test: Add unit tests for config merging and project name sanitization (#6)

* test: Add unit tests for config merging and project name sanitization

* Update src/utils/project.rs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* test: Update assertion for follow_symlinks in scanner configuration

* test: Fix typo in test function name for project info retrieval

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

src/utils/config.rs

@@ -282,3 +282,42 @@ fn merge_configs(mut default: Config, user: Config) -> Config {
 
     default
 }
+
+#[test]
+fn merge_configs_dedupes_and_keeps_order() {
+  let mut default_cfg = Config::default();
+  default_cfg.scanner.excluded_extensions = vec!["rs".into(), "toml".into()];
+
+  let mut user_cfg = Config::default();
+  user_cfg.scanner.excluded_extensions = vec!["jpg".into(), "rs".into()];
+
+  let merged = merge_configs(default_cfg, user_cfg);
+  
+  assert_eq!(merged.scanner.excluded_extensions, vec!["jpg", "rs", "toml"]);
+}
+
+#[test]
+fn load_creates_example_and_reads_user_overrides() {
+  let cfg_dir = tempfile::tempdir().unwrap();
+  let cfg_path = cfg_dir.path();
+  
+  let user_toml = r#"
+        [scanner]
+        one_file_system = true
+        excluded_extensions = ["foo"]
+
+        [output]
+        quiet = true
+    "#;
+  fs::write(cfg_path.join("nyx.local"), user_toml).unwrap();
+
+  let cfg = Config::load(cfg_path).expect("Config::load should succeed");
+
+  assert!(cfg_path.join("nyx.conf").is_file());
+  
+  assert!(cfg.scanner.one_file_system);
+  assert!(cfg.output.quiet);
+  assert!(cfg.scanner.excluded_extensions.contains(&"foo".to_string()));
+
+  assert!(!cfg.scanner.follow_symlinks);
+}

src/utils/ext.rs

@@ -12,3 +12,19 @@ pub fn lowercase_ext(path: &std::path::Path) -> Option<&'static str> {
         _ => None,
     })
 }
+
+#[test]
+fn lowercase_ext_recognises_known_extensions() {
+  let cases = [
+    ("file.rs",  Some("rs")),
+    ("FILE.RS",  Some("rs")),
+    ("main.cpp", Some("cpp")),
+    ("script.PY",Some("py")),
+    ("index.tsx",Some("ts")),
+    ("style.css",None),      // unsupported
+  ];
+
+  for (file, expected) in cases {
+    assert_eq!(lowercase_ext(std::path::Path::new(file)), expected, "case: {file}");
+  }
+}

src/utils/mod.rs

@@ -4,5 +4,4 @@ pub mod project;
 pub(crate) mod query_cache;
 
 pub use config::Config;
-// Re-export commonly used functions for convenience
 pub use project::get_project_info;

src/utils/project.rs

@@ -28,3 +28,36 @@ pub fn sanitize_project_name(name: &str) -> String {
         .collect::<Vec<_>>()
         .join("_")
 }
+
+#[test]
+fn sanitize_project_name_is_idempotent_and_lossless_enough() {
+  let samples = [
+    ("My Project",      "my_project"),
+    ("Hello-World",     "hello-world"),
+    ("mixed_case",      "mixed_case"),
+    ("tabs\tspaces\n",  "tabs_spaces"),
+    ("   multiple   ",  "multiple"),
+    ("weird@$*chars",   "weird_chars"),
+  ];
+
+  for (input, expected) in samples {
+    assert_eq!(sanitize_project_name(input), expected, "input: {}", input);
+    assert_eq!(sanitize_project_name(expected), expected);
+  }
+}
+
+#[test]
+fn get_project_info_uses_sanitized_name_in_sqlite_path() {
+  let tmp = tempfile::tempdir().unwrap();
+  let root = tmp.path();
+  
+  let project_dir = root.join("Example Project");
+  std::fs::create_dir(&project_dir).unwrap();
+
+  let (project_name, db_path) =
+    get_project_info(&project_dir, root).expect("should detect project");
+
+  assert_eq!(project_name, "Example Project");
+  assert_eq!(db_path, root.join("example_project.sqlite"));
+}
+