2018.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },
@@ -410,7 +408,7 @@ macro_rules! full_collection {
                         name: "Album_Artist ‘D’".to_string(),
                     },
                     sort: None,
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     properties: HashMap::new(),
                 },
                 albums: vec![
@@ -421,7 +419,7 @@ macro_rules! full_collection {
                             },
                             date: 1995.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },
@@ -460,7 +458,7 @@ macro_rules! full_collection {
                             },
                             date: 2028.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: Some(AlbumPrimaryType::Album),
                             secondary_types: vec![],
                         },

src/testmod/library.rs

@@ -8,7 +8,7 @@ macro_rules! library_collection {
                         name: "Album_Artist ‘A’".to_string(),
                     },
                     sort: None,
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     properties: HashMap::new(),
                 },
                 albums: vec![
@@ -19,7 +19,7 @@ macro_rules! library_collection {
                             },
                             date: 1998.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -80,7 +80,7 @@ macro_rules! library_collection {
                             },
                             date: (2015, 4).into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -117,7 +117,7 @@ macro_rules! library_collection {
                         name: "Album_Artist ‘B’".to_string(),
                     },
                     sort: None,
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     properties: HashMap::new(),
                 },
                 albums: vec![
@@ -128,7 +128,7 @@ macro_rules! library_collection {
                             },
                             date: (2003, 6, 6).into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -167,7 +167,7 @@ macro_rules! library_collection {
                             },
                             date: 2008.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -206,7 +206,7 @@ macro_rules! library_collection {
                             },
                             date: 2009.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -245,7 +245,7 @@ macro_rules! library_collection {
                             },
                             date: 2015.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -287,7 +287,7 @@ macro_rules! library_collection {
                     sort: Some(ArtistId {
                         name: "Album_Artist ‘C’, The".to_string(),
                     }),
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     properties: HashMap::new(),
                 },
                 albums: vec![
@@ -298,7 +298,7 @@ macro_rules! library_collection {
                             },
                             date: 1985.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -337,7 +337,7 @@ macro_rules! library_collection {
                             },
                             date: 2018.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -377,7 +377,7 @@ macro_rules! library_collection {
                         name: "Album_Artist ‘D’".to_string(),
                     },
                     sort: None,
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     properties: HashMap::new(),
                 },
                 albums: vec![
@@ -388,7 +388,7 @@ macro_rules! library_collection {
                             },
                             date: 1995.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },
@@ -427,7 +427,7 @@ macro_rules! library_collection {
                             },
                             date: 2028.into(),
                             seq: AlbumSeq(0),
-                            musicbrainz: None,
+                            musicbrainz: MbRefOption::None,
                             primary_type: None,
                             secondary_types: vec![],
                         },

src/tui/app/machine/fetch_state.rs

@@ -6,7 +6,7 @@ use std::{
 use musichoard::collection::{
     album::AlbumMeta,
     artist::{Artist, ArtistMeta},
-    musicbrainz::{IMusicBrainzRef, Mbid},
+    musicbrainz::{IMusicBrainzRef, MbRefOption, Mbid},
 };
 
