[pigeon] unnamed arguments and nonnull typeArguments (#435)

2025-07-03 09:08:54 +08:00 · 2021-08-16 09:50:49 -07:00
parent 6304033742
commit 2c450d951b
9 changed files with 368 additions and 270 deletions
--- a/packages/pigeon/lib/ast.dart
+++ b/packages/pigeon/lib/ast.dart
@ -80,14 +80,14 @@ class TypeDeclaration {
  TypeDeclaration({
    required this.baseName,
    required this.isNullable,
-    this.typeArguments,
+    this.typeArguments = const <TypeDeclaration>[],
  });

  /// The base name of the [TypeDeclaration] (ex 'Foo' to 'Foo<Bar>?').
  final String baseName;

  /// The type arguments to the entity (ex 'Bar' to 'Foo<Bar>?').
-  final List<TypeDeclaration>? typeArguments;
+  final List<TypeDeclaration> typeArguments;

  /// True if the type is nullable.
  final bool isNullable;
--- a/packages/pigeon/lib/dart_generator.dart
+++ b/packages/pigeon/lib/dart_generator.dart
@ -94,16 +94,16 @@ void _writeCodec(Indent indent, String codecName, Api api) {

 /// Creates a Dart type where all type arguments are [Objects].
 String _makeGenericTypeArguments(TypeDeclaration type, String nullTag) {
-  return type.typeArguments != null
-      ? '${type.baseName}<${type.typeArguments!.map<String>((TypeDeclaration e) => 'Object$nullTag').join(', ')}>'
+  return type.typeArguments.isNotEmpty
+      ? '${type.baseName}<${type.typeArguments.map<String>((TypeDeclaration e) => 'Object$nullTag').join(', ')}>'
      : _addGenericTypes(type, nullTag);
 }

 /// Creates a `.cast<>` call for an type. Returns an empty string if the
 /// type has no type arguments.
 String _makeGenericCastCall(TypeDeclaration type, String nullTag) {
-  return type.typeArguments != null
-      ? '.cast<${_flattenTypeArguments(type.typeArguments!, nullTag)}>()'
+  return type.typeArguments.isNotEmpty
+      ? '.cast<${_flattenTypeArguments(type.typeArguments, nullTag)}>()'
      : '';
 }

@ -293,23 +293,23 @@ void _writeFlutterApi(
 /// used in Dart code.
 String _flattenTypeArguments(List<TypeDeclaration> args, String nullTag) {
  return args
-      .map<String>((TypeDeclaration arg) => arg.typeArguments == null
+      .map<String>((TypeDeclaration arg) => arg.typeArguments.isEmpty
          ? '${arg.baseName}$nullTag'
-          : '${arg.baseName}<${_flattenTypeArguments(arg.typeArguments!, nullTag)}>$nullTag')
+          : '${arg.baseName}<${_flattenTypeArguments(arg.typeArguments, nullTag)}>$nullTag')
      .join(', ');
 }

