Add Variable Declaration Support

web_generator/lib/src/ast.dart

@@ -0,0 +1,169 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'package:code_builder/code_builder.dart';
+
+import 'interop_gen/generate.dart';
+import 'interop_gen/namer.dart';
+
+sealed class Node {
+  abstract final String? name;
+  abstract final ID id;
+  final String? dartName;
+
+  Node() : dartName = null;
+}
+
+abstract class Declaration extends Node {
+  @override
+  abstract final String name;
+
+  Spec emit();
+}
+
+abstract class NamedDeclaration extends Declaration {
+  ReferredType asReferredType([List<Type>? typeArgs]) =>
+      ReferredType(name: name, declaration: this, typeParams: typeArgs ?? []);
+}
+
+abstract interface class ExportableDeclaration extends Declaration {
+  /// Whether this declaration is exported.
+  bool get exported;
+}
+
+abstract class Type extends Node {
+  Reference emit();
+}
+
+enum PrimitiveType implements Type {
+  string('string'),
+  any('any'),
+  object('object'),
+  number('number'),
+  boolean('boolean'),
+  undefined('undefined'),
+  unknown('unknown');
+
+  const PrimitiveType(this.name);
+
+  @override
+  final String name;
+
+  @override
+  ID get id => ID(type: 'type', name: name);
+
+  // TODO(https://github.com/dart-lang/web/pull/386): Configuration options: double and num
+  @override
+  Reference emit() {
+    return switch (this) {
+      PrimitiveType.string => refer('String'),
+      PrimitiveType.any => refer('JSAny', 'dart:js_interop'),
+      PrimitiveType.object => refer('JSObject', 'dart:js_interop'),
+      PrimitiveType.number => refer('int'),
+      PrimitiveType.boolean => refer('bool'),
+      PrimitiveType.undefined => TypeReference((t) => t
+        ..symbol = 'JSAny'
+        ..url = 'dart:js_interop'
+        ..isNullable = true),
+      PrimitiveType.unknown => TypeReference((t) => t
+        ..symbol = 'JSAny'
+        ..url = 'dart:js_interop'
+        ..isNullable = true)
+    };
+  }
+
+  @override
+  String? get dartName => null;
+}
+
+// TODO(): Refactor name - not all types can be referred to
+//  (only specific types) Instead change this
+//  to represent `typeof` declarations.
+// TODO(): Create a shared type for such types that
+//  can be referred to (i.e namespace, interface, class)
+//  as a type `ReferrableDeclaration`.
+class ReferredType<T extends Declaration> extends Type {
+  @override
+  String name;
+
+  @override
+  ID get id => ID(type: 'type', name: name);
+
+  T declaration;
+
+  List<Type> typeParams;
+
+  ReferredType(
+      {required this.name,
+      required this.declaration,
+      this.typeParams = const []});
+
+  @override
+  Reference emit() {
+    // TODO: implement emit
+    throw UnimplementedError();
+  }
+}
+
+// TODO(https://github.com/dart-lang/web/issues/385): Implement Support for UnionType (including implementing `emit`)
+class UnionType extends Type {
+  List<Type> types;
+
+  UnionType({required this.types});
+
+  @override
+  ID get id => ID(type: 'type', name: types.map((t) => t.id).join('|'));
+
+  @override
+  Reference emit() {
+    throw UnimplementedError();
+  }
+
+  @override
+  String? get name => null;
+}
+
+class VariableDeclaration extends NamedDeclaration
+    implements ExportableDeclaration {
+  /// The variable modifier, as represented in TypeScript
+  VariableModifier modifier;
+
+  @override
+  String name;
+
+  Type type;
+
+  @override
+  bool exported;
+
+  VariableDeclaration(
+      {required this.name,
+      required this.type,
+      required this.modifier,
+      required this.exported});
+
+  @override
+  ID get id => ID(type: 'var', name: name);
+
+  @override
+  Spec emit() {
+    if (modifier == VariableModifier.$const) {
+      return Method((m) => m
+        ..name = name
+        ..type = MethodType.getter
+        ..annotations.add(generateJSAnnotation())
+        ..external = true
+        ..returns = type.emit());
+    } else {
+      // getter and setter -> single variable
+      return Field((f) => f
+        ..external = true
+        ..name = name
+        ..type = type.emit()
+        ..annotations.add(generateJSAnnotation()));
+    }
+  }
+}
+
+enum VariableModifier { let, $const, $var }

web_generator/lib/src/banned_names.dart

@@ -2,6 +2,75 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+/// Dart reserved keywords, used for resolving conflict with a name.
+///
+/// Source: https://dart.dev/guides/language/language-tour#keywords.
+const keywords = {
+  'abstract',
+  'as',
+  'assert',
+  'async',
+  'await',
+  'break',
+  'case',
+  'catch',
+  'class',
+  'const',
+  'continue',
+  'covariant',
+  'default',
+  'deferred',
+  'do',
+  'dynamic',
+  'else',
+  'enum',
+  'export',
+  'extends',
+  'extension',
+  'external',
+  'factory',
+  'false',
+  'final',
+  'finally',
+  'for',
+  'Function',
+  'get',
+  'hide',
+  'if',
+  'implements',
+  'import',
+  'in',
+  'interface',
+  'is',
+  'late',
+  'library',
+  'mixin',
+  'new',
+  'null',
+  'on',
+  'operator',
+  'part',
+  'required',
+  'rethrow',
+  'return',
+  'set',
+  'show',
+  'static',
+  'super',
+  'switch',
+  'sync',
+  'this',
+  'throw',
+  'true',
+  'try',
+  'typedef',
+  'var',
+  'void',
+  'while',
+  'with',
+  'yield',
+};
+
 const bannedNames = <String>{
   'assert',
   'break',

web_generator/lib/src/cli.dart

@@ -14,7 +14,7 @@ import 'package:path/path.dart' as p;
 
 final bindingsGeneratorPath = p.fromUri(Platform.script.resolve('../lib/src'));
 
