1 files changed, 99 insertions, 0 deletions
diff --git a/cli/watcher.rs b/cli/watcher.rs
new file mode 100644
index 000000000..f9c2c1b42
--- /dev/null
+++ b/cli/watcher.rs
@@ -0,0 +1,99 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+use crate::args::CliOptions;
+use crate::cache::ParsedSourceCache;
+use crate::graph_util::ModuleGraphContainer;
+use crate::module_loader::CjsResolutionStore;
+
+use deno_core::parking_lot::Mutex;
+use deno_core::ModuleSpecifier;
+
+use std::path::PathBuf;
+use std::sync::Arc;
+
+pub struct FileWatcher {
+  cli_options: Arc<CliOptions>,
+  cjs_resolutions: Arc<CjsResolutionStore>,
+  graph_container: Arc<ModuleGraphContainer>,
+  maybe_reporter: Option<FileWatcherReporter>,
+  parsed_source_cache: Arc<ParsedSourceCache>,
+}
+
+impl FileWatcher {
+  pub fn new(
+    cli_options: Arc<CliOptions>,
+    cjs_resolutions: Arc<CjsResolutionStore>,
+    graph_container: Arc<ModuleGraphContainer>,
+    maybe_reporter: Option<FileWatcherReporter>,
+    parsed_source_cache: Arc<ParsedSourceCache>,
+  ) -> Self {
+    Self {
+      cli_options,
+      cjs_resolutions,
+      parsed_source_cache,
+      graph_container,
+      maybe_reporter,
+    }
+  }
+  /// Reset all runtime state to its default. This should be used on file
+  /// watcher restarts.
+  pub fn reset(&self) {
+    self.cjs_resolutions.clear();
+    self.parsed_source_cache.clear();
+    self.graph_container.clear();
+
+    self.init_watcher();
+  }
+
+  // Add invariant files like the import map and explicit watch flag list to
+  // the watcher. Dedup for build_for_file_watcher and reset_for_file_watcher.
+  pub fn init_watcher(&self) {
+    let files_to_watch_sender = match &self.maybe_reporter {
+      Some(reporter) => &reporter.sender,
+      None => return,
+    };
+    if let Some(watch_paths) = self.cli_options.watch_paths() {
+      files_to_watch_sender.send(watch_paths.clone()).unwrap();
+    }
+    if let Ok(Some(import_map_path)) = self
+      .cli_options
+      .resolve_import_map_specifier()
+      .map(|ms| ms.and_then(|ref s| s.to_file_path().ok()))
+    {
+      files_to_watch_sender.send(vec![import_map_path]).unwrap();
+    }
+  }
+}
+
+#[derive(Clone, Debug)]
+pub struct FileWatcherReporter {
+  sender: tokio::sync::mpsc::UnboundedSender<Vec<PathBuf>>,
+  file_paths: Arc<Mutex<Vec<PathBuf>>>,
+}
+
+impl FileWatcherReporter {
+  pub fn new(sender: tokio::sync::mpsc::UnboundedSender<Vec<PathBuf>>) -> Self {
+    Self {
+      sender,
+      file_paths: Default::default(),
+    }
+  }
+}
+
+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();
+    }
+  }
+}