 /// Creates the type declaration for use in Dart code from a [NamedType] making sure
 /// that type arguments are used for primitive generic types.
 String _addGenericTypes(TypeDeclaration type, String nullTag) {
-  final List<TypeDeclaration>? typeArguments = type.typeArguments;
+  final List<TypeDeclaration> typeArguments = type.typeArguments;
  switch (type.baseName) {
    case 'List':
-      return (typeArguments == null)
+      return (typeArguments.isEmpty)
          ? 'List<Object$nullTag>'
          : 'List<${_flattenTypeArguments(typeArguments, nullTag)}>';
    case 'Map':
-      return (typeArguments == null)
+      return (typeArguments.isEmpty)
          ? 'Map<Object$nullTag, Object$nullTag>'
          : 'Map<${_flattenTypeArguments(typeArguments, nullTag)}>';
    default:
@ -412,7 +412,7 @@ pigeonMap['${field.name}'] != null
 pigeonMap['${field.name}'] != null
 \t\t? ${field.type.baseName}.values[pigeonMap['${field.name}']$unwrapOperator as int]
 \t\t: null''', leadingSpace: false, trailingNewline: false);
-            } else if (field.type.typeArguments != null) {
+            } else if (field.type.typeArguments.isNotEmpty) {
              final String genericType =
                  _makeGenericTypeArguments(field.type, nullTag);
              final String castCall = _makeGenericCastCall(field.type, nullTag);
--- a/packages/pigeon/lib/java_generator.dart
+++ b/packages/pigeon/lib/java_generator.dart
@ -305,10 +305,10 @@ String? _javaTypeForBuiltinDartType(TypeDeclaration type) {
  if (javaTypeForDartTypeMap.containsKey(type.baseName)) {
    return javaTypeForDartTypeMap[type.baseName];
  } else if (type.baseName == 'List') {
-    if (type.typeArguments == null) {
+    if (type.typeArguments.isEmpty) {
      return 'List<Object>';
    } else {
-      return 'List<${_flattenTypeArguments(type.typeArguments!)}>';
+      return 'List<${_flattenTypeArguments(type.typeArguments)}>';
    }
  } else {
    return null;
--- a/packages/pigeon/lib/objc_generator.dart
+++ b/packages/pigeon/lib/objc_generator.dart
@ -98,9 +98,9 @@ String? _objcTypePtrForPrimitiveDartType(String? classPrefix, NamedType field) {
 /// _objcTypeForDartType(null, 'int') => 'NSNumber'.
 String _objcTypeForDartType(String? classPrefix, TypeDeclaration field) {
  return _objcTypeForDartTypeMap.containsKey(field.baseName)
-      ? field.typeArguments == null
+      ? field.typeArguments.isEmpty
          ? _objcTypeForDartTypeMap[field.baseName]!
-          : '${_objcTypeForDartTypeMap[field.baseName]}<${_flattenTypeArguments(classPrefix, field.typeArguments!)}>'
+          : '${_objcTypeForDartTypeMap[field.baseName]}<${_flattenTypeArguments(classPrefix, field.typeArguments)}>'
      : _className(classPrefix, field.baseName);
 }

--- a/packages/pigeon/lib/pigeon_lib.dart
+++ b/packages/pigeon/lib/pigeon_lib.dart
@ -385,7 +385,7 @@ List<Error> _validateAst(Root root, String source) {
  for (final Class klass in root.classes) {
    for (final NamedType field in klass.fields) {
      if (field.type.typeArguments != null) {
-        for (final TypeDeclaration typeArgument in field.type.typeArguments!) {
+        for (final TypeDeclaration typeArgument in field.type.typeArguments) {
          if (!typeArgument.isNullable) {
            result.add(Error(
              message:
@ -443,6 +443,14 @@ List<Error> _validateAst(Root root, String source) {
          lineNumber: _calculateLineNumberNullable(source, method.offset),
        ));
      }
+      for (final NamedType unnamedType in method.arguments
+          .where((NamedType element) => element.type.baseName.isEmpty)) {
+        result.add(Error(
+          message:
+              'Arguments must specify their type in method "${method.name}" in API: "${api.name}"',
+          lineNumber: _calculateLineNumberNullable(source, unnamedType.offset),
+        ));
+      }
    }
  }

@ -648,20 +656,27 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
  }

  NamedType formalParameterToField(dart_ast.FormalParameter parameter) {
-    final dart_ast.TypeName typeName = parameter.childEntities.firstWhere(
-        (dart_ast_syntactic_entity.SyntacticEntity e) =>
-            e is dart_ast.TypeName) as dart_ast.TypeName;
-    final String argTypeBaseName = typeName.name.name;
-    final bool isNullable = typeName.question != null;
-    final List<TypeDeclaration>? argTypeArguments =
-        typeAnnotationsToTypeArguments(typeName.typeArguments);
-    return NamedType(
-        type: TypeDeclaration(
-            baseName: argTypeBaseName,
-            isNullable: isNullable,
-            typeArguments: argTypeArguments),
-        name: parameter.identifier?.name ?? '',
-        offset: null);
+    final dart_ast.TypeName? typeName =
+        getFirstChildOfType<dart_ast.TypeName>(parameter);
+    if (typeName != null) {
+      final String argTypeBaseName = typeName.name.name;
+      final bool isNullable = typeName.question != null;
+      final List<TypeDeclaration> argTypeArguments =
+          typeAnnotationsToTypeArguments(typeName.typeArguments);
+      return NamedType(
+          type: TypeDeclaration(
+              baseName: argTypeBaseName,
+              isNullable: isNullable,
+              typeArguments: argTypeArguments),
+          name: parameter.identifier?.name ?? '',
+          offset: parameter.offset);
+    } else {
+      return NamedType(
+        name: '',
+        type: TypeDeclaration(baseName: '', isNullable: false),
+        offset: parameter.offset,
+      );
+    }
  }

  static T? getFirstChildOfType<T>(dart_ast.AstNode entity) {
@ -716,13 +731,12 @@ class _RootBuilder extends dart_ast_visitor.RecursiveAstVisitor<Object?> {
    return null;
  }

