Only render when needed

src/app_state.rs

@@ -24,10 +24,10 @@ const STATE_FILE_NAME: &str = ".rustlings-state.txt";
 pub enum ExercisesProgress {
     // All exercises are done.
     AllDone,
-    // The current exercise failed and is still pending.
-    CurrentPending,
     // A new exercise is now pending.
     NewPending,
+    // The current exercise is still pending.
+    CurrentPending,
 }
 
 pub enum StateFileStatus {

src/run.rs

@@ -45,7 +45,7 @@ pub fn run(app_state: &mut AppState) -> Result<()> {
     }
 
     match app_state.done_current_exercise(&mut stdout)? {
-        ExercisesProgress::CurrentPending | ExercisesProgress::NewPending => {
+        ExercisesProgress::NewPending | ExercisesProgress::CurrentPending => {
             stdout.write_all(b"Next exercise: ")?;
             app_state
                 .current_exercise()

src/watch.rs

@@ -83,13 +83,11 @@ fn run_watch(
         match event {
             WatchEvent::Input(InputEvent::Next) => match watch_state.next_exercise(&mut stdout)? {
                 ExercisesProgress::AllDone => break,
-                ExercisesProgress::CurrentPending => watch_state.render(&mut stdout)?,
                 ExercisesProgress::NewPending => watch_state.run_current_exercise(&mut stdout)?,
+                ExercisesProgress::CurrentPending => (),
             },
             WatchEvent::Input(InputEvent::Hint) => watch_state.show_hint(&mut stdout)?,
-            WatchEvent::Input(InputEvent::List) => {
-                return Ok(WatchExit::List);
-            }
+            WatchEvent::Input(InputEvent::List) => return Ok(WatchExit::List),
             WatchEvent::Input(InputEvent::Quit) => {
                 stdout.write_all(QUIT_MSG)?;
                 break;
@@ -99,9 +97,7 @@ fn run_watch(
                 watch_state.handle_file_change(exercise_ind, &mut stdout)?;
             }
             WatchEvent::TerminalResize => watch_state.render(&mut stdout)?,
-            WatchEvent::NotifyErr(e) => {
-                return Err(Error::from(e).context(NOTIFY_ERR));
-            }
+            WatchEvent::NotifyErr(e) => return Err(Error::from(e).context(NOTIFY_ERR)),
             WatchEvent::TerminalEventErr(e) => {
                 return Err(Error::from(e).context("Terminal event listener failed"));
             }

src/watch/state.rs

@@ -195,7 +195,11 @@ impl<'a> WatchState<'a> {
     }
 
     pub fn show_hint(&mut self, stdout: &mut StdoutLock) -> io::Result<()> {
-        self.show_hint = true;
-        self.render(stdout)
+        if !self.show_hint {
+            self.show_hint = true;
+            self.render(stdout)?;
+        }
+
+        Ok(())
     }
 }