fix: watch dynamic imports in --watch (#14775)

Fix dynamic imports being watched in the watcher when using `--watch`.

cli/file_watcher.rs

@@ -19,6 +19,7 @@ use std::sync::Arc;
 use std::time::Duration;
 use tokio::select;
 use tokio::sync::mpsc;
+use tokio::sync::mpsc::UnboundedReceiver;
 use tokio::time::sleep;
 
 const CLEAR_SCREEN: &str = "\x1B[2J\x1B[1;1H";
@@ -114,6 +115,18 @@ pub struct PrintConfig {
   pub clear_screen: bool,
 }
 
+fn create_print_after_restart_fn(clear_screen: bool) -> impl Fn() {
+  move || {
+    if clear_screen {
+      eprint!("{}", CLEAR_SCREEN);
+    }
+    info!(
+      "{} File change detected! Restarting!",
+      colors::intense_blue("Watcher"),
+    );
+  }
+}
+
 /// 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
@@ -147,15 +160,7 @@ where
   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"),
-    );
-  };
+  let print_after_restart = create_print_after_restart_fn(clear_screen);
 
   match resolver(None).await {
     ResolutionResult::Ignore => {
@@ -188,7 +193,8 @@ where
   info!("{} {} started.", colors::intense_blue("Watcher"), job_name,);
 
   loop {
-    let watcher = new_watcher(&paths_to_watch, sender.clone())?;
+    let mut watcher = new_watcher(sender.clone())?;
+    add_paths_to_watcher(&mut watcher, &paths_to_watch);
 
     match resolution_result {
       Ok(operation_arg) => {
@@ -234,8 +240,99 @@ where
   }
 }
 
+/// Creates a file watcher.
+///
+/// - `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.
+pub async fn watch_func2<T: Clone, O, F>(
+  mut paths_to_watch_receiver: mpsc::UnboundedReceiver<Vec<PathBuf>>,
+  mut operation: O,
+  operation_args: T,
+  print_config: PrintConfig,
+) -> Result<(), AnyError>
+where
+  O: FnMut(T) -> F,
+  F: Future<Output = Result<(), AnyError>>,
+{
+  let (watcher_sender, mut watcher_receiver) =
+    DebouncedReceiver::new_with_sender();
+
+  let PrintConfig {
+    job_name,
+    clear_screen,
+  } = print_config;
+
+  let print_after_restart = create_print_after_restart_fn(clear_screen);
+
+  info!("{} {} started.", colors::intense_blue("Watcher"), job_name,);
+
+  fn consume_paths_to_watch(
+    watcher: &mut RecommendedWatcher,
+    receiver: &mut UnboundedReceiver<Vec<PathBuf>>,
+  ) {
+    loop {
+      match receiver.try_recv() {
+        Ok(paths) => {
+          add_paths_to_watcher(watcher, &paths);
+        }
+        Err(e) => match e {
+          mpsc::error::TryRecvError::Empty => {
+            break;
+          }
+          // there must be at least one receiver alive
+          _ => unreachable!(),
+        },
+      }
+    }
+  }
+
+  loop {
+    let mut watcher = new_watcher(watcher_sender.clone())?;
+    consume_paths_to_watch(&mut watcher, &mut paths_to_watch_receiver);
+
+    let receiver_future = async {
+      loop {
+        let maybe_paths = paths_to_watch_receiver.recv().await;
+        add_paths_to_watcher(&mut watcher, &maybe_paths.unwrap());
+      }
+    };
+    let operation_future = error_handler(operation(operation_args.clone()));
+
+    select! {
+      _ = receiver_future => {},
+      _ = watcher_receiver.recv() => {
+        print_after_restart();
+        continue;
+      },
+      _ = operation_future => {
+        // TODO(bartlomieju): print exit code here?
+        info!(
+          "{} {} finished. Restarting on file change...",
+          colors::intense_blue("Watcher"),
+          job_name,
+        );
+        consume_paths_to_watch(&mut watcher, &mut paths_to_watch_receiver);
+      },
+    };
+
+    let receiver_future = async {
+      loop {
+        let maybe_paths = paths_to_watch_receiver.recv().await;
+        add_paths_to_watcher(&mut watcher, &maybe_paths.unwrap());
+      }
+    };
+    select! {
+      _ = receiver_future => {},
+      _ = watcher_receiver.recv() => {
+        print_after_restart();
+        continue;
+      },
+    };
+  }
+}
+
 fn new_watcher(
-  paths: &[PathBuf],
   sender: Arc<mpsc::UnboundedSender<Vec<PathBuf>>>,
 ) -> Result<RecommendedWatcher, AnyError> {
   let mut watcher: RecommendedWatcher =
@@ -257,11 +354,13 @@ fn new_watcher(
 