-  List<TypeDeclaration>? typeAnnotationsToTypeArguments(
+  List<TypeDeclaration> typeAnnotationsToTypeArguments(
      dart_ast.TypeArgumentList? typeArguments) {
-    List<TypeDeclaration>? result;
+    final List<TypeDeclaration> result = <TypeDeclaration>[];
    if (typeArguments != null) {
      for (final Object x in typeArguments.childEntities) {
        if (x is dart_ast.TypeName) {
-          result ??= <TypeDeclaration>[];
          result.add(TypeDeclaration(
              baseName: x.name.name,
              isNullable: x.question != null,
--- a/packages/pigeon/test/dart_generator_test.dart
+++ b/packages/pigeon/test/dart_generator_test.dart
@ -14,7 +14,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'dataType1', isNullable: true, typeArguments: null),
+              baseName: 'dataType1',
+              isNullable: true,
+            ),
            name: 'field1',
            offset: null),
      ],
@ -60,7 +62,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: 'input',
                offset: null)
          ],
@ -72,14 +76,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -98,7 +106,9 @@ void main() {
        fields: <NamedType>[
          NamedType(
              type: TypeDeclaration(
-                  baseName: 'String', isNullable: true, typeArguments: null),
+                baseName: 'String',
+                isNullable: true,
+              ),
              name: 'input',
              offset: null)
        ],
@ -108,7 +118,9 @@ void main() {
        fields: <NamedType>[
          NamedType(
              type: TypeDeclaration(
-                  baseName: 'Input', isNullable: true, typeArguments: null),
+                baseName: 'Input',
+                isNullable: true,
+              ),
              name: 'nested',
              offset: null)
        ],
@ -139,7 +151,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: 'input',
                offset: null)
          ],
@ -151,14 +165,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -179,7 +197,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -191,7 +211,9 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
@ -211,7 +233,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -223,7 +247,9 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
@ -252,7 +278,9 @@ void main() {
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ]),
@ -272,9 +300,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'EnumClass',
-                    isNullable: false,
-                    typeArguments: null),
+                  baseName: 'EnumClass',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -286,7 +314,9 @@ void main() {
      Class(name: 'EnumClass', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Enum', isNullable: true, typeArguments: null),
+              baseName: 'Enum',
+              isNullable: true,
+            ),
            name: 'enum1',
            offset: null)
      ]),
@ -316,9 +346,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'EnumClass',
-                    isNullable: false,
-                    typeArguments: null),
+                  baseName: 'EnumClass',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -330,7 +360,9 @@ void main() {
      Class(name: 'EnumClass', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Enum', isNullable: true, typeArguments: null),
+              baseName: 'Enum',
+              isNullable: true,
+            ),
            name: 'enum1',
            offset: null)
      ]),
@ -368,7 +400,9 @@ void main() {
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ]),
@ -391,9 +425,9 @@ void main() {
              arguments: <NamedType>[
                NamedType(
                    type: TypeDeclaration(
-                        baseName: 'Input',
-                        isNullable: false,
-                        typeArguments: null),
+                      baseName: 'Input',
+                      isNullable: false,
+                    ),
                    name: '',
                    offset: null)
              ],
@ -406,9 +440,9 @@ void main() {
              arguments: <NamedType>[
                NamedType(
                    type: TypeDeclaration(
-                        baseName: 'Input',
-                        isNullable: false,
-                        typeArguments: null),
+                      baseName: 'Input',
+                      isNullable: false,
+                    ),
                    name: '',
                    offset: null)
              ],
@ -420,14 +454,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -459,7 +497,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'dataType1', isNullable: true, typeArguments: null),
+              baseName: 'dataType1',
+              isNullable: true,
+            ),
            name: 'field1',
            offset: null),
      ],
@ -483,7 +523,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -495,14 +537,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -524,7 +570,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -536,14 +584,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -564,7 +616,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -576,14 +630,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -609,7 +667,9 @@ void main() {
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ]),
--- a/packages/pigeon/test/java_generator_test.dart
+++ b/packages/pigeon/test/java_generator_test.dart
@ -13,7 +13,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'int', isNullable: true, typeArguments: null),
+              baseName: 'int',
+              isNullable: true,
+            ),
            name: 'field1',
            offset: null),
      ],
@ -63,7 +65,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'int', isNullable: true, typeArguments: null),
+              baseName: 'int',
+              isNullable: true,
+            ),
            name: 'field1',
            offset: null)
      ],
@ -90,7 +94,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -102,14 +108,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -128,42 +138,58 @@ void main() {
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'bool', isNullable: true, typeArguments: null),
+              baseName: 'bool',
+              isNullable: true,
+            ),
            name: 'aBool',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'int', isNullable: true, typeArguments: null),
+              baseName: 'int',
+              isNullable: true,
