Add clear screen option when watching for changes before starting

the build clear the screen if enabled.

src/cmd/serve.rs

@@ -194,6 +194,7 @@ impl Serve {
                 },
                 poll: self.watch.poll.then_some(self.watch.poll_interval.0),
                 enable_cooldown: self.watch.enable_cooldown,
+                clear_screen: self.watch.clear_screen,
                 no_error_reporting: cfg.serve.no_error_reporting,
             },
             // This will be the effective value for `serve.open` during runtime.

src/cmd/watch.rs

@@ -32,6 +32,9 @@ pub struct Watch {
     /// Allow enabling a cooldown, discarding all change events during the build
     #[arg(long, env = "TRUNK_WATCH_ENABLE_COOLDOWN")]
     pub enable_cooldown: bool,
+    /// Clear the screen before each run
+    #[arg(short, long = "clear", env = "TRUNK_WATCH_CLEAR")]
+    pub clear_screen: bool,
 
     // NOTE: flattened structures come last
     #[command(flatten)]
@@ -47,6 +50,7 @@ impl Watch {
             poll: _,
             poll_interval: _,
             enable_cooldown: _,
+            clear_screen: _,
             build,
         } = self;
 
@@ -70,6 +74,7 @@ impl Watch {
             },
             poll: self.poll.then_some(self.poll_interval.0),
             enable_cooldown: self.enable_cooldown,
+            clear_screen: self.clear_screen,
             // in watch mode we can't report errors
             no_error_reporting: false,
         })

src/config/models/test.rs

@@ -41,6 +41,7 @@ async fn err_bad_trunk_toml_watch_path() {
         },
         poll: None,
         enable_cooldown: false,
+        clear_screen: false,
         no_error_reporting: false,
     })
     .await
@@ -68,6 +69,7 @@ async fn err_bad_trunk_toml_watch_ignore() {
         },
         poll: None,
         enable_cooldown: false,
+        clear_screen: false,
         no_error_reporting: false,
     })
     .await

src/config/rt/watch.rs

@@ -18,6 +18,8 @@ pub struct RtcWatch {
     pub poll: Option<Duration>,
     /// Allow enabling a cooldown
     pub enable_cooldown: bool,
+    /// Clear the screen before each run
+    pub clear_screen: bool,
     /// No error reporting.
     pub no_error_reporting: bool,
 }
@@ -37,6 +39,8 @@ pub struct WatchOptions {
     pub poll: Option<Duration>,
     /// Allow enabling a cooldown
     pub enable_cooldown: bool,
+    /// Clear the screen before each run
+    pub clear_screen: bool,
     /// No error reporting.
     pub no_error_reporting: bool,
 }
@@ -48,6 +52,7 @@ impl RtcWatch {
             build: build_opts,
             poll,
             enable_cooldown,
+            clear_screen,
             no_error_reporting,
         } = opts;
 
@@ -98,6 +103,7 @@ impl RtcWatch {
             ignored_paths,
             poll,
             enable_cooldown,
+            clear_screen,
             no_error_reporting,
         })
     }

src/watch.rs

@@ -91,6 +91,8 @@ pub struct WatchSystem {
     last_change: Instant,
     /// The cooldown for the watcher. [`None`] disables the cooldown.
     watcher_cooldown: Option<Duration>,
+    /// Clear the screen before each run
+    clear_screen: bool,
     /// Don't send build errors to the frontend.
     no_error_reporting: bool,
 }
@@ -136,6 +138,7 @@ impl WatchSystem {
             last_build_finished: Instant::now(),
             last_change: Instant::now(),
             watcher_cooldown,
+            clear_screen: cfg.clear_screen,
             no_error_reporting: cfg.no_error_reporting,
         })
     }
@@ -228,6 +231,16 @@ impl WatchSystem {
             }
         }
 
+        if self.clear_screen {
+            // This first message will not be seen if the clear screen worked.
+            tracing::trace!("Clear screen is enabled, clearing the screen");
+            let term = console::Term::stdout();
+            if let Err(err) = term.clear_screen() {
+                tracing::error!("Unable to clear the screen due to error: #{err}");
+            } else {
+                tracing::trace!("Clear screen is enabled, cleared the screen");
+            }
+        }
         self.spawn_build().await;
     }