   watcher.configure(Config::PreciseEvents(true)).unwrap();
 
-  log::debug!("Watching paths: {:?}", paths);
-  for path in paths {
-    // Ignore any error e.g. `PathNotFound`
-    let _ = watcher.watch(path, RecursiveMode::Recursive);
-  }
-
   Ok(watcher)
 }
+
+fn add_paths_to_watcher(watcher: &mut RecommendedWatcher, paths: &[PathBuf]) {
+  // Ignore any error e.g. `PathNotFound`
+  for path in paths {
+    let _ = watcher.watch(path, RecursiveMode::Recursive);
+  }
+  log::debug!("Watching paths: {:?}", paths);
+}

cli/main.rs

@@ -995,100 +995,6 @@ async fn run_from_stdin(flags: Flags) -> Result<i32, AnyError> {
 // TODO(bartlomieju): this function is not handling `exit_code` set by the runtime
 // code properly.
 async fn run_with_watch(flags: Flags, script: String) -> Result<i32, AnyError> {
-  let flags = Arc::new(flags);
-  let resolver = |_| {
-    let script1 = script.clone();
-    let script2 = script.clone();
-    let flags = flags.clone();
-    let watch_flag = flags.watch.clone();
-    async move {
-      let main_module = resolve_url_or_path(&script1)?;
-      let ps = ProcState::build(flags).await?;
-      let mut cache = cache::FetchCacher::new(
-        ps.dir.gen_cache.clone(),
-        ps.file_fetcher.clone(),
-        Permissions::allow_all(),
-        Permissions::allow_all(),
-      );
-      let maybe_locker = lockfile::as_maybe_locker(ps.lockfile.clone());
-      let maybe_imports = if let Some(config_file) = &ps.maybe_config_file {
-        config_file.to_maybe_imports()?
-      } else {
-        None
-      };
-      let maybe_import_map_resolver =
-        ps.maybe_import_map.clone().map(ImportMapResolver::new);
-      let maybe_jsx_resolver = ps.maybe_config_file.as_ref().and_then(|cf| {
-        cf.to_maybe_jsx_import_source_module()
-          .map(|im| JsxResolver::new(im, maybe_import_map_resolver.clone()))
-      });
-      let maybe_resolver = if maybe_jsx_resolver.is_some() {
-        maybe_jsx_resolver.as_ref().map(|jr| jr.as_resolver())
-      } else {
-        maybe_import_map_resolver
-          .as_ref()
-          .map(|im| im.as_resolver())
-      };
-      let graph = deno_graph::create_graph(
-        vec![(main_module.clone(), deno_graph::ModuleKind::Esm)],
-        false,
-        maybe_imports,
-        &mut cache,
-        maybe_resolver,
-        maybe_locker,
-        None,
-        None,
-      )
-      .await;
-      let check_js = ps
-        .maybe_config_file
-        .as_ref()
-        .map(|cf| cf.get_check_js())
-        .unwrap_or(false);
-      graph_valid(
-        &graph,
-        ps.flags.type_check_mode != flags::TypeCheckMode::None,
-        check_js,
-      )?;
-
-      // Find all local files in graph
-      let mut paths_to_watch: Vec<PathBuf> = graph
-        .specifiers()
-        .iter()
-        .filter_map(|(_, r)| {
-          r.as_ref().ok().and_then(|(s, _, _)| s.to_file_path().ok())
-        })
-        .collect();
-
-      // Add the extra files listed in the watch flag
-      if let Some(watch_paths) = watch_flag {
-        paths_to_watch.extend(watch_paths);
-      }
-
-      if let Ok(Some(import_map_path)) =
-        config_file::resolve_import_map_specifier(
-          ps.flags.import_map_path.as_deref(),
-          ps.maybe_config_file.as_ref(),
-        )
-        .map(|ms| ms.and_then(|ref s| s.to_file_path().ok()))
-      {
-        paths_to_watch.push(import_map_path);
-      }
-
-      Ok((paths_to_watch, main_module, ps))
-    }
-    .map(move |result| match result {
-      Ok((paths_to_watch, module_info, ps)) => ResolutionResult::Restart {
-        paths_to_watch,
-        result: Ok((ps, module_info)),
-      },
-      Err(e) => ResolutionResult::Restart {
-        paths_to_watch: vec![PathBuf::from(script2)],
-        result: Err(e),
-      },
-    })
-  };
-
   /// The FileWatcherModuleExecutor provides module execution with safe dispatching of life-cycle events by tracking the
   /// state of any pending events and emitting accordingly on drop in the case of a future
   /// cancellation.
@@ -1144,10 +1050,19 @@ async fn run_with_watch(flags: Flags, script: String) -> Result<i32, AnyError> {
     }
   }
 