+            ),
            name: 'aInt',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'double', isNullable: true, typeArguments: null),
+              baseName: 'double',
+              isNullable: true,
+            ),
            name: 'aDouble',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'aString',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Uint8List', isNullable: true, typeArguments: null),
+              baseName: 'Uint8List',
+              isNullable: true,
+            ),
            name: 'aUint8List',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Int32List', isNullable: true, typeArguments: null),
+              baseName: 'Int32List',
+              isNullable: true,
+            ),
            name: 'aInt32List',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Int64List', isNullable: true, typeArguments: null),
+              baseName: 'Int64List',
+              isNullable: true,
+            ),
            name: 'aInt64List',
            offset: null),
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Float64List', isNullable: true, typeArguments: null),
+              baseName: 'Float64List',
+              isNullable: true,
+            ),
            name: 'aFloat64List',
            offset: null),
      ]),
@ -191,7 +217,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -203,14 +231,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -231,7 +263,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -243,7 +277,9 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
@ -264,7 +300,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -276,7 +314,9 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
@ -303,7 +343,9 @@ void main() {
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ]),
@ -330,7 +372,9 @@ void main() {
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ]),
@ -348,7 +392,9 @@ void main() {
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'List', isNullable: true, typeArguments: null),
+              baseName: 'List',
+              isNullable: true,
+            ),
            name: 'field1',
            offset: null)
      ]),
@ -366,7 +412,9 @@ void main() {
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Map', isNullable: true, typeArguments: null),
+              baseName: 'Map',
+              isNullable: true,
+            ),
            name: 'field1',
            offset: null)
      ]),
@ -385,7 +433,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Nested', isNullable: true, typeArguments: null),
+              baseName: 'Nested',
+              isNullable: true,
+            ),
            name: 'nested',
            offset: null)
      ],
@ -395,7 +445,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'int', isNullable: true, typeArguments: null),
+              baseName: 'int',
+              isNullable: true,
+            ),
            name: 'data',
            offset: null)
      ],
@ -426,7 +478,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: 'arg',
                offset: null)
          ],
@ -438,14 +492,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -473,7 +531,9 @@ void main() {
          arguments: <NamedType>[
            NamedType(
                type: TypeDeclaration(
-                    baseName: 'Input', isNullable: false, typeArguments: null),
+                  baseName: 'Input',
+                  isNullable: false,
+                ),
                name: '',
                offset: null)
          ],
@ -485,14 +545,18 @@ void main() {
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+              baseName: 'String',
+              isNullable: true,
+            ),
            name: 'output',
            offset: null)
      ])
@ -518,7 +582,9 @@ void main() {
      fields: <NamedType>[
        NamedType(
            type: TypeDeclaration(
-                baseName: 'Enum1', isNullable: true, typeArguments: null),
+              baseName: 'Enum1',
+              isNullable: true,
+            ),
            name: 'enum1',
            offset: null),
      ],
--- a/packages/pigeon/test/objc_generator_test.dart
+++ b/packages/pigeon/test/objc_generator_test.dart
@ -11,8 +11,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'field1',
            offset: null)
      ]),
@ -28,8 +27,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'field1',
            offset: null)
      ]),
@ -85,13 +83,11 @@ void main() {
          name: 'Foobar',
          fields: <NamedType>[
            NamedType(
-                type: TypeDeclaration(
-                    baseName: 'String', isNullable: true, typeArguments: null),
+                type: TypeDeclaration(baseName: 'String', isNullable: true),
                name: 'field1',
                offset: null),
            NamedType(
-                type: TypeDeclaration(
-                    baseName: 'Enum1', isNullable: true, typeArguments: null),
+                type: TypeDeclaration(baseName: 'Enum1', isNullable: true),
                name: 'enum1',
                offset: null),
          ],
@ -123,13 +119,11 @@ void main() {
          name: 'Foobar',
          fields: <NamedType>[
            NamedType(
-                type: TypeDeclaration(
-                    baseName: 'String', isNullable: true, typeArguments: null),
+                type: TypeDeclaration(baseName: 'String', isNullable: true),
                name: 'field1',
                offset: null),
            NamedType(
-                type: TypeDeclaration(
-                    baseName: 'Enum1', isNullable: true, typeArguments: null),
+                type: TypeDeclaration(baseName: 'Enum1', isNullable: true),
                name: 'enum1',
                offset: null),
          ],
@ -158,10 +152,7 @@ void main() {
            name: 'doSomething',
            arguments: <NamedType>[
              NamedType(
-                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                  type: TypeDeclaration(baseName: 'Input', isNullable: false),
                  name: '',
                  offset: null)
            ],
@ -170,15 +161,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ])
@ -201,9 +190,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -212,15 +201,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ])
@ -238,43 +225,35 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'bool', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'bool', isNullable: true),
