diff --git a/src/config.rs b/src/config.rs
index a8a83ab..fb488ea 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -192,4 +192,53 @@ mod tests {
             "expected field path in error, got: {message}"
         );
     }
+
+    #[test]
+    fn join_relative_keeps_relative_paths() {
+        assert_eq!(
+            join_relative(Path::new("/base"), Path::new("sub/x.py")),
+            PathBuf::from("/base/sub/x.py")
+        );
+    }
+
+    #[test]
+    fn join_relative_strips_leading_slash() {
+        assert_eq!(
+            join_relative(Path::new("/base"), Path::new("/sub/x.py")),
+            PathBuf::from("/base/sub/x.py")
+        );
+    }
+
+    #[test]
+    fn absolute_entry_points_resolve_relative_to_dir() {
+        // A leading slash on an entry point is treated as relative to `dir`,
+        // not as an absolute path.
+        let json = r#"{
+            "deployments_base": "/apps",
+            "default_venv_name": ".venv",
+            "default_gui_file": "src/gui.py",
+            "default_server_file": "src/server.py",
+            "map": { "x10sa": { "dir": "d", "gui_file": "/abs/gui.py" } }
+        }"#;
+
+        let config = load_config(json).unwrap();
+        assert_eq!(
+            config.entries["x10sa"].gui_file,
+            PathBuf::from("/apps/d/abs/gui.py")
+        );
+    }
+
+    #[test]
+    fn custom_venv_overrides_default() {
+        let config = load_config(SAMPLE).unwrap();
+        // x10sa sets "venv": "pxii"; x06da falls back to ".venv".
+        assert_eq!(
+            config.entries["x10sa"].python,
+            PathBuf::from("/apps/aaredaq-pxii/pxii/bin/python")
+        );
+        assert_eq!(
+            config.entries["x06da"].python,
+            PathBuf::from("/apps/aaredaq-pxiii/.venv/bin/python")
+        );
+    }
 }
diff --git a/src/tui/custom.rs b/src/tui/custom.rs
index 29d35b3..c50e8f2 100644
--- a/src/tui/custom.rs
+++ b/src/tui/custom.rs
@@ -155,3 +155,54 @@ fn dir_list<'a>(title: &'a str, items: &'a [String], focused: bool) -> List<'a>
         .highlight_style(Style::default().add_modifier(Modifier::BOLD | Modifier::REVERSED))
         .highlight_symbol("> ")
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn items(n: usize) -> Vec<String> {
+        (0..n).map(|i| i.to_string()).collect()
+    }
+
+    #[test]
+    fn initial_state_selects_first_when_nonempty() {
+        assert_eq!(initial_state(&items(3)).selected(), Some(0));
+    }
+
+    #[test]
+    fn initial_state_selects_nothing_when_empty() {
+        assert_eq!(initial_state(&items(0)).selected(), None);
+    }
+
+    #[test]
+    fn select_relative_moves_within_bounds() {
+        let items = items(3);
+        let mut state = initial_state(&items);
+        select_relative(&items, &mut state, 1);
+        assert_eq!(state.selected(), Some(1));
+    }
+
+    #[test]
+    fn select_relative_wraps_forward_past_end() {
+        let items = items(3);
+        let mut state = ListState::default();
+        state.select(Some(2));
+        select_relative(&items, &mut state, 1);
+        assert_eq!(state.selected(), Some(0));
+    }
+
+    #[test]
+    fn select_relative_wraps_backward_past_start() {
+        let items = items(3);
+        let mut state = initial_state(&items);
+        select_relative(&items, &mut state, -1);
+        assert_eq!(state.selected(), Some(2));
+    }
+
+    #[test]
+    fn select_relative_on_empty_is_noop() {
+        let mut state = ListState::default();
+        select_relative(&items(0), &mut state, 1);
+        assert_eq!(state.selected(), None);
+    }
+}