-  let operation = |(ps, main_module): (ProcState, ModuleSpecifier)| {
+  let flags = Arc::new(flags);
+  let main_module = resolve_url_or_path(&script)?;
+  let (sender, receiver) = tokio::sync::mpsc::unbounded_channel();
+
+  let operation = |(sender, main_module): (
+    tokio::sync::mpsc::UnboundedSender<Vec<PathBuf>>,
+    ModuleSpecifier,
+  )| {
     let flags = flags.clone();
     let permissions = Permissions::from_options(&flags.permissions_options());
     async move {
+      let ps = ProcState::build_for_file_watcher(flags.clone(), sender.clone())
+        .await?;
       // We make use an module executor guard to ensure that unload is always fired when an
       // operation is called.
       let mut executor = FileWatcherModuleExecutor::new(
@@ -1167,15 +1082,17 @@ async fn run_with_watch(flags: Flags, script: String) -> Result<i32, AnyError> {
     }
   };
 
-  file_watcher::watch_func(
-    resolver,
+  file_watcher::watch_func2(
+    receiver,
     operation,
+    (sender, main_module),
     file_watcher::PrintConfig {
       job_name: "Process".to_string(),
       clear_screen: !flags.no_clear_screen,
     },
   )
   .await?;
+
   Ok(0)
 }
 

cli/proc_state.rs

@@ -4,6 +4,7 @@ use crate::cache;
 use crate::colors;
 use crate::compat;
 use crate::compat::NodeEsmResolver;
+use crate::config_file;
 use crate::config_file::ConfigFile;
 use crate::config_file::MaybeImportsResult;
 use crate::deno_dir;
@@ -56,6 +57,7 @@ use log::warn;
 use std::collections::HashSet;
 use std::env;
 use std::ops::Deref;
+use std::path::PathBuf;
 use std::sync::Arc;
 
 /// This structure represents state of single "deno" program.
@@ -81,6 +83,7 @@ pub struct Inner {
   pub shared_array_buffer_store: SharedArrayBufferStore,
   pub compiled_wasm_module_store: CompiledWasmModuleStore,
   maybe_resolver: Option<Arc<dyn deno_graph::source::Resolver + Send + Sync>>,
+  maybe_file_watcher_reporter: Option<FileWatcherReporter>,
 }
 