            name: 'aBool',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'int', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'int', isNullable: true),
            name: 'aInt',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'double', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'double', isNullable: true),
            name: 'aDouble',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'aString',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Uint8List', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Uint8List', isNullable: true),
            name: 'aUint8List',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Int32List', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Int32List', isNullable: true),
            name: 'aInt32List',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Int64List', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Int64List', isNullable: true),
            name: 'aInt64List',
            offset: null),
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Float64List', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Float64List', isNullable: true),
            name: 'aFloat64List',
            offset: null),
      ]),
@ -303,8 +282,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'bool', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'bool', isNullable: true),
            name: 'aBool',
            offset: null),
      ]),
@ -321,15 +299,13 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Nested', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Input', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Input', isNullable: true),
            name: 'nested',
            offset: null)
      ])
@ -345,15 +321,13 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Nested', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Input', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Input', isNullable: true),
            name: 'nested',
            offset: null)
      ])
@ -369,8 +343,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'field1',
            offset: null)
      ]),
@ -385,8 +358,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'field1',
            offset: null)
      ]),
@ -405,9 +377,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -416,15 +388,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Nested', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Input', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Input', isNullable: true),
            name: 'nested',
            offset: null)
      ])
@ -445,9 +415,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -456,15 +426,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Nested', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Input', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Input', isNullable: true),
            name: 'nested',
            offset: null)
      ])
@ -485,9 +453,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -496,15 +464,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ])
@ -528,9 +494,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -539,15 +505,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ])
@ -567,9 +531,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -578,8 +542,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
@ -599,9 +562,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -610,8 +573,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
@ -633,9 +595,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -644,8 +606,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
@ -665,9 +626,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -676,8 +637,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
@ -701,8 +661,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -725,8 +684,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -749,8 +707,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -776,8 +733,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -797,8 +753,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'List', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'List', isNullable: true),
            name: 'field1',
            offset: null)
      ]),
@ -814,8 +769,7 @@ void main() {
    final Root root = Root(apis: <Api>[], classes: <Class>[
      Class(name: 'Foobar', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'Map', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'Map', isNullable: true),
            name: 'field1',
            offset: null)
      ]),
@ -835,9 +789,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -847,15 +801,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -878,9 +830,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -890,15 +842,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -925,8 +875,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -969,9 +918,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -981,15 +930,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -1012,9 +959,9 @@ void main() {
            arguments: <NamedType>[
              NamedType(
                  type: TypeDeclaration(
-                      baseName: 'Input',
-                      isNullable: false,
-                      typeArguments: null),
+                    baseName: 'Input',
+                    isNullable: false,
+                  ),
                  name: '',
                  offset: null)
            ],
@ -1024,15 +971,13 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Input', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'input',
            offset: null)
      ]),
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
@ -1077,8 +1022,7 @@ void main() {
    ], classes: <Class>[
      Class(name: 'Output', fields: <NamedType>[
        NamedType(
-            type: TypeDeclaration(
-                baseName: 'String', isNullable: true, typeArguments: null),
+            type: TypeDeclaration(baseName: 'String', isNullable: true),
            name: 'output',
            offset: null)
      ]),
--- a/packages/pigeon/test/pigeon_lib_test.dart
+++ b/packages/pigeon/test/pigeon_lib_test.dart
@ -577,8 +577,8 @@ abstract class Api {
    final ParseResults parseResult = _parseSource(code);
    expect(parseResult.errors.length, equals(0));
    final NamedType field = parseResult.root.classes[0].fields[0];
-    expect(field.type.typeArguments!.length, 1);
-    expect(field.type.typeArguments![0].baseName, 'int');
+    expect(field.type.typeArguments.length, 1);
+    expect(field.type.typeArguments[0].baseName, 'int');
  });

