updates

libmarlin/src/config_tests.rs

@@ -0,0 +1,22 @@
+// libmarlin/src/config_tests.rs
+
+use super::config::Config;
+use std::env;
+use tempfile::tempdir;
+
+#[test]
+fn load_env_override() {
+    let tmp = tempdir().unwrap();
+    let db = tmp.path().join("custom.db");
+    env::set_var("MARLIN_DB_PATH", &db);
+    let cfg = Config::load().unwrap();
+    assert_eq!(cfg.db_path, db);
+    env::remove_var("MARLIN_DB_PATH");
+}
+
+#[test]
+fn load_xdg_or_fallback() {
+    // since XDG_DATA_HOME will normally be present, just test it doesn't error
+    let cfg = Config::load().unwrap();
+    assert!(cfg.db_path.to_string_lossy().ends_with(".db"));
+}