-Future<void> compileDartMain({String? langVersion}) async {
+Future<void> compileDartMain({String? langVersion, String? dir}) async {
   await runProc(
     Platform.executable,
     [
@@ -27,7 +27,7 @@ Future<void> compileDartMain({String? langVersion}) async {
       '-o',
       'dart_main.js',
     ],
-    workingDirectory: bindingsGeneratorPath,
+    workingDirectory: dir ?? bindingsGeneratorPath,
   );
 }
 

web_generator/lib/src/dart_main.dart

@@ -7,11 +7,12 @@ import 'dart:js_interop';
 import 'package:args/args.dart';
 import 'package:code_builder/code_builder.dart' as code;
 import 'package:dart_style/dart_style.dart';
+import 'package:path/path.dart' as p;
 import 'package:pub_semver/pub_semver.dart';
 
-import 'dts/parser.dart';
-import 'dts/transform.dart';
 import 'generate_bindings.dart';
+import 'interop_gen/parser.dart';
+import 'interop_gen/transform.dart';
 import 'js/filesystem_api.dart';
 import 'util.dart';
 
@@ -44,7 +45,7 @@ void main(List<String> args) async {
   }
 }
 
-// TODO(nikeokoronkwo): Add support for configuration
+// TODO(https://github.com/dart-lang/web/issues/376): Add support for configuration
 Future<void> generateJSInteropBindings({
   required Iterable<String> inputs,
   required String output,
@@ -54,13 +55,20 @@ Future<void> generateJSInteropBindings({
   final jsDeclarations = parseDeclarationFiles(inputs);
 
   // transform declarations
-  final dartDeclarations = transformDeclarations(jsDeclarations);
+  final dartDeclarations = transform(jsDeclarations);
 
   // generate
-  final generatedCode = dartDeclarations.generate();
-
-  // write code to file
-  fs.writeFileSync(output.toJS, generatedCode.toJS);
+  final generatedCodeMap = dartDeclarations.generate();
+
+  // write code to file(s)
+  if (inputs.length == 1) {
+    final singleEntry = generatedCodeMap.entries.single;
+    fs.writeFileSync(output.toJS, singleEntry.value.toJS);
+  } else {
+    for (final entry in generatedCodeMap.entries) {
+      fs.writeFileSync(p.join(output, entry.key).toJS, entry.value.toJS);
+    }
+  }
 }
 
 Future<void> generateIDLBindings({

web_generator/lib/src/dts/transform.dart → web_generator/lib/src/interop_gen/generate.dart

@@ -2,12 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
-class DeclarationMap {
-  String generate() {
-    throw UnimplementedError();
-  }
-}
+import 'package:code_builder/code_builder.dart';
 
-DeclarationMap transformDeclarations(Object? jsDeclarations) {
-  throw UnimplementedError();
+Expression generateJSAnnotation([String? name]) {
+  return refer('JS', 'dart:js_interop')
+      .call([if (name != null) literalString(name)]);
 }

web_generator/lib/src/interop_gen/namer.dart

@@ -0,0 +1,37 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+class ID {
+  final String type;
+  final String name;
+  final int? index;
+
+  const ID({required this.type, required this.name, this.index});
+
+  bool get isUnnamed => name == 'unnamed';
+
+  @override
+  String toString() => '$type#$name${index != null ? '#$index' : ''}';
+}
+
+class UniqueNamer {
+  final Set<String> _usedNames;
+
+  UniqueNamer([Iterable<String> used = const <String>[]])
+      : _usedNames = used.toSet();
+
+  static ID parse(String id) {
+    String? index;
+    final [type, name, ...ids] = id.split('#');
+    if (ids.isEmpty) index = ids.single;
+
+    return ID(
+        type: type, name: name, index: index == null ? null : int.parse(index));
+  }
+
+  /// Adds a [name] to used names.
+  void markUsed(String name) {
+    _usedNames.add(name);
+  }
+}

web_generator/lib/src/interop_gen/parser.dart

@@ -0,0 +1,21 @@
+// Copyright (c) 2025, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:js_interop';
+
+import '../js/typescript.dart' as ts;
+
+class ParserResult {
+  ts.TSProgram program;
+  Iterable<String> files;
+
+  ParserResult({required this.program, required this.files});
+}
+
+ParserResult parseDeclarationFiles(Iterable<String> files) {
+  final program = ts.createProgram(files.jsify() as JSArray<JSString>,
+      ts.TSCompilerOptions(declaration: true));
+
+  return ParserResult(program: program, files: files);
+}