 impl Deref for ProcState {
@@ -92,6 +95,41 @@ impl Deref for ProcState {
 
 impl ProcState {
   pub async fn build(flags: Arc<flags::Flags>) -> Result<Self, AnyError> {
+    Self::build_with_sender(flags, None).await
+  }
+
+  pub async fn build_for_file_watcher(
+    flags: Arc<flags::Flags>,
+    files_to_watch_sender: tokio::sync::mpsc::UnboundedSender<Vec<PathBuf>>,
+  ) -> Result<Self, AnyError> {
+    let ps = Self::build_with_sender(
+      flags.clone(),
+      Some(files_to_watch_sender.clone()),
+    )
+    .await?;
+
+    // Add the extra files listed in the watch flag
+    if let Some(watch_paths) = &flags.watch {
+      files_to_watch_sender.send(watch_paths.clone()).unwrap();
+    }
+
+    if let Ok(Some(import_map_path)) =
+      config_file::resolve_import_map_specifier(
+        ps.flags.import_map_path.as_deref(),
+        ps.maybe_config_file.as_ref(),
+      )
+      .map(|ms| ms.and_then(|ref s| s.to_file_path().ok()))
+    {
+      files_to_watch_sender.send(vec![import_map_path]).unwrap();
+    }
+
+    Ok(ps)
+  }
+
+  async fn build_with_sender(
+    flags: Arc<flags::Flags>,
+    maybe_sender: Option<tokio::sync::mpsc::UnboundedSender<Vec<PathBuf>>>,
+  ) -> Result<Self, AnyError> {
     let maybe_custom_root = flags
       .cache_path
       .clone()
@@ -209,6 +247,12 @@ impl ProcState {
       None
     };
 
+    let maybe_file_watcher_reporter =
+      maybe_sender.map(|sender| FileWatcherReporter {
+        sender,
+        file_paths: Arc::new(Mutex::new(vec![])),
+      });
+
     Ok(ProcState(Arc::new(Inner {
       dir,
       coverage_dir,
@@ -225,6 +269,7 @@ impl ProcState {
       shared_array_buffer_store,
       compiled_wasm_module_store,
       maybe_resolver,
+      maybe_file_watcher_reporter,
     })))
   }
 
@@ -358,6 +403,13 @@ impl ProcState {
       reload: reload_on_watch,
     };
 
+    let maybe_file_watcher_reporter: Option<&dyn deno_graph::source::Reporter> =
+      if let Some(reporter) = &self.maybe_file_watcher_reporter {
+        Some(reporter)
+      } else {
+        None
+      };
+
     let graph = create_graph(
       roots.clone(),
       is_dynamic,
@@ -366,7 +418,7 @@ impl ProcState {
       maybe_resolver,
       maybe_locker,
       None,
-      None,
+      maybe_file_watcher_reporter,
     )
     .await;
 
@@ -719,3 +771,27 @@ fn source_map_from_code(code: String) -> Option<Vec<u8>> {
     None
   }
 }
+
+#[derive(Debug)]
+struct FileWatcherReporter {
+  sender: tokio::sync::mpsc::UnboundedSender<Vec<PathBuf>>,
+  file_paths: Arc<Mutex<Vec<PathBuf>>>,
+}
+
+impl deno_graph::source::Reporter for FileWatcherReporter {
+  fn on_load(
+    &self,
+    specifier: &ModuleSpecifier,
+    modules_done: usize,
+    modules_total: usize,
+  ) {
+    let mut file_paths = self.file_paths.lock();
+    if specifier.scheme() == "file" {
+      file_paths.push(specifier.to_file_path().unwrap());
+    }
+
+    if modules_done == modules_total {
+      self.sender.send(file_paths.drain(..).collect()).unwrap();
+    }
+  }
+}

cli/tests/integration/watcher_tests.rs

@@ -48,15 +48,22 @@ fn read_all_lints(stderr_lines: &mut impl Iterator<Item = String>) -> String {
   str
 }
 
-fn wait_for(s: &str, lines: &mut impl Iterator<Item = String>) {
+fn wait_for(
+  condition: impl Fn(&str) -> bool,
+  lines: &mut impl Iterator<Item = String>,
+) {
   loop {
     let msg = lines.next().unwrap();
-    if msg.contains(s) {
+    if condition(&msg) {
       break;
     }
   }
 }
 
