[Shared Resources] dart-sass implementation

lib/src/js.dart

@@ -5,6 +5,7 @@
 import 'js/exception.dart';
 import 'js/exports.dart';
 import 'js/compile.dart';
+import 'js/compiler.dart';
 import 'js/legacy.dart';
 import 'js/legacy/types.dart';
 import 'js/legacy/value.dart';
@@ -24,6 +25,11 @@ void main() {
   exports.compileAsync = allowInteropNamed('sass.compileAsync', compileAsync);
   exports.compileStringAsync =
       allowInteropNamed('sass.compileStringAsync', compileStringAsync);
+  exports.initCompiler = allowInteropNamed('sass.initCompiler', initCompiler);
+  exports.initAsyncCompiler =
+      allowInteropNamed('sass.initAsyncCompiler', initAsyncCompiler);
+  exports.Compiler = compilerClass;
+  exports.AsyncCompiler = asyncCompilerClass;
   exports.Value = valueClass;
   exports.SassBoolean = booleanClass;
   exports.SassArgumentList = argumentListClass;

lib/src/js/compiler.dart

@@ -0,0 +1,104 @@
+import 'dart:js_util';
+
+import 'package:node_interop/js.dart';
+
+import 'compile.dart';
+import 'compile_options.dart';
+import 'reflection.dart';
+import 'utils.dart';
+
+class Compiler {
+  bool _disposed = false;
+
+  void throwIfDisposed() {
+    if (_disposed) {
+      jsThrow(JsError('Compiler has already been disposed.'));
+    }
+  }
+}
+
+class AsyncCompiler extends Compiler {
+  final Set<Promise> _compilations = {};
+
+  /// Adds a compilation to the pending set and removes it when it's done.
+  void _addCompilation(Promise compilation) {
+    _compilations.add(compilation);
+    compilation.then((value) {
+      _compilations.remove(compilation);
+    }, (error) {
+      _compilations.remove(compilation);
+    });
+  }
+}
+
+/// The JS API Compiler class
+///
+/// See https://github.com/sass/sass/spec/tree/main/js-api/compile.d.ts for
+/// details.
+final JSClass compilerClass = () {
+  var jsClass = createJSClass('sass.Compiler', () => Compiler());
+
+  jsClass.defineMethods({
+    'compile': (Compiler self, String path, [CompileOptions? options]) {
+      self.throwIfDisposed();
+      return compile(path, options);
+    },
+    'compileString': (Compiler self, String source,
+        [CompileStringOptions? options]) {
+      self.throwIfDisposed();
+      return compileString(source, options);
+    },
+    'dispose': (Compiler self) {
+      self._disposed = true;
+    },
+  });
+
+  getJSClass(Compiler()).injectSuperclass(jsClass);
+  return jsClass;
+}();
+
+/// Returns an instance of the JS API Compiler class
+///
+/// See https://github.com/sass/sass/spec/tree/main/js-api/compile.d.ts for
+/// details.
+Compiler initCompiler() => Compiler();
+
+/// The JS AsyncCompiler class
+///
+/// See https://github.com/sass/sass/spec/tree/main/js-api/compile.d.ts for
+/// details.
+final JSClass asyncCompilerClass = () {
+  var jsClass = createJSClass('sass.AsyncCompiler', () => AsyncCompiler());
+
+  jsClass.defineMethods({
+    'compileAsync': (AsyncCompiler self, String path,
+        [CompileOptions? options]) {
+      self.throwIfDisposed();
+      var compilation = compileAsync(path, options);
+      self._addCompilation(compilation);
+      return compilation;
+    },
+    'compileStringAsync': (AsyncCompiler self, String source,
+        [CompileStringOptions? options]) {
+      self.throwIfDisposed();
+      var compilation = compileStringAsync(source, options);
+      self._addCompilation(compilation);
+      return compilation;
+    },
+    'dispose': (AsyncCompiler self) {
+      self._disposed = true;
+      return futureToPromise((() async {
+        await Future.wait(self._compilations.map(promiseToFuture<Object>));
+      })());
+    }
+  });
+
+  getJSClass(AsyncCompiler()).injectSuperclass(jsClass);
+  return jsClass;
+}();
+
+/// Resolves an instance of the JS API AsyncCompiler class
+///
+/// See https://github.com/sass/sass/spec/tree/main/js-api/compile.d.ts for
+/// details.
+Promise initAsyncCompiler() => futureToPromise((() async => AsyncCompiler())());

lib/src/js/exports.dart

@@ -19,6 +19,10 @@ class Exports {
   external set compileStringAsync(Function function);
   external set compile(Function function);
   external set compileAsync(Function function);
+  external set initCompiler(Function function);
+  external set initAsyncCompiler(Function function);
+  external set Compiler(JSClass function);
+  external set AsyncCompiler(JSClass function);
   external set info(String info);
   external set Exception(JSClass function);
   external set Logger(LoggerNamespace namespace);

tool/grind.dart

@@ -51,6 +51,10 @@ void main(List<String> args) {
     'compileAsync',
     'compileString',
     'compileStringAsync',
+    'initCompiler',
+    'initAsyncCompiler',
+    'Compiler',
+    'AsyncCompiler',
     'Logger',
     'SassArgumentList',
     'SassBoolean',