Set conditional default backend

.gitignore

@@ -32,4 +32,5 @@ tags
 
 *.rustfmt
 
-.idea
+.idea
+.vscode

src/config.rs

@@ -18,6 +18,13 @@ use url::Url;
 
 const CONFIG_FILE_NAME: &str = "spotifyd.conf";
 
+#[cfg(not(any(
+    feature = "pulseaudio_backend",
+    feature = "portaudio_backend",
+    feature = "alsa_backend",
+    feature = "rodio_backend"
+)))]
+compile_error!("At least one of the backend features is required!");
 static BACKEND_VALUES: &[&str] = &[
     #[cfg(feature = "alsa_backend")]
     "alsa",
@@ -39,6 +46,10 @@ pub enum Backend {
     Rodio,
 }
 
+fn default_backend() -> Backend {
+    return Backend::from_str(BACKEND_VALUES.first().unwrap()).unwrap();
+}
+
 impl FromStr for Backend {
     type Err = ParseError;
 
@@ -649,7 +660,7 @@ pub(crate) fn get_internal_config(config: CliConfig) -> SpotifydConfig {
     let backend = config
         .shared_config
         .backend
-        .unwrap_or(Backend::Alsa)
+        .unwrap_or_else(default_backend)
         .to_string();
 
     let volume_controller = config
@@ -812,4 +823,12 @@ mod tests {
         spotifyd_section.username = Some("testUserName".to_string());
         assert_eq!(merged_config, spotifyd_section);
     }
+    #[test]
+    fn test_default_backend() {
+        let spotifyd_config = get_internal_config(CliConfig::default());
+        assert_eq!(
+            spotifyd_config.backend.unwrap(),
+            default_backend().to_string()
+        );
+    }
 }

src/utils.rs

@@ -48,7 +48,7 @@ fn get_shell_ffi() -> Option<String> {
 
     let username = whoami::username();
     let output = Command::new("dscl")
-        .args(&[".", "-read", &format!("/Users/{}", username), "UserShell"])
+        .args([".", "-read", &format!("/Users/{}", username), "UserShell"])
         .output()
         .ok()?;