Lazy load @parcel/watcher and fallback to chokidar

Author: ntkme

lib/src/io/js.dart

@@ -254,60 +254,68 @@ Future<Stream<WatchEvent>> watchDir(String path, {bool poll = false}) async {
     throw UnsupportedError("watchDir() is only supported on Node.js");
   }
 
+  if (poll || parcelWatcher == null) {
+    return _chokidarWatchDir(path, poll: poll);
+  } else {
+    return _parcelWatcherWatchDir(path);
+  }
+}
+
+Future<Stream<WatchEvent>> _chokidarWatchDir(String path, {bool poll = false}) {
   // Don't assign the controller until after the ready event fires. Otherwise,
   // Chokidar will give us a bunch of add events for files that already exist.
   StreamController<WatchEvent>? controller;
-  if (poll) {
-    var watcher = chokidar.watch(path, ChokidarOptions(usePolling: true));
-    watcher
-      ..on(
-          'add',
-          allowInterop((String path, [void _]) =>
-              controller?.add(WatchEvent(ChangeType.ADD, path))))
-      ..on(
-          'change',
-          allowInterop((String path, [void _]) =>
-              controller?.add(WatchEvent(ChangeType.MODIFY, path))))
-      ..on(
-          'unlink',
-          allowInterop((String path) =>
-              controller?.add(WatchEvent(ChangeType.REMOVE, path))))
-      ..on(
-          'error', allowInterop((Object error) => controller?.addError(error)));
-
-    var completer = Completer<Stream<WatchEvent>>();
-    watcher.on('ready', allowInterop(() {
-      // dart-lang/sdk#45348
-      var stream = (controller = StreamController<WatchEvent>(onCancel: () {
-        watcher.close();
-      }))
-          .stream;
-      completer.complete(stream);
-    }));
-
-    return completer.future;
-  } else {
-    var subscription = await ParcelWatcher.subscribeFuture(path,
-        (Object? error, List<ParcelWatcherEvent> events) {
-      if (error != null) {
-        controller?.addError(error);
-      } else {
-        for (var event in events) {
-          switch (event.type) {
-            case 'create':
-              controller?.add(WatchEvent(ChangeType.ADD, event.path));
-            case 'update':
-              controller?.add(WatchEvent(ChangeType.MODIFY, event.path));
-            case 'delete':
-              controller?.add(WatchEvent(ChangeType.REMOVE, event.path));
-          }
+  var watcher = chokidar.watch(path, ChokidarOptions(usePolling: poll));
+  watcher
+    ..on(
+        'add',
+        allowInterop((String path, [void _]) =>
+            controller?.add(WatchEvent(ChangeType.ADD, path))))
+    ..on(
+        'change',
+        allowInterop((String path, [void _]) =>
+            controller?.add(WatchEvent(ChangeType.MODIFY, path))))
+    ..on(
+        'unlink',
+        allowInterop((String path) =>
+            controller?.add(WatchEvent(ChangeType.REMOVE, path))))
+    ..on('error', allowInterop((Object error) => controller?.addError(error)));
+
+  var completer = Completer<Stream<WatchEvent>>();
+  watcher.on('ready', allowInterop(() {
+    // dart-lang/sdk#45348
+    var stream = (controller = StreamController<WatchEvent>(onCancel: () {
+      watcher.close();
+    }))
+        .stream;
+    completer.complete(stream);
+  }));
+
+  return completer.future;
+}
+
+Future<Stream<WatchEvent>> _parcelWatcherWatchDir(String path) async {
+  StreamController<WatchEvent>? controller;
+  var subscription = await parcelWatcher!.subscribe(path,
+      (Object? error, List<ParcelWatcherEvent> events) {
+    if (error != null) {
+      controller?.addError(error);
+    } else {
+      for (var event in events) {
+        switch (event.type) {
+          case 'create':
+            controller?.add(WatchEvent(ChangeType.ADD, event.path));
+          case 'update':
+            controller?.add(WatchEvent(ChangeType.MODIFY, event.path));
+          case 'delete':
+            controller?.add(WatchEvent(ChangeType.REMOVE, event.path));
         }
       }
-    });
+    }
+  });
 
-    return (controller = StreamController<WatchEvent>(onCancel: () {
-      subscription.unsubscribe();
-    }))
-        .stream;
-  }
+  return (controller = StreamController<WatchEvent>(onCancel: () {
+    subscription.unsubscribe();
+  }))
+      .stream;
 }

lib/src/js/parcel_watcher.dart

@@ -2,43 +2,48 @@
 // MIT-style license that can be found in the LICENSE file or at
 // https://opensource.org/licenses/MIT.
 