+fn wait_contains(s: &str, lines: &mut impl Iterator<Item = String>) {
+  wait_for(|msg| msg.contains(s), lines)
+}
+
 fn read_line(s: &str, lines: &mut impl Iterator<Item = String>) -> String {
   lines.find(|m| m.contains(s)).unwrap()
 }
@@ -408,7 +415,7 @@ fn bundle_js_watch() {
   assert_contains!(stderr_lines.next().unwrap(), "mod6.bundle.js");
   let file = PathBuf::from(&bundle);
   assert!(file.is_file());
-  wait_for("Bundle finished", &mut stderr_lines);
+  wait_contains("Bundle finished", &mut stderr_lines);
 
   write(&file_to_watch, "console.log('Hello world2');").unwrap();
 
@@ -420,14 +427,14 @@ fn bundle_js_watch() {
   assert_contains!(stderr_lines.next().unwrap(), "mod6.bundle.js");
   let file = PathBuf::from(&bundle);
   assert!(file.is_file());
-  wait_for("Bundle finished", &mut stderr_lines);
+  wait_contains("Bundle finished", &mut stderr_lines);
 
   // Confirm that the watcher keeps on working even if the file is updated and has invalid syntax
   write(&file_to_watch, "syntax error ^^").unwrap();
 
   assert_contains!(stderr_lines.next().unwrap(), "File change detected!");
   assert_contains!(stderr_lines.next().unwrap(), "error: ");
-  wait_for("Bundle failed", &mut stderr_lines);
+  wait_contains("Bundle failed", &mut stderr_lines);
   check_alive_then_kill(deno);
 }
 
@@ -470,15 +477,15 @@ fn bundle_watch_not_exit() {
   assert_contains!(stderr_lines.next().unwrap(), "file_to_watch.ts");
   assert_contains!(stderr_lines.next().unwrap(), "target.js");
 
-  wait_for("Bundle finished", &mut stderr_lines);
+  wait_contains("Bundle finished", &mut stderr_lines);
 
   // bundled file is created
   assert!(target_file.is_file());
   check_alive_then_kill(deno);
 }
 
-#[flaky_test::flaky_test]
-fn run_watch() {
+#[test]
+fn run_watch_no_dynamic() {
   let t = TempDir::new();
   let file_to_watch = t.path().join("file_to_watch.js");
   write(&file_to_watch, "console.log('Hello world');").unwrap();
@@ -488,6 +495,8 @@ fn run_watch() {
     .arg("run")
     .arg("--watch")
     .arg("--unstable")
+    .arg("-L")
+    .arg("debug")
     .arg(&file_to_watch)
     .env("NO_COLOR", "1")
     .stdout(std::process::Stdio::piped())
@@ -496,15 +505,21 @@ fn run_watch() {
     .unwrap();
   let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
 
-  assert_contains!(stdout_lines.next().unwrap(), "Hello world");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Hello world", &mut stdout_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
+    &mut stderr_lines,
+  );
 
   // Change content of the file
   write(&file_to_watch, "console.log('Hello world2');").unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stdout_lines.next().unwrap(), "Hello world2");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("Hello world2", &mut stdout_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
+    &mut stderr_lines,
+  );
 
   // Add dependency
   let another_file = t.path().join("another_file.js");
@@ -515,23 +530,32 @@ fn run_watch() {
   )
   .unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stdout_lines.next().unwrap(), '0');
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("0", &mut stdout_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("another_file.js"),
+    &mut stderr_lines,
+  );
 
   // Confirm that restarting occurs when a new file is updated
   write(&another_file, "export const foo = 42;").unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stdout_lines.next().unwrap(), "42");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("42", &mut stdout_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
+    &mut stderr_lines,
+  );
 