 use crate::tui::{
@@ -35,9 +35,8 @@ impl FetchState {
 
     fn try_recv(&mut self) -> Result<MbApiResult, TryRecvError> {
         if let Some(lookup_rx) = &self.lookup_rx {
-            let result = lookup_rx.try_recv();
+            match lookup_rx.try_recv() {
-            match result {
+                x @ Ok(_) | x @ Err(TryRecvError::Empty) => return x,
-                Ok(_) | Err(TryRecvError::Empty) => return result,
                 Err(TryRecvError::Disconnected) => {
                     self.lookup_rx.take();
                 }
@@ -142,15 +141,16 @@ impl AppMachine<FetchState> {
         artist: &Artist,
     ) -> Result<(), DaemonError> {
         let requests = match artist.meta.musicbrainz {
-            Some(ref arid) => {
+            MbRefOption::Some(ref arid) => {
                 let arid = arid.mbid();
                 let albums = artist.albums.iter();
                 albums
-                    .filter(|album| album.meta.musicbrainz.is_none())
+                    .filter(|album| matches!(album.meta.musicbrainz, MbRefOption::None))
                     .map(|album| MbParams::search_release_group(arid.clone(), album.meta.clone()))
                     .collect()
             }
-            None => VecDeque::from([MbParams::search_artist(artist.meta.clone())]),
+            MbRefOption::CannotHaveMbid => return Ok(()),
+            MbRefOption::None => VecDeque::from([MbParams::search_artist(artist.meta.clone())]),
         };
         musicbrainz.submit_background_job(result_sender, requests)
     }
@@ -379,6 +379,20 @@ mod tests {
         AppMachine::app_lookup_artist(inner, fetch, &artist, mbid());
     }
 
+    #[test]
+    fn fetch_artist_cannot_have_mbid() {
+        let music_hoard = music_hoard(COLLECTION.to_owned());
+        let inner = inner(music_hoard);
+
+        // Use third artist to match the expectation.
+        let browse = AppMachine::browse_state(inner);
+        let browse = browse.increment_selection(Delta::Line).unwrap_browse();
+        let app = browse.increment_selection(Delta::Line);
+
+        let app = app.unwrap_browse().fetch_musicbrainz();
+        assert!(matches!(app, AppState::Match(_)));
+    }
+
     #[test]
     fn fetch_artist_job_sender_err() {
         let mut mb_job_sender = MockIMbJobSender::new();

src/tui/lib/external/musicbrainz/api/mod.rs

@@ -6,7 +6,7 @@ use musichoard::{
     collection::{
         album::{AlbumDate, AlbumMeta, AlbumSeq},
         artist::{ArtistId, ArtistMeta},
-        musicbrainz::Mbid,
+        musicbrainz::{MbRefOption, Mbid},
     },
     external::musicbrainz::{
         api::{
@@ -100,7 +100,7 @@ fn from_lookup_artist_response(entity: LookupArtistResponse) -> Lookup<ArtistMet
         item: ArtistMeta {
             id: entity.meta.name,
             sort,
-            musicbrainz: Some(entity.meta.id.into()),
+            musicbrainz: MbRefOption::Some(entity.meta.id.into()),
             properties: HashMap::new(),
         },
         disambiguation: entity.meta.disambiguation,
@@ -113,7 +113,7 @@ fn from_lookup_release_group_response(entity: LookupReleaseGroupResponse) -> Loo
             id: entity.meta.title,
             date: entity.meta.first_release_date,
             seq: AlbumSeq::default(),
-            musicbrainz: Some(entity.meta.id.into()),
+            musicbrainz: MbRefOption::Some(entity.meta.id.into()),
             primary_type: Some(entity.meta.primary_type),
             secondary_types: entity.meta.secondary_types.unwrap_or_default(),
         },
@@ -130,7 +130,7 @@ fn from_search_artist_response_artist(entity: SearchArtistResponseArtist) -> Mat
         item: ArtistMeta {
             id: entity.meta.name,
             sort,
-            musicbrainz: Some(entity.meta.id.into()),
+            musicbrainz: MbRefOption::Some(entity.meta.id.into()),
             properties: HashMap::new(),
         },
         disambiguation: entity.meta.disambiguation,
@@ -146,7 +146,7 @@ fn from_search_release_group_response_release_group(
             id: entity.meta.title,
             date: entity.meta.first_release_date,
             seq: AlbumSeq::default(),
-            musicbrainz: Some(entity.meta.id.into()),
+            musicbrainz: MbRefOption::Some(entity.meta.id.into()),
             primary_type: Some(entity.meta.primary_type),
             secondary_types: entity.meta.secondary_types.unwrap_or_default(),
         },

src/tui/lib/external/musicbrainz/daemon/mod.rs

@@ -316,7 +316,7 @@ mod tests {
     use musichoard::collection::{
         album::AlbumMeta,
         artist::ArtistMeta,
-        musicbrainz::{IMusicBrainzRef, Mbid},
+        musicbrainz::{IMusicBrainzRef, MbRefOption, Mbid},
     };
 
     use crate::tui::{
@@ -327,6 +327,21 @@ mod tests {
 
     use super::*;
 
