feat(cli): add "--no-clear-screen" flag (#13454)

This commit adds "--no-clear-screen" flag which can be used
with "--watch" flag to disable clearing of terminal screen on
each file change.

1 files changed, 33 insertions, 11 deletions

diff --git a/cli/file_watcher.rs b/cli/file_watcher.rs
index 87531bb77..fd7d4e1a1 100644
--- a/cli/file_watcher.rs
+++ b/cli/file_watcher.rs
@@ -91,18 +91,19 @@ where
         paths_to_watch,
         result,
       } => {
-        // Clear screen first
-        eprint!("{}", CLEAR_SCREEN);
-        info!(
-          "{} File change detected! Restarting!",
-          colors::intense_blue("Watcher"),
-        );
         return (paths_to_watch, result);
       }
     }
   }
 }
 
+pub struct PrintConfig {
+  /// printing watcher status to terminal.
+  pub job_name: String,
+  /// determine whether to clear the terminal screen
+  pub clear_screen: bool,
+}
+
 /// Creates a file watcher, which will call `resolver` with every file change.
 ///
 /// - `resolver` is used for resolving file paths to be watched at every restarting
@@ -113,12 +114,10 @@ where
 /// - `operation` is the actual operation we want to run every time the watcher detects file
 /// changes. For example, in the case where we would like to bundle, then `operation` would
 /// have the logic for it like bundling the code.
-///
-/// - `job_name` is just used for printing watcher status to terminal.
 pub async fn watch_func<R, O, T, F1, F2>(
   mut resolver: R,
   mut operation: O,
-  job_name: &str,
+  print_config: PrintConfig,
 ) -> Result<(), AnyError>
 where
   R: FnMut(Option<Vec<PathBuf>>) -> F1,
@@ -128,11 +127,26 @@ where
 {
   let (sender, mut receiver) = DebouncedReceiver::new_with_sender();
 
+  let PrintConfig {
+    job_name,
+    clear_screen,
+  } = print_config;
+
   // Store previous data. If module resolution fails at some point, the watcher will try to
   // continue watching files using these data.
   let mut paths_to_watch;
   let mut resolution_result;
 
+  let print_after_restart = || {
+    if clear_screen {
+      eprint!("{}", CLEAR_SCREEN);
+    }
+    info!(
+      "{} File change detected! Restarting!",
+      colors::intense_blue("Watcher"),
+    );
+  };
+
   match resolver(None).await {
     ResolutionResult::Ignore => {
       // The only situation where it makes sense to ignore the initial 'change'
@@ -149,6 +163,8 @@ where
       let (paths, result) = next_restart(&mut resolver, &mut receiver).await;
       paths_to_watch = paths;
       resolution_result = result;
+
+      print_after_restart();
     }
     ResolutionResult::Restart {
       paths_to_watch: paths,
@@ -159,8 +175,10 @@ where
     }
   };
 
-  // Clear screen first
-  eprint!("{}", CLEAR_SCREEN);
+  if clear_screen {
+    eprint!("{}", CLEAR_SCREEN);
+  }
+
   info!("{} {} started.", colors::intense_blue("Watcher"), job_name,);
 
   loop {
@@ -175,6 +193,8 @@ where
               paths_to_watch = paths;
             }
             resolution_result = result;
+
+            print_after_restart();
             continue;
           },
           _ = fut => {},
@@ -202,6 +222,8 @@ where
     }
     resolution_result = result;
 
+    print_after_restart();
+
     drop(watcher);
   }
 }