   // Confirm that the watcher keeps on working even if the file is updated and has invalid syntax
   write(&file_to_watch, "syntax error ^^").unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stderr_lines.next().unwrap(), "error:");
-  wait_for("Process failed", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("error:", &mut stderr_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
+    &mut stderr_lines,
+  );
 
   // Then restore the file
   write(
@@ -540,23 +564,29 @@ fn run_watch() {
   )
   .unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stdout_lines.next().unwrap(), "42");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("42", &mut stdout_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("another_file.js"),
+    &mut stderr_lines,
+  );
 
   // Update the content of the imported file with invalid syntax
   write(&another_file, "syntax error ^^").unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stderr_lines.next().unwrap(), "error:");
-  wait_for("Process failed", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("error:", &mut stderr_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("another_file.js"),
+    &mut stderr_lines,
+  );
 
   // Modify the imported file and make sure that restarting occurs
   write(&another_file, "export const foo = 'modified!';").unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  assert_contains!(stdout_lines.next().unwrap(), "modified!");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("modified!", &mut stdout_lines);
+  wait_contains("Watching paths", &mut stderr_lines);
   check_alive_then_kill(child);
 }
 
@@ -581,6 +611,8 @@ fn run_watch_external_watch_files() {
     .current_dir(util::testdata_path())
     .arg("run")
     .arg(watch_arg)
+    .arg("-L")
+    .arg("debug")
     .arg("--unstable")
     .arg(&file_to_watch)
     .env("NO_COLOR", "1")
@@ -589,15 +621,20 @@ fn run_watch_external_watch_files() {
     .spawn()
     .unwrap();
   let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
-
-  assert_contains!(stdout_lines.next().unwrap(), "Hello world");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Process started", &mut stderr_lines);
+  wait_contains("Hello world", &mut stdout_lines);
+  wait_for(
+    |m| {
+      m.contains("Watching paths") && m.contains("external_file_to_watch.txt")
+    },
+    &mut stderr_lines,
+  );
 
   // Change content of the external file
   write(&external_file_to_watch, "Hello world2").unwrap();
 
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("Process finished", &mut stderr_lines);
   check_alive_then_kill(child);
 }
 
@@ -625,6 +662,8 @@ fn run_watch_load_unload_events() {
     .arg("run")
     .arg("--watch")
     .arg("--unstable")
+    .arg("-L")
+    .arg("debug")
     .arg(&file_to_watch)
     .env("NO_COLOR", "1")
     .env("DENO_FUTURE_CHECK", "1")
@@ -635,7 +674,11 @@ fn run_watch_load_unload_events() {
   let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
 
   // Wait for the first load event to fire
-  assert_contains!(stdout_lines.next().unwrap(), "load");
+  wait_contains("load", &mut stdout_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
+    &mut stderr_lines,
+  );
 
   // Change content of the file, this time without an interval to keep it alive.
   write(
@@ -653,18 +696,16 @@ fn run_watch_load_unload_events() {
   .unwrap();
 
   // Wait for the restart
-  let next_line = stderr_lines.next().unwrap();
-  assert_contains!(&next_line, "Process started");
-  assert_contains!(stderr_lines.next().unwrap(), "Restarting");
+  wait_contains("Restarting", &mut stderr_lines);
 
   // Confirm that the unload event was dispatched from the first run
-  assert_contains!(stdout_lines.next().unwrap(), "unload");
+  wait_contains("unload", &mut stdout_lines);
 
   // Followed by the load event of the second run
-  assert_contains!(stdout_lines.next().unwrap(), "load");
+  wait_contains("load", &mut stdout_lines);
 
   // Which is then unloaded as there is nothing keeping it alive.
-  assert_contains!(stdout_lines.next().unwrap(), "unload");
+  wait_contains("unload", &mut stdout_lines);
   check_alive_then_kill(child);
 }
 
@@ -680,6 +721,8 @@ fn run_watch_not_exit() {
     .arg("run")
     .arg("--watch")
     .arg("--unstable")
+    .arg("-L")
+    .arg("debug")
     .arg(&file_to_watch)
     .env("NO_COLOR", "1")
     .env("DENO_FUTURE_CHECK", "1")
@@ -689,19 +732,19 @@ fn run_watch_not_exit() {
     .unwrap();
   let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
 
