fix: resolve unit test failures and improve config file handling

Author: inureyes

src/config.rs

@@ -231,7 +231,7 @@ impl Config {
     }
 
     /// Load configuration with priority order:
-    /// 1. Explicit --config path (if different from default)
+    /// 1. Explicit --config path (if exists and different from default)
     /// 2. Backend.AI environment variables
     /// 3. Current directory config.yaml
     /// 4. XDG config directory ($XDG_CONFIG_HOME/bssh/config.yaml or ~/.config/bssh/config.yaml)
@@ -244,18 +244,19 @@ impl Config {
         // Check if user explicitly specified a config file (different from default)
         let is_custom_config = expanded_cli_path != expanded_default_path;
 
-        if is_custom_config {
-            // User explicitly specified a config file - use it with highest priority
+        if is_custom_config && expanded_cli_path.exists() {
+            // User explicitly specified a config file and it exists - use it with highest priority
             tracing::debug!(
                 "Using explicitly specified config file: {:?}",
                 expanded_cli_path
             );
-            if expanded_cli_path.exists() {
-                return Self::load(&expanded_cli_path).await;
-            } else {
-                // If the user specified a file that doesn't exist, return an error
-                anyhow::bail!("Config file not found: {:?}", expanded_cli_path);
-            }
+            return Self::load(&expanded_cli_path).await;
+        } else if is_custom_config {
+            // Custom config specified but doesn't exist - log and continue
+            tracing::debug!(
+                "Custom config file not found, continuing with other sources: {:?}",
+                expanded_cli_path
+            );
         }
 
         // Try Backend.AI environment first

src/main.rs

@@ -66,6 +66,28 @@ async fn main() -> Result<()> {
     // Initialize logging
     init_logging(cli.verbose);
 
+    // Check if user explicitly specified --config option
+    let args: Vec<String> = std::env::args().collect();
+    let has_explicit_config = args.iter().any(|arg| arg == "--config");
+
+    // If user explicitly specified --config, ensure the file exists
+    if has_explicit_config {
+        let expanded_path = if cli.config.starts_with("~") {
+            let path_str = cli.config.to_string_lossy();
+            if let Ok(home) = std::env::var("HOME") {
+                PathBuf::from(path_str.replacen("~", &home, 1))
+            } else {
+                cli.config.clone()
+            }
+        } else {
+            cli.config.clone()
+        };
+
+        if !expanded_path.exists() {
+            anyhow::bail!("Config file not found: {:?}", expanded_path);
+        }
+    }
+
     // Load configuration with priority
     let config = Config::load_with_priority(&cli.config).await?;