+    fn mb_ref_opt_unwrap<T>(opt: MbRefOption<T>) -> T {
+        match opt {
+            MbRefOption::Some(val) => val,
+            _ => panic!(),
+        }
+    }
+
+    fn mb_ref_opt_as_ref<T>(opt: &MbRefOption<T>) -> MbRefOption<&T> {
+        match *opt {
+            MbRefOption::Some(ref x) => MbRefOption::Some(x),
+            MbRefOption::CannotHaveMbid => MbRefOption::CannotHaveMbid,
+            MbRefOption::None => MbRefOption::None,
+        }
+    }
+
     fn musicbrainz() -> MockIMusicBrainz {
         MockIMusicBrainz::new()
     }
@@ -403,8 +418,8 @@ mod tests {
     }
 
     fn search_albums_requests() -> VecDeque<MbParams> {
-        let mbref = COLLECTION[1].meta.musicbrainz.as_ref();
+        let mbref = mb_ref_opt_as_ref(&COLLECTION[1].meta.musicbrainz);
-        let arid = mbref.unwrap().mbid().clone();
+        let arid = mb_ref_opt_unwrap(mbref).mbid().clone();
 
         let album_1 = COLLECTION[1].albums[0].meta.clone();
         let album_4 = COLLECTION[1].albums[3].meta.clone();
@@ -416,8 +431,8 @@ mod tests {
     }
 
     fn album_arid_expectation() -> Mbid {
-        let mbref = COLLECTION[1].meta.musicbrainz.as_ref();
+        let mbref = mb_ref_opt_as_ref(&COLLECTION[1].meta.musicbrainz);
-        mbref.unwrap().mbid().clone()
+        mb_ref_opt_unwrap(mbref).mbid().clone()
     }
 
     fn search_album_expectations_1() -> (AlbumMeta, Vec<Match<AlbumMeta>>) {

src/tui/testmod.rs

@@ -3,7 +3,7 @@ use std::collections::HashMap;
 use musichoard::collection::{
     album::{Album, AlbumId, AlbumMeta, AlbumPrimaryType, AlbumSeq},
     artist::{Artist, ArtistId, ArtistMeta},
-    musicbrainz::{MbAlbumRef, MbArtistRef},
+    musicbrainz::{MbAlbumRef, MbArtistRef, MbRefOption},
     track::{Track, TrackFormat, TrackId, TrackNum, TrackQuality},
 };
 use once_cell::sync::Lazy;

src/tui/ui/display.rs

@@ -1,6 +1,7 @@
 use musichoard::collection::{
     album::{AlbumDate, AlbumMeta, AlbumPrimaryType, AlbumSecondaryType, AlbumSeq, AlbumStatus},
     artist::ArtistMeta,
+    musicbrainz::{IMusicBrainzRef, MbRefOption},
     track::{TrackFormat, TrackQuality},
 };
 
@@ -30,6 +31,14 @@ impl UiDisplay {
         }
     }
 
+    pub fn display_mb_ref_option_as_url<T: IMusicBrainzRef>(option: &MbRefOption<T>) -> &str {
+        match option {
+            MbRefOption::Some(val) => val.url().as_str(),
+            MbRefOption::CannotHaveMbid => "cannot have a MusicBrainz identifier",
+            MbRefOption::None => "",
+        }
+    }
+
     pub fn display_type(
         primary: &Option<AlbumPrimaryType>,
         secondary: &Vec<AlbumSecondaryType>,

src/tui/ui/info_state.rs

@@ -1,8 +1,10 @@
 use std::collections::HashMap;
 
