sound: add init_logger() helper for testing

The init_logger() function gets compiled in tests only, and serves to
initialize logging only once per test thread.

Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

staging/vhost-device-sound/src/audio_backends/null.rs

@@ -34,6 +34,7 @@ mod tests {
 
     #[test]
     fn test_null_backend_write() {
+        crate::init_logger();
         let streams = Arc::new(RwLock::new(vec![Stream::default()]));
         let null_backend = NullBackend::new(streams.clone());
 
@@ -45,6 +46,7 @@ mod tests {
 
     #[test]
     fn test_null_backend_read() {
+        crate::init_logger();
         let streams = Arc::new(RwLock::new(vec![Stream::default()]));
         let null_backend = NullBackend::new(streams.clone());
 

staging/vhost-device-sound/src/audio_backends/pipewire.rs

@@ -575,6 +575,7 @@ mod tests {
 
     #[test]
     fn test_pipewire_backend_success() {
+        crate::init_logger();
         let streams = Arc::new(RwLock::new(vec![Stream::default()]));
         let stream_params = streams.clone();
 
@@ -603,6 +604,7 @@ mod tests {
 
     #[test]
     fn test_pipewire_backend_invalid_stream() {
+        crate::init_logger();
         let stream_params = Arc::new(RwLock::new(vec![]));
 
         let _test_harness = PipewireTestHarness::new();

staging/vhost-device-sound/src/device.rs

@@ -827,6 +827,7 @@ mod tests {
 
     #[test]
     fn test_sound_thread_success() {
+        crate::init_logger();
         let config = SoundConfig::new(SOCKET_PATH.to_string(), false, BackendType::Null);
 
         let chmaps = Arc::new(RwLock::new(vec![]));
@@ -921,6 +922,7 @@ mod tests {
 
     #[test]
     fn test_sound_thread_failure() {
+        crate::init_logger();
         let config = SoundConfig::new(SOCKET_PATH.to_string(), false, BackendType::Null);
 
         let chmaps = Arc::new(RwLock::new(vec![]));
@@ -995,6 +997,7 @@ mod tests {
 
     #[test]
     fn test_sound_backend() {
+        crate::init_logger();
         let test_dir = tempdir().expect("Could not create a temp test directory.");
         let socket_path = test_dir.path().join(SOCKET_PATH).display().to_string();
         let config = SoundConfig::new(socket_path, false, BackendType::Null);
@@ -1069,6 +1072,7 @@ mod tests {
 
     #[test]
     fn test_sound_backend_failures() {
+        crate::init_logger();
         let test_dir = tempdir().expect("Could not create a temp test directory.");
 
         let socket_path = test_dir

staging/vhost-device-sound/src/lib.rs

@@ -30,6 +30,12 @@
     clippy::significant_drop_tightening
 )]
 
+#[cfg(test)]
+pub fn init_logger() {
+    std::env::set_var("RUST_LOG", "trace");
+    let _ = env_logger::builder().is_test(true).try_init();
+}
+
 pub mod audio_backends;
 pub mod device;
 pub mod stream;
@@ -319,6 +325,7 @@ mod tests {
     #[test]
     fn test_sound_server() {
         const SOCKET_PATH: &str = "vsound.socket";
+        crate::init_logger();
 
         let config = SoundConfig::new(SOCKET_PATH.to_string(), false, BackendType::Null);
 
@@ -341,6 +348,7 @@ mod tests {
 
     #[test]
     fn test_control_message_kind_try_from() {
+        crate::init_logger();
         assert_eq!(
             ControlMessageKind::try_from(<u32 as Into<Le32>>::into(VIRTIO_SND_R_JACK_INFO)),
             Ok(ControlMessageKind::JackInfo)
@@ -361,6 +369,7 @@ mod tests {
 
     #[test]
     fn test_control_message_kind_try_from_invalid() {
+        crate::init_logger();
         // Test an invalid value that should result in an InvalidControlMessage error
         let invalid_value: u32 = 0x1101;
         assert_eq!(
@@ -371,6 +380,7 @@ mod tests {
 
     #[test]
     fn test_try_from_valid_output() {
+        crate::init_logger();
         let val = virtio_sound::VIRTIO_SND_D_OUTPUT;
         assert_eq!(Direction::try_from(val).unwrap(), Direction::Output);
 
@@ -383,6 +393,7 @@ mod tests {
 
     #[test]
     fn test_display() {
+        crate::init_logger();
         let error = InvalidControlMessage(42);
         let formatted_error = format!("{}", error);
         assert_eq!(formatted_error, "Invalid control message code 42");
@@ -390,6 +401,7 @@ mod tests {
 
     #[test]
     fn test_into_error() {
+        crate::init_logger();
         let error = InvalidControlMessage(42);
         let _error: Error = error.into();
 

staging/vhost-device-sound/src/main.rs

@@ -53,8 +53,14 @@ mod tests {
         }
     }
 
+    fn init_logger() {
+        std::env::set_var("RUST_LOG", "trace");
+        let _ = env_logger::builder().is_test(true).try_init();
+    }
+
     #[test]
     fn test_sound_config_setup() {
+        init_logger();
         let args = SoundArgs::from_args("/tmp/vhost-sound.socket");
 
         let config = SoundConfig::try_from(args);