UUIDを分解する部分を修正し、テストも追加

以下のためuuidもアップデートする。
<uuid-rs/uuid#741>

Cargo.toml

@@ -80,7 +80,7 @@ tracing = "0.1.37"
 tracing-subscriber = "0.3.16"
 typetag = "0.2.5"
 url = "2.3.0"
-uuid = "1.4.0"
+uuid = "1.6.1"
 voicevox_core = { path = "crates/voicevox_core" }
 windows = "0.43.0"
 zip = "0.6.3"

crates/voicevox_core_java_api/Cargo.toml

@@ -18,6 +18,8 @@ derive_more.workspace = true
 easy-ext.workspace = true
 jni.workspace = true
 once_cell.workspace = true
+pretty_assertions = "1.3.0"
+rstest.workspace = true
 serde_json = { workspace = true, features = ["preserve_order"] }
 tracing = { workspace = true, features = ["log"] }
 tracing-subscriber = { workspace = true, features = ["env-filter"] }

crates/voicevox_core_java_api/src/common.rs

@@ -177,19 +177,47 @@ pub(crate) enum JavaApiError {
 #[ext(JNIEnvExt)]
 pub(crate) impl JNIEnv<'_> {
     fn new_uuid(&mut self, uuid: Uuid) -> jni::errors::Result<JObject<'_>> {
-        let uuid = uuid.as_u128();
-        let msbs = i64::try_from(uuid >> 64).expect("128 - 64 = 64").into();
-        let lsbs = (uuid as i64).into();
-        self.new_object("java/util/UUID", "(JJ)V", &[msbs, lsbs])
+        let (msbs, lsbs) = split_uuid(uuid);
+        self.new_object("java/util/UUID", "(JJ)V", &[msbs.into(), lsbs.into()])
     }
 
     fn get_uuid(&mut self, obj: &JObject<'_>) -> jni::errors::Result<Uuid> {
-        let mut get_bits = |name| {
-            let v = self.call_method(obj, name, "()J", &[])?.j()?;
-            Ok::<_, jni::errors::Error>(u128::from(v as u64))
-        };
+        let mut get_bits = |method_name| self.call_method(obj, method_name, "()J", &[])?.j();
         let msbs = get_bits("getMostSignificantBits")?;
         let lsbs = get_bits("getLeastSignificantBits")?;
-        Ok(Uuid::from_u128((msbs << 64) + lsbs))
+        Ok(construct_uuid(msbs, lsbs))
+    }
+}
+
+fn split_uuid(uuid: Uuid) -> (i64, i64) {
+    let uuid = uuid.as_u128();
+    let msbs = (uuid >> 64) as _;
+    let lsbs = uuid as _;
+    (msbs, lsbs)
+}
+
+fn construct_uuid(msbs: i64, lsbs: i64) -> Uuid {
+    return Uuid::from_u128((to_u128(msbs) << 64) + to_u128(lsbs));
+
+    fn to_u128(bits: i64) -> u128 {
+        (bits as u64).into()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use pretty_assertions::assert_eq;
+    use rstest::rstest;
+    use uuid::{uuid, Uuid};
+
+    #[rstest]
+    #[case(uuid!("a1a2a3a4-b1b2-c1c2-d1d2-e1e2e3e4e5e6"))]
+    #[case(uuid!("00000000-0000-0000-0000-000000000000"))]
+    #[case(uuid!("00000000-0000-0000-ffff-ffffffffffff"))]
+    #[case(uuid!("ffffffff-ffff-ffff-0000-000000000000"))]
+    #[case(uuid!("ffffffff-ffff-ffff-ffff-ffffffffffff"))]
+    fn uuid_conversion_works(#[case] uuid: Uuid) {
+        let (msbs, lsbs) = super::split_uuid(uuid);
+        assert_eq!(uuid, super::construct_uuid(msbs, lsbs));
     }
 }