Return owned string from tag canonicalization.

Author: RillingDev

src/tag.rs

@@ -48,8 +48,8 @@ fn collect_tags(tags: &[Tag]) -> Tags {
 	tags.iter()
 		.map(|tag| {
 			let key = match tag.std_key {
-				Some(std_key) => std_key.canonical_tag_key().to_string(),
-				None => tag.key.canonical_tag_key().to_string(),
+				Some(std_key) => std_key.canonical_tag_key(),
+				None => tag.key.canonical_tag_key(),
 			};
 			(key, tag.value.to_string())
 		})

src/tag_key.rs

@@ -3,23 +3,23 @@ use std::sync::LazyLock;
 use symphonia::core::meta::StandardTagKey;
 
 pub trait CanonicalTagKey {
-	fn canonical_tag_key(&self) -> &str;
+	fn canonical_tag_key(&self) -> String;
 }
 
 static NONSTANDARD_TAG_MAPPING: LazyLock<HashMap<String, String>> = LazyLock::new(|| {
 	serde_json::from_str(include_str!("tag_key_mapping.json"))
 		.expect("Failed to parse tag mapping.")
 });
 impl CanonicalTagKey for str {
-	fn canonical_tag_key(&self) -> &str {
+	fn canonical_tag_key(&self) -> String {
 		NONSTANDARD_TAG_MAPPING
 			.get(self)
-			.map_or(self, |s| s.as_str())
+			.map_or(self.to_string(), |s| s.clone())
 	}
 }
 
 impl CanonicalTagKey for StandardTagKey {
-	fn canonical_tag_key(&self) -> &str {
+	fn canonical_tag_key(&self) -> String {
 		match self {
 			StandardTagKey::AcoustidFingerprint => "AcoustidFingerprint",
 			StandardTagKey::AcoustidId => "AcoustidId",
@@ -133,5 +133,6 @@ impl CanonicalTagKey for StandardTagKey {
 			StandardTagKey::Version => "Version",
 			StandardTagKey::Writer => "Writer",
 		}
+		.to_string()
 	}
 }