  test('parse recursive generics', () {
@ -595,9 +595,9 @@ abstract class Api {
    final ParseResults parseResult = _parseSource(code);
    expect(parseResult.errors.length, equals(0));
    final NamedType field = parseResult.root.classes[0].fields[0];
-    expect(field.type.typeArguments!.length, 1);
-    expect(field.type.typeArguments![0].baseName, 'List');
-    expect(field.type.typeArguments![0].typeArguments![0].baseName, 'int');
+    expect(field.type.typeArguments.length, 1);
+    expect(field.type.typeArguments[0].baseName, 'List');
+    expect(field.type.typeArguments[0].typeArguments[0].baseName, 'int');
  });

  test('error nonnull type argument', () {
@ -668,11 +668,11 @@ abstract class Api {
    expect(parseResult.root.apis[0].methods[0].returnType.baseName, 'List');
    expect(
        parseResult
-            .root.apis[0].methods[0].returnType.typeArguments![0].baseName,
+            .root.apis[0].methods[0].returnType.typeArguments[0].baseName,
        'double');
    expect(
        parseResult
-            .root.apis[0].methods[0].returnType.typeArguments![0].isNullable,
+            .root.apis[0].methods[0].returnType.typeArguments[0].isNullable,
        isTrue);
  });

@ -687,11 +687,11 @@ abstract class Api {
    expect(
        parseResult.root.apis[0].methods[0].arguments[0].type.baseName, 'List');
    expect(
-        parseResult.root.apis[0].methods[0].arguments[0].type.typeArguments![0]
+        parseResult.root.apis[0].methods[0].arguments[0].type.typeArguments[0]
            .baseName,
        'double');
    expect(
-        parseResult.root.apis[0].methods[0].arguments[0].type.typeArguments![0]
+        parseResult.root.apis[0].methods[0].arguments[0].type.typeArguments[0]
            .isNullable,
        isTrue);
  });
@ -709,9 +709,9 @@ abstract class Api {
 ''';
    final ParseResults parseResult = _parseSource(code);
    final NamedType field = parseResult.root.classes[0].fields[0];
-    expect(field.type.typeArguments!.length, 2);
-    expect(field.type.typeArguments![0].baseName, 'String');
-    expect(field.type.typeArguments![1].baseName, 'int');
+    expect(field.type.typeArguments.length, 2);
+    expect(field.type.typeArguments[0].baseName, 'String');
+    expect(field.type.typeArguments[1].baseName, 'int');
  });

  test('two arguments', () {
@ -735,4 +735,18 @@ abstract class Api {
    // expect(results.root.apis[0].methods[0].name, equals('method'));
    // expect(results.root.apis[0].methods[0].arguments.length, 2);
  });
+
+  test('no type name argument', () {
+    const String code = '''
+@HostApi()
+abstract class Api {
+  void method(x);
+}
+''';
+    final ParseResults results = _parseSource(code);
+    expect(results.errors.length, 1);
+    expect(results.errors[0].lineNumber, 3);
+    expect(results.errors[0].message,
+        contains('Arguments must specify their type'));
+  });
 }