add tests

src/app.rs

@@ -495,3 +495,22 @@ impl App {
         Ok(EventState::NotConsumed)
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::{App, Config, EventState, Key};
+
+    fn test_extend_or_shorten_widget_width() {
+        let mut app = App::new(Config::default());
+        assert_eq!(
+            app.extend_or_shorten_widget_width(Key::Char('<')).unwrap(),
+            EventState::Consumed
+        );
+        aasert_eq!(app.left_chunk_percentage, )
+
+        assert_eq!(
+            app.extend_or_shorten_widget_width(Key::Char('>')).unwrap(),
+            EventState::Consumed
+        );
+    }
+}

src/components/mod.rs

@@ -37,7 +37,7 @@ use std::convert::TryInto;
 use tui::{backend::Backend, layout::Rect, Frame};
 use unicode_width::UnicodeWidthChar;
 
-#[derive(PartialEq)]
+#[derive(PartialEq, Debug)]
 pub enum EventState {
     Consumed,
     NotConsumed,