Add CliAction::config_dir accessor

Collapses the verbose nine-variant match in main.rs into a single
call. Putting the projection on the type keeps the variant list in
one place, so adding a future variant only updates args.rs.

Author: psi4j

src/args.rs

@@ -129,6 +129,24 @@ pub enum CliAction {
     },
 }
 
+impl CliAction {
+    /// Returns the custom config directory carried by this action, if any.
+    pub fn config_dir(&self) -> Option<&str> {
+        match self {
+            Self::Run { config_dir, .. }
+            | Self::TestCommand { config_dir, .. }
+            | Self::GeoCommand { config_dir, .. }
+            | Self::PresetCommand { config_dir, .. }
+            | Self::SetCommand { config_dir, .. }
+            | Self::GetCommand { config_dir, .. }
+            | Self::StopCommand { config_dir, .. }
+            | Self::RestartCommand { config_dir, .. }
+            | Self::Simulate { config_dir, .. } => config_dir.as_deref(),
+            _ => None,
+        }
+    }
+}
+
 /// Result of parsing command-line arguments.
 pub struct ParsedArgs {
     pub action: CliAction,

src/main.rs

@@ -17,21 +17,8 @@ use sunsetr::{
 fn main() -> Result<()> {
     let parsed_args = ParsedArgs::from_env();
 
-    let config_dir = match &parsed_args.action {
-        CliAction::Run { config_dir, .. }
-        | CliAction::TestCommand { config_dir, .. }
-        | CliAction::GeoCommand { config_dir, .. }
-        | CliAction::PresetCommand { config_dir, .. }
-        | CliAction::SetCommand { config_dir, .. }
-        | CliAction::GetCommand { config_dir, .. }
-        | CliAction::StopCommand { config_dir, .. }
-        | CliAction::RestartCommand { config_dir, .. }
-        | CliAction::Simulate { config_dir, .. } => config_dir.clone(),
-        _ => None,
-    };
-
-    if let Some(dir) = config_dir
-        && let Err(e) = config::set_config_dir(Some(dir))
+    if let Some(dir) = parsed_args.action.config_dir()
+        && let Err(e) = config::set_config_dir(Some(dir.to_string()))
     {
         log_error_exit!("{}", e);
     }