-use musichoard::collection::{album::Album, artist::Artist, musicbrainz::IMusicBrainzRef};
+use musichoard::collection::{album::Album, artist::Artist};
 use ratatui::widgets::{ListState, Paragraph};
 
+use super::display::UiDisplay;
+
 struct InfoOverlay;
 
 impl InfoOverlay {
@@ -74,7 +76,7 @@ impl<'a> ArtistOverlay<'a> {
              Properties: {}",
             artist.map(|a| a.meta.id.name.as_str()).unwrap_or(""),
             artist
-                .and_then(|a| a.meta.musicbrainz.as_ref().map(|mb| mb.url().as_str()))
+                .and_then(|a| Some(UiDisplay::display_mb_ref_option_as_url(&a.meta.musicbrainz)))
                 .unwrap_or(""),
             Self::opt_hashmap_to_string(
                 artist.map(|a| &a.meta.properties),
@@ -102,7 +104,7 @@ impl<'a> AlbumOverlay<'a> {
              MusicBrainz: {}",
             album.map(|a| a.meta.id.title.as_str()).unwrap_or(""),
             album
-                .and_then(|a| a.meta.musicbrainz.as_ref().map(|mb| mb.url().as_str()))
+                .and_then(|a| Some(UiDisplay::display_mb_ref_option_as_url(&a.meta.musicbrainz)))
                 .unwrap_or(""),
         ));
 

src/tui/ui/mod.rs

@@ -305,7 +305,15 @@ mod tests {
 
         draw_test_suite(artists, &mut selection);
 
+        // Change the artist (which cannot have a MBID).
+        selection.increment_selection(artists, Delta::Line);
+        selection.increment_selection(artists, Delta::Line);
+
+        draw_test_suite(artists, &mut selection);
+
         // Change the track (which has a different track format).
+        selection.decrement_selection(artists, Delta::Line);
+        selection.decrement_selection(artists, Delta::Line);
         selection.increment_category();
         selection.increment_category();
         selection.increment_selection(artists, Delta::Line);

