refactor: implement event handling

src/events.rs

@@ -0,0 +1,38 @@
+use crossterm::event::{self, Event, KeyCode, KeyModifiers};
+use crate::msg::Message;
+
+pub fn handle_event(event: Event) -> Option<Message> {
+  if let Event::Key(key) = event
+    && key.kind == event::KeyEventKind::Press
+  {
+    match key.code {
+      KeyCode::Char('q') | KeyCode::Char('Q') => Some(Message::Quit),
+      KeyCode::Char('c') if key.modifiers.contains(KeyModifiers::CONTROL) => Some(Message::Quit),
+      KeyCode::Char(' ') => Some(Message::ToggleRunning),
+      KeyCode::Char('s') | KeyCode::Char('S') => Some(Message::ToggleMode),
+      KeyCode::Char('r') | KeyCode::Char('R') => Some(Message::Reset),
+      KeyCode::Char('?') => Some(Message::ToggleHelp),
+      _ => None,
+    }
+  } else {
+    None
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+  use crossterm::event::KeyEvent;
+
+  #[test]
+  fn handle_event_when_called_maps_key_presses_to_messages() {
+    let key_event = Event::Key(KeyEvent::new(KeyCode::Char(' '), KeyModifiers::NONE));
+    assert_eq!(handle_event(key_event), Some(Message::ToggleRunning));
+
+    let key_event_q = Event::Key(KeyEvent::new(KeyCode::Char('q'), KeyModifiers::NONE));
+    assert_eq!(handle_event(key_event_q), Some(Message::Quit));
+
+    let key_event_unknown = Event::Key(KeyEvent::new(KeyCode::Char('z'), KeyModifiers::NONE));
+    assert_eq!(handle_event(key_event_unknown), None);
+  }
+}