-  let next_line = stderr_lines.next().unwrap();
-  assert_contains!(&next_line, "Process started");
-  assert_contains!(stderr_lines.next().unwrap(), "error:");
-  assert_contains!(stderr_lines.next().unwrap(), "Process failed");
+  wait_contains("Process started", &mut stderr_lines);
+  wait_contains("error:", &mut stderr_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("file_to_watch.js"),
+    &mut stderr_lines,
+  );
 
   // Make sure the watcher actually restarts and works fine with the proper syntax
   write(&file_to_watch, "console.log(42);").unwrap();
 
-  let next_line = stderr_lines.next().unwrap();
-  assert_contains!(&next_line, CLEAR_SCREEN);
-  assert_contains!(&next_line, "Restarting");
-  assert_contains!(stdout_lines.next().unwrap(), "42");
-  wait_for("Process finished", &mut stderr_lines);
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains("42", &mut stdout_lines);
+  wait_contains("Process finished", &mut stderr_lines);
   check_alive_then_kill(child);
 }
 
@@ -756,7 +799,7 @@ fn run_watch_with_import_map_and_relative_paths() {
   check_alive_then_kill(child);
 }
 
-#[flaky_test]
+#[test]
 fn test_watch() {
   let t = TempDir::new();
 
@@ -779,7 +822,7 @@ fn test_watch() {
     stdout_lines.next().unwrap(),
     "0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out"
   );
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   let foo_file = t.path().join("foo.js");
   let bar_file = t.path().join("bar.js");
@@ -806,7 +849,7 @@ fn test_watch() {
   stdout_lines.next();
   stdout_lines.next();
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Change content of the file
   write(
@@ -821,7 +864,7 @@ fn test_watch() {
   stdout_lines.next();
   stdout_lines.next();
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Add test
   let another_test = t.path().join("new_test.js");
@@ -832,7 +875,7 @@ fn test_watch() {
   stdout_lines.next();
   stdout_lines.next();
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Confirm that restarting occurs when a new file is updated
   write(&another_test, "Deno.test('another one', () => 3 + 3); Deno.test('another another one', () => 4 + 4)")
@@ -844,7 +887,7 @@ fn test_watch() {
   stdout_lines.next();
   stdout_lines.next();
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Confirm that the watcher keeps on working even if the file is updated and has invalid syntax
   write(&another_test, "syntax error ^^").unwrap();
@@ -860,7 +903,7 @@ fn test_watch() {
   stdout_lines.next();
   stdout_lines.next();
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Confirm that the watcher keeps on working even if the file is updated and the test fails
   // This also confirms that it restarts when dependencies change
@@ -872,9 +915,9 @@ fn test_watch() {
   assert_contains!(stderr_lines.next().unwrap(), "Restarting");
   assert_contains!(stdout_lines.next().unwrap(), "running 1 test");
   assert_contains!(stdout_lines.next().unwrap(), "FAILED");
-  wait_for("test result", &mut stdout_lines);
+  wait_contains("test result", &mut stdout_lines);
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Then restore the file
   write(&foo_file, "export default function foo() { 1 + 1 }").unwrap();
@@ -884,7 +927,7 @@ fn test_watch() {
   stdout_lines.next();
   stdout_lines.next();
   stdout_lines.next();
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   // Test that circular dependencies work fine
   write(
@@ -923,7 +966,7 @@ fn test_watch_doc() {
     stdout_lines.next().unwrap(),
     "0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out"
   );
-  wait_for("Test finished", &mut stderr_lines);
+  wait_contains("Test finished", &mut stderr_lines);
 
   let foo_file = t.path().join("foo.ts");
   write(
@@ -979,23 +1022,48 @@ fn test_watch_module_graph_error_referrer() {
   let line3 = stderr_lines.next().unwrap();
   assert_contains!(&line3, "    at ");
   assert_contains!(&line3, "file_to_watch.js");
-  wait_for("Process failed", &mut stderr_lines);
+  wait_contains("Process finished", &mut stderr_lines);
   check_alive_then_kill(child);
 }
 