tests/files/database/database.json

@@ -1 +1 @@
-{"V20240828":[{"name":"Аркона","sort":"Arkona","musicbrainz":"baad262d-55ef-427a-83c7-f7530964f212","properties":{"Bandcamp":["https://arkonamoscow.bandcamp.com/"],"MusicButler":["https://www.musicbutler.io/artist-page/283448581"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/arkona/download-streaming-albums"]},"albums":[{"title":"Slovo","seq":0,"musicbrainz":null,"primary_type":"Album","secondary_types":[]}]},{"name":"Eluveitie","sort":null,"musicbrainz":"8000598a-5edb-401c-8e6d-36b167feaf38","properties":{"MusicButler":["https://www.musicbutler.io/artist-page/269358403"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/eluveitie/download-streaming-albums"]},"albums":[{"title":"Vên [re‐recorded]","seq":0,"musicbrainz":null,"primary_type":"Ep","secondary_types":[]},{"title":"Slania","seq":0,"musicbrainz":null,"primary_type":"Album","secondary_types":[]}]},{"name":"Frontside","sort":null,"musicbrainz":"3a901353-fccd-4afd-ad01-9c03f451b490","properties":{"MusicButler":["https://www.musicbutler.io/artist-page/826588800"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/frontside/download-streaming-albums"]},"albums":[{"title":"…nasze jest królestwo, potęga i chwała na wieki…","seq":0,"musicbrainz":null,"primary_type":"Album","secondary_types":[]}]},{"name":"Heaven’s Basement","sort":"Heaven’s Basement","musicbrainz":"c2c4d56a-d599-4a18-bd2f-ae644e2198cc","properties":{"MusicButler":["https://www.musicbutler.io/artist-page/291158685"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/heaven-s-basement/download-streaming-albums"]},"albums":[{"title":"Paper Plague","seq":0,"musicbrainz":null,"primary_type":null,"secondary_types":[]},{"title":"Unbreakable","seq":0,"musicbrainz":null,"primary_type":"Album","secondary_types":[]}]},{"name":"Metallica","sort":null,"musicbrainz":"65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab","properties":{"MusicButler":["https://www.musicbutler.io/artist-page/3996865"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/metallica/download-streaming-albums"]},"albums":[{"title":"Ride the Lightning","seq":0,"musicbrainz":null,"primary_type":"Album","secondary_types":[]},{"title":"S&M","seq":0,"musicbrainz":null,"primary_type":"Album","secondary_types":["Live"]}]}]}
+{"V20240924":[{"name":"Аркона","sort":"Arkona","musicbrainz":{"Some":"baad262d-55ef-427a-83c7-f7530964f212"},"properties":{"Bandcamp":["https://arkonamoscow.bandcamp.com/"],"MusicButler":["https://www.musicbutler.io/artist-page/283448581"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/arkona/download-streaming-albums"]},"albums":[{"title":"Slovo","seq":0,"musicbrainz":"None","primary_type":"Album","secondary_types":[]}]},{"name":"Eluveitie","sort":null,"musicbrainz":{"Some":"8000598a-5edb-401c-8e6d-36b167feaf38"},"properties":{"MusicButler":["https://www.musicbutler.io/artist-page/269358403"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/eluveitie/download-streaming-albums"]},"albums":[{"title":"Vên [re‐recorded]","seq":0,"musicbrainz":"None","primary_type":"Ep","secondary_types":[]},{"title":"Slania","seq":0,"musicbrainz":"None","primary_type":"Album","secondary_types":[]}]},{"name":"Frontside","sort":null,"musicbrainz":{"Some":"3a901353-fccd-4afd-ad01-9c03f451b490"},"properties":{"MusicButler":["https://www.musicbutler.io/artist-page/826588800"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/frontside/download-streaming-albums"]},"albums":[{"title":"…nasze jest królestwo, potęga i chwała na wieki…","seq":0,"musicbrainz":"None","primary_type":"Album","secondary_types":[]}]},{"name":"Heaven’s Basement","sort":"Heaven’s Basement","musicbrainz":{"Some":"c2c4d56a-d599-4a18-bd2f-ae644e2198cc"},"properties":{"MusicButler":["https://www.musicbutler.io/artist-page/291158685"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/heaven-s-basement/download-streaming-albums"]},"albums":[{"title":"Paper Plague","seq":0,"musicbrainz":"None","primary_type":null,"secondary_types":[]},{"title":"Unbreakable","seq":0,"musicbrainz":"None","primary_type":"Album","secondary_types":[]}]},{"name":"Metallica","sort":null,"musicbrainz":{"Some":"65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab"},"properties":{"MusicButler":["https://www.musicbutler.io/artist-page/3996865"],"Qobuz":["https://www.qobuz.com/nl-nl/interpreter/metallica/download-streaming-albums"]},"albums":[{"title":"Ride the Lightning","seq":0,"musicbrainz":"None","primary_type":"Album","secondary_types":[]},{"title":"S&M","seq":0,"musicbrainz":"None","primary_type":"Album","secondary_types":["Live"]}]}]}