-import 'package:js/js.dart';
-import 'package:node_interop/js.dart';
-import 'package:node_interop/util.dart';
+import 'dart:js_interop';
 
 @JS()
-class ParcelWatcherSubscription {
+extension type ParcelWatcherSubscription(JSObject _) implements JSObject {
   external void unsubscribe();
 }
 
 @JS()
-class ParcelWatcherEvent {
+extension type ParcelWatcherEvent(JSObject _) implements JSObject {
   external String get type;
   external String get path;
 }
 
 /// The @parcel/watcher module.
 ///
 /// See [the docs on npm](https://www.npmjs.com/package/@parcel/watcher).
-@JS('parcel_watcher')
-class ParcelWatcher {
-  external static Promise subscribe(String path, Function callback);
-  static Future<ParcelWatcherSubscription> subscribeFuture(String path,
+@JS()
+extension type ParcelWatcher(JSObject _) implements JSObject {
+  @JS('subscribe')
+  external JSPromise<ParcelWatcherSubscription> _subscribe(
+      String path, JSFunction callback);
+  Future<ParcelWatcherSubscription> subscribe(String path,
           void Function(Object? error, List<ParcelWatcherEvent>) callback) =>
-      promiseToFuture(
-          subscribe(path, allowInterop((Object? error, List<dynamic> events) {
-        callback(error, events.cast<ParcelWatcherEvent>());
-      })));
+      _subscribe(
+              path,
+              (JSObject? error, JSArray<ParcelWatcherEvent> events) {
+                callback(error, events.toDart);
+              }.toJS)
+          .toDart;
 
-  external static Promise getEventsSince(String path, String snapshotPath);
-  static Future<List<ParcelWatcherEvent>> getEventsSinceFuture(
-      String path, String snapshotPath) async {
-    List<dynamic> events =
-        await promiseToFuture(getEventsSince(path, snapshotPath));
-    return events.cast<ParcelWatcherEvent>();
-  }
+  @JS('getEventsSince')
+  external JSPromise<JSArray<ParcelWatcherEvent>> _getEventsSince(
+      String path, String snapshotPath);
+  Future<List<ParcelWatcherEvent>> getEventsSince(
+          String path, String snapshotPath) async =>
+      (await _getEventsSince(path, snapshotPath).toDart).toDart;
 
-  external static Promise writeSnapshot(String path, String snapshotPath);
-  static Future<void> writeSnapshotFuture(String path, String snapshotPath) =>
-      promiseToFuture(writeSnapshot(path, snapshotPath));
+  @JS('writeSnapshot')
+  external JSPromise<JSAny> _writeSnapshot(String path, String snapshotPath);
+  Future<void> writeSnapshot(String path, String snapshotPath) =>
+      _writeSnapshot(path, snapshotPath).toDart;
 }
+
+@JS('parcel_watcher')
+external ParcelWatcher? get parcelWatcher;

lib/src/parse/parser.dart

@@ -651,7 +651,7 @@ class Parser {
     var span = scanner.spanFrom(state);
     return _interpolationMap == null
         ? span
-        : LazyFileSpan(() => _interpolationMap!.mapSpan(span));
+        : LazyFileSpan(() => _interpolationMap.mapSpan(span));
   }
 
   /// Throws an error associated with [span].

lib/src/visitor/async_evaluate.dart

@@ -1812,7 +1812,7 @@ final class _EvaluateVisitor
     if (result != null) {
       isDependency = _inDependency;
     } else {
-      result = await _nodeImporter!.loadAsync(originalUrl, previous, forImport);
+      result = await _nodeImporter.loadAsync(originalUrl, previous, forImport);
       if (result == null) return null;
       isDependency = true;
     }

lib/src/visitor/evaluate.dart

@@ -5,7 +5,7 @@
 // DO NOT EDIT. This file was generated from async_evaluate.dart.
 // See tool/grind/synchronize.dart for details.
 //
-// Checksum: 396c8f169d95c601598b8c3be1f4b948ca22effa
+// Checksum: 3986f5db33dd220dcd971a39e8587ca4e52d9a3f
 //
 // ignore_for_file: unused_import
 
@@ -1808,7 +1808,7 @@ final class _EvaluateVisitor
     if (result != null) {
       isDependency = _inDependency;
     } else {
-      result = _nodeImporter!.load(originalUrl, previous, forImport);
+      result = _nodeImporter.load(originalUrl, previous, forImport);
       if (result == null) return null;
       isDependency = true;
     }

pkg/sass_api/pubspec.yaml

@@ -7,7 +7,7 @@ description: Additional APIs for Dart Sass.
 homepage: https://github.com/sass/dart-sass
 
 environment:
-  sdk: ">=3.0.0 <4.0.0"
+  sdk: ">=3.3.0 <4.0.0"
 
 dependencies:
   sass: 1.80.5

pubspec.yaml

@@ -8,13 +8,16 @@ executables:
   sass: sass
 
 environment:
-  sdk: ">=3.0.0 <4.0.0"
+  sdk: ">=3.3.0 <4.0.0"
 
 dependencies:
   args: ^2.0.0
   async: ^2.5.0
   charcode: ^1.2.0
-  cli_pkg: ^2.8.0
+  cli_pkg:
+    git:
+      url: https://github.com/google/dart_cli_pkg.git
+      ref: refs/pull/169/head
   cli_repl: ^0.2.1
   collection: ^1.16.0
   http: ^1.1.0

tool/grind.dart

@@ -35,7 +35,8 @@ void main(List<String> args) {
   pkg.homebrewFormula.value = "Formula/sass.rb";
   pkg.homebrewEditFormula.value = _updateHomebrewLanguageRevision;
   pkg.jsRequires.value = [
-    pkg.JSRequire("@parcel/watcher", target: pkg.JSRequireTarget.cli),
+    pkg.JSRequire("@parcel/watcher",
+        target: pkg.JSRequireTarget.cli, lazy: true, optional: true),
     pkg.JSRequire("immutable", target: pkg.JSRequireTarget.all),
     pkg.JSRequire("chokidar", target: pkg.JSRequireTarget.cli),
     pkg.JSRequire("readline", target: pkg.JSRequireTarget.cli),