 #[test]
-fn watch_with_no_clear_screen_flag() {
+fn run_watch_dynamic_imports() {
   let t = TempDir::new();
   let file_to_watch = t.path().join("file_to_watch.js");
-  write(&file_to_watch, "export const foo = 0;").unwrap();
+  write(
+    &file_to_watch,
+    r#"
+    console.log("Hopefully dynamic import will be watched...");
+    await import("./imported.js");
+    "#,
+  )
+  .unwrap();
+  let file_to_watch2 = t.path().join("imported.js");
+  write(
+    &file_to_watch2,
+    r#"
+    import "./imported2.js";
+    console.log("I'm dynamically imported and I cause restarts!");
+    "#,
+  )
+  .unwrap();
+  let file_to_watch3 = t.path().join("imported2.js");
+  write(
+    &file_to_watch3,
+    r#"
+    console.log("I'm statically imported from the dynamic import");
+    "#,
+  )
+  .unwrap();
 
-  // choose deno run subcommand to test --no-clear-screen flag
   let mut child = util::deno_cmd()
     .current_dir(util::testdata_path())
     .arg("run")
     .arg("--watch")
-    .arg("--no-clear-screen")
     .arg("--unstable")
+    .arg("--allow-read")
+    .arg("-L")
+    .arg("debug")
     .arg(&file_to_watch)
     .env("NO_COLOR", "1")
     .env("DENO_FUTURE_CHECK", "1")
@@ -1003,30 +1071,49 @@ fn watch_with_no_clear_screen_flag() {
     .stderr(std::process::Stdio::piped())
     .spawn()
     .unwrap();
-  let (_, mut stderr_lines) = child_lines(&mut child);
+  let (mut stdout_lines, mut stderr_lines) = child_lines(&mut child);
 
-  let next_line = stderr_lines.next().unwrap();
+  assert_contains!(stderr_lines.next().unwrap(), "Process started");
 
-  // no clear screen
-  assert!(!&next_line.contains(CLEAR_SCREEN));
-  assert_contains!(&next_line, "Process started");
-  assert_contains!(
-    stderr_lines.next().unwrap(),
-    "Process finished. Restarting on file change..."
+  wait_contains(
+    "Hopefully dynamic import will be watched...",
+    &mut stdout_lines,
+  );
+  wait_contains(
+    "I'm statically imported from the dynamic import",
+    &mut stdout_lines,
+  );
+  wait_contains(
+    "I'm dynamically imported and I cause restarts!",
+    &mut stdout_lines,
   );
 
-  // Change content of the file
-  write(&file_to_watch, "export const bar = 0;").unwrap();
+  wait_contains("finished", &mut stderr_lines);
+  wait_for(
+    |m| m.contains("Watching paths") && m.contains("imported2.js"),
+    &mut stderr_lines,
+  );
 
-  let next_line = stderr_lines.next().unwrap();
+  write(
+    &file_to_watch3,
+    r#"
+    console.log("I'm statically imported from the dynamic import and I've changed");
+    "#,
+  )
+  .unwrap();
 
-  // no clear screen
-  assert!(!&next_line.contains(CLEAR_SCREEN));
-
-  assert_contains!(&next_line, "Watcher File change detected! Restarting!");
-  assert_contains!(
-    stderr_lines.next().unwrap(),
-    "Process finished. Restarting on file change..."
+  wait_contains("Restarting", &mut stderr_lines);
+  wait_contains(
+    "Hopefully dynamic import will be watched...",
+    &mut stdout_lines,
+  );
+  wait_contains(
+    "I'm statically imported from the dynamic import and I've changed",
+    &mut stdout_lines,
+  );
+  wait_contains(
+    "I'm dynamically imported and I cause restarts!",
+    &mut stdout_lines,
   );
 
   check_alive_then_kill(child);