tests/testlib.rs

@@ -4,7 +4,7 @@ use std::collections::HashMap;
 use musichoard::collection::{
     album::{Album, AlbumId, AlbumMeta, AlbumPrimaryType, AlbumSecondaryType, AlbumSeq},
     artist::{Artist, ArtistId, ArtistMeta},
-    musicbrainz::MbArtistRef,
+    musicbrainz::{MbArtistRef, MbRefOption},
     track::{Track, TrackFormat, TrackId, TrackNum, TrackQuality},
     Collection,
 };
@@ -19,7 +19,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                 sort: Some(ArtistId{
                     name: String::from("Arkona")
                 }),
-                musicbrainz: Some(MbArtistRef::from_url_str(
+                musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                     "https://musicbrainz.org/artist/baad262d-55ef-427a-83c7-f7530964f212"
                 ).unwrap()),
                 properties: HashMap::from([
@@ -41,7 +41,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     },
                     date: 2011.into(),
                     seq: AlbumSeq(0),
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     primary_type: Some(AlbumPrimaryType::Album),
                     secondary_types: vec![],
                 },
@@ -209,7 +209,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     name: String::from("Eluveitie"),
                 },
                 sort: None,
-                musicbrainz: Some(MbArtistRef::from_url_str(
+                musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                     "https://musicbrainz.org/artist/8000598a-5edb-401c-8e6d-36b167feaf38"
                 ).unwrap()),
                 properties: HashMap::from([
@@ -229,7 +229,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                         },
                         date: 2004.into(),
                         seq: AlbumSeq(0),
-                        musicbrainz: None,
+                        musicbrainz: MbRefOption::None,
                         primary_type: Some(AlbumPrimaryType::Ep),
                         secondary_types: vec![],
                     },
@@ -309,7 +309,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                         },
                         date: 2008.into(),
                         seq: AlbumSeq(0),
-                        musicbrainz: None,
+                        musicbrainz: MbRefOption::None,
                         primary_type: Some(AlbumPrimaryType::Album),
                         secondary_types: vec![],
                     },
@@ -456,7 +456,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     name: String::from("Frontside"),
                 },
                 sort: None,
-                musicbrainz: Some(MbArtistRef::from_url_str(
+                musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                     "https://musicbrainz.org/artist/3a901353-fccd-4afd-ad01-9c03f451b490"
                 ).unwrap()),
                 properties: HashMap::from([
@@ -475,7 +475,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     },
                     date: 2001.into(),
                     seq: AlbumSeq(0),
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     primary_type: Some(AlbumPrimaryType::Album),
                     secondary_types: vec![],
                 },
@@ -612,7 +612,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                 sort: Some(ArtistId {
                     name: String::from("Heaven’s Basement"),
                 }),
-                musicbrainz: Some(MbArtistRef::from_url_str(
+                musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                     "https://musicbrainz.org/artist/c2c4d56a-d599-4a18-bd2f-ae644e2198cc"
                 ).unwrap()),
                 properties: HashMap::from([
@@ -631,7 +631,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     },
                     date: 2011.into(),
                     seq: AlbumSeq(0),
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     primary_type: None,
                     secondary_types: vec![],
                 },
@@ -655,7 +655,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     },
                     date: 2011.into(),
                     seq: AlbumSeq(0),
-                    musicbrainz: None,
+                    musicbrainz: MbRefOption::None,
                     primary_type: Some(AlbumPrimaryType::Album),
                     secondary_types: vec![],
                 },
@@ -746,7 +746,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                     name: String::from("Metallica"),
                 },
                 sort: None,
-                musicbrainz: Some(MbArtistRef::from_url_str(
+                musicbrainz: MbRefOption::Some(MbArtistRef::from_url_str(
                     "https://musicbrainz.org/artist/65f4f0c5-ef9e-490c-aee3-909e7ae6b2ab"
                 ).unwrap()),
                 properties: HashMap::from([
@@ -766,7 +766,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                         },
                         date: 1984.into(),
                         seq: AlbumSeq(0),
-                        musicbrainz: None,
+                        musicbrainz: MbRefOption::None,
                         primary_type: Some(AlbumPrimaryType::Album),
                         secondary_types: vec![],
                     },
@@ -868,7 +868,7 @@ pub static COLLECTION: Lazy<Vec<Artist>> = Lazy::new(|| -> Collection {
                         },
                         date: 1999.into(),
                         seq: AlbumSeq(0),
-                        musicbrainz: None,
+                        musicbrainz: MbRefOption::None,
                         primary_type: Some(AlbumPrimaryType::Album),
                         secondary_types: vec![AlbumSecondaryType::Live],
                     },