[Rust]簡単なテストコードとtestingライブラリの導入

.github/workflows/test.yml

@@ -1,5 +1,5 @@
 name: test workflow
-on: [push]
+on: [push, pull_request]
 jobs:
   rust-lint:
     runs-on: ubuntu-latest

crates/voicevox_core/Cargo.toml

@@ -13,5 +13,9 @@ derive-new = "0.5.9"
 once_cell = "1.10.0"
 thiserror = "1.0.31"
 
+[dev-dependencies]
+rstest = "0.12.0"
+pretty_assertions = "1.2.1"
+
 [build-dependencies]
 cbindgen = "0.23.0"

crates/voicevox_core/src/c_export.rs

@@ -11,6 +11,7 @@ use std::sync::Mutex;
  */
 
 #[repr(C)]
+#[derive(Debug, PartialEq)]
 #[allow(non_camel_case_types)]
 pub enum VoicevoxResultCode {
     // C でのenum定義に合わせて大文字で定義している
@@ -214,3 +215,20 @@ pub extern "C" fn voicevox_error_result_to_message(
 ) -> *const c_char {
     internal::voicevox_error_result_to_message(result_code).as_ptr() as *const c_char
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pretty_assertions::assert_eq;
+
+    #[rstest]
+    #[case(Ok(()), VoicevoxResultCode::VOICEVOX_RESULT_SUCCEED)]
+    #[case(
+        Err(Error::NotLoadedOpenjtalkDict),
+        VoicevoxResultCode::VOICEVOX_RESULT_NOT_LOADED_OPENJTALK_DICT
+    )]
+    fn convert_result_works(#[case] result: Result<()>, #[case] expected: VoicevoxResultCode) {
+        let (_, actual) = convert_result(result);
+        assert_eq!(expected, actual);
+    }
+}

crates/voicevox_core/src/lib.rs

@@ -5,3 +5,6 @@ mod result;
 
 use error::*;
 use result::*;
+
+#[cfg(test)]
+use rstest::*;