feat(watch): log which file changed on HMR or watch change (#25801)

Closes #25504

cli/tools/bench/mod.rs

@@ -486,6 +486,7 @@ pub async fn run_benchmarks_with_watch(
     ),
     move |flags, watcher_communicator, changed_paths| {
       let bench_flags = bench_flags.clone();
+      watcher_communicator.show_path_changed(changed_paths.clone());
       Ok(async move {
         let factory = CliFactory::from_flags_for_watcher(
           flags,

cli/tools/fmt.rs

@@ -83,6 +83,7 @@ pub async fn format(
       file_watcher::PrintConfig::new("Fmt", !watch_flags.no_clear_screen),
       move |flags, watcher_communicator, changed_paths| {
         let fmt_flags = fmt_flags.clone();
+        watcher_communicator.show_path_changed(changed_paths.clone());
         Ok(async move {
           let factory = CliFactory::from_flags(flags);
           let cli_options = factory.cli_options()?;

cli/tools/lint/mod.rs

@@ -80,6 +80,7 @@ pub async fn lint(
       file_watcher::PrintConfig::new("Lint", !watch_flags.no_clear_screen),
       move |flags, watcher_communicator, changed_paths| {
         let lint_flags = lint_flags.clone();
+        watcher_communicator.show_path_changed(changed_paths.clone());
         Ok(async move {
           let factory = CliFactory::from_flags(flags);
           let cli_options = factory.cli_options()?;

cli/tools/run/mod.rs

@@ -124,7 +124,8 @@ async fn run_with_watch(
       !watch_flags.no_clear_screen,
     ),
     WatcherRestartMode::Automatic,
-    move |flags, watcher_communicator, _changed_paths| {
+    move |flags, watcher_communicator, changed_paths| {
+      watcher_communicator.show_path_changed(changed_paths.clone());
       Ok(async move {
         let factory = CliFactory::from_flags_for_watcher(
           flags,

cli/tools/serve.rs

@@ -151,7 +151,8 @@ async fn serve_with_watch(
       !watch_flags.no_clear_screen,
     ),
     WatcherRestartMode::Automatic,
-    move |flags, watcher_communicator, _changed_paths| {
+    move |flags, watcher_communicator, changed_paths| {
+      watcher_communicator.show_path_changed(changed_paths.clone());
       Ok(async move {
         let factory = CliFactory::from_flags_for_watcher(
           flags,

cli/tools/test/mod.rs

@@ -1661,6 +1661,7 @@ pub async fn run_tests_with_watch(
     ),
     move |flags, watcher_communicator, changed_paths| {
       let test_flags = test_flags.clone();
+      watcher_communicator.show_path_changed(changed_paths.clone());
       Ok(async move {
         let factory = CliFactory::from_flags_for_watcher(
           flags,

cli/util/file_watcher.rs

@@ -127,19 +127,12 @@ impl PrintConfig {
   }
 }
 
-fn create_print_after_restart_fn(
+fn create_print_after_restart_fn(clear_screen: bool) -> impl Fn() {
-  banner: &'static str,
-  clear_screen: bool,
-) -> impl Fn() {
   move || {
     #[allow(clippy::print_stderr)]
     if clear_screen && std::io::stderr().is_terminal() {
       eprint!("{}", CLEAR_SCREEN);
     }
-    info!(
-      "{} File change detected! Restarting!",
-      colors::intense_blue(banner),
-    );
   }
 }
 
@@ -187,7 +180,15 @@ impl WatcherCommunicator {
   }
 
   pub fn print(&self, msg: String) {
-    log::info!("{} {}", self.banner, msg);
+    log::info!("{} {}", self.banner, colors::gray(msg));
+  }
+
+  pub fn show_path_changed(&self, changed_paths: Option<Vec<PathBuf>>) {
+    if let Some(paths) = changed_paths {
+      self.print(
+        format!("Restarting! File change detected: {:?}", paths[0]).to_string(),
+      )
+    }
   }
 }
 
@@ -263,7 +264,7 @@ where
     clear_screen,
   } = print_config;
 
-  let print_after_restart = create_print_after_restart_fn(banner, clear_screen);
+  let print_after_restart = create_print_after_restart_fn(clear_screen);
   let watcher_communicator = Arc::new(WatcherCommunicator {
     paths_to_watch_tx: paths_to_watch_tx.clone(),
     changed_paths_rx: changed_paths_rx.resubscribe(),

tests/integration/watcher_tests.rs

@@ -55,7 +55,7 @@ where
   let mut str = String::new();
   while let Some(t) = next_line(stderr_lines).await {
     let t = util::strip_ansi_codes(&t);
-    if t.starts_with("Watcher File change detected") {
+    if t.starts_with("Watcher Restarting! File change detected") {
       continue;
     }
     if t.starts_with("Watcher") {