[pigeon] Minor fixes to NNBD type handling in Dart

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 3.0.2
+
+* Fixes non-nullable classes and enums as fields.
+* Fixes nullable collections as return types.
+
 ## 3.0.0
 
 * **BREAKING CHANGE**: Removes the `--dart_null_safety` flag. Generated Dart

packages/pigeon/lib/dart_generator.dart

@@ -192,7 +192,8 @@ final BinaryMessenger? _binaryMessenger;
         final String returnType = _makeGenericTypeArguments(func.returnType);
         final String castCall = _makeGenericCastCall(func.returnType);
         const String accessor = 'replyMap[\'${Keys.result}\']';
-        final String unwrapper = func.returnType.isNullable ? '' : '!';
+        final String unwrapper =
+            func.returnType.isNullable ? (castCall.isEmpty ? '' : '?') : '!';
         final String returnStatement = func.returnType.isVoid
             ? 'return;'
             : 'return ($accessor as $returnType?)$unwrapper$castCall;';
@@ -459,13 +460,14 @@ void generateDart(DartOptions opt, Root root, StringSink sink) {
         );
         for (final NamedType field in klass.fields) {
           indent.write('pigeonMap[\'${field.name}\'] = ');
+          final String conditional = field.type.isNullable ? '?' : '';
           if (customClassNames.contains(field.type.baseName)) {
             indent.addln(
-              '${field.name}?.encode();',
+              '${field.name}$conditional.encode();',
             );
           } else if (customEnumNames.contains(field.type.baseName)) {
             indent.addln(
-              '${field.name}?.index;',
+              '${field.name}$conditional.index;',
             );
           } else {
             indent.addln('${field.name};');
@@ -478,15 +480,29 @@ void generateDart(DartOptions opt, Root root, StringSink sink) {
     void writeDecode() {
       void writeValueDecode(NamedType field) {
         if (customClassNames.contains(field.type.baseName)) {
-          indent.format('''
+          final String nonNullValue =
+              "${field.type.baseName}.decode(pigeonMap['${field.name}']!)";
+          indent.format(
+              field.type.isNullable
+                  ? '''
 pigeonMap['${field.name}'] != null
-\t\t? ${field.type.baseName}.decode(pigeonMap['${field.name}']!)
-\t\t: null''', leadingSpace: false, trailingNewline: false);
+\t\t? $nonNullValue
+\t\t: null'''
+                  : nonNullValue,
+              leadingSpace: false,
+              trailingNewline: false);
         } else if (customEnumNames.contains(field.type.baseName)) {
-          indent.format('''
+          final String nonNullValue =
+              "${field.type.baseName}.values[pigeonMap['${field.name}']! as int]";
+          indent.format(
+              field.type.isNullable
+                  ? '''
 pigeonMap['${field.name}'] != null
-\t\t? ${field.type.baseName}.values[pigeonMap['${field.name}']! as int]
-\t\t: null''', leadingSpace: false, trailingNewline: false);
+\t\t? $nonNullValue
+\t\t: null'''
+                  : nonNullValue,
+              leadingSpace: false,
+              trailingNewline: false);
         } else if (field.type.typeArguments.isNotEmpty) {
           final String genericType = _makeGenericTypeArguments(field.type);
           final String castCall = _makeGenericCastCall(field.type);

packages/pigeon/lib/generator_tools.dart

@@ -8,7 +8,7 @@ import 'dart:mirrors';
 import 'ast.dart';
 
 /// The current version of pigeon. This must match the version in pubspec.yaml.
-const String pigeonVersion = '3.0.0';
+const String pigeonVersion = '3.0.2';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/pigeons/non_null_fields.dart

@@ -12,11 +12,21 @@ class SearchRequest {
   String query;
 }
 
+class ExtraData {
+  ExtraData({required this.detailA, required this.detailB});
+  String detailA;
+  String detailB;
+}
+
+enum ReplyType { success, error }
+
 class SearchReply {
-  SearchReply(this.result, this.error, this.indices);
+  SearchReply(this.result, this.error, this.indices, this.extraData, this.type);
   String result;
   String error;
   List<int?> indices;
+  ExtraData extraData;
+  ReplyType type;
 }
 
 @HostApi()

packages/pigeon/pigeons/nullable_returns.dart

@@ -26,3 +26,23 @@ abstract class NullableArgHostApi {
 abstract class NullableArgFlutterApi {
   int doit(int? x);
 }
+
+@HostApi()
+abstract class NonNullCollectionHostApi {
+  List<String?>? doit();
+}
+
+@FlutterApi()
+abstract class NonNullCollectionFlutterApi {
+  List<String?>? doit();
+}
+
+@HostApi()
+abstract class NullableCollectionArgHostApi {
+  List<String?> doit(List<String?>? x);
+}
+
+@FlutterApi()
+abstract class NullableCollectionArgFlutterApi {
+  List<String?> doit(List<String?>? x);
+}

packages/pigeon/pubspec.yaml

@@ -2,7 +2,7 @@ name: pigeon
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 repository: https://github.com/flutter/packages/tree/main/packages/pigeon
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3Apigeon
-version: 3.0.0 # This must match the version in lib/generator_tools.dart
+version: 3.0.2 # This must match the version in lib/generator_tools.dart
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

packages/pigeon/test/dart_generator_test.dart

@@ -204,6 +204,50 @@ void main() {
     );
   });
 
+  test('nested non-nullable class', () {
+    final Root root = Root(apis: <Api>[], classes: <Class>[
+      Class(
+        name: 'Input',
+        fields: <NamedType>[
+          NamedType(
+              type: const TypeDeclaration(
+                baseName: 'String',
+                isNullable: false,
+              ),
+              name: 'input',
+              offset: null)
+        ],
+      ),
+      Class(
+        name: 'Nested',
+        fields: <NamedType>[
+          NamedType(
+              type: const TypeDeclaration(
+                baseName: 'Input',
+                isNullable: false,
+              ),
+              name: 'nested',
+              offset: null)
+        ],
+      )
+    ], enums: <Enum>[]);
+    final StringBuffer sink = StringBuffer();
+    generateDart(const DartOptions(), root, sink);
+    final String code = sink.toString();
+    expect(
+      code,
+      contains(
+        'pigeonMap[\'nested\'] = nested.encode()',
+      ),
+    );
+    expect(
+      code.replaceAll('\n', ' ').replaceAll('  ', ''),
+      contains(
+        'nested: Input.decode(pigeonMap[\'nested\']!)',
+      ),
+    );
+  });
+
   test('flutterapi', () {
     final Root root = Root(apis: <Api>[
       Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
@@ -401,6 +445,51 @@ void main() {
     expect(code, contains('EnumClass doSomething(EnumClass arg0);'));
   });
 
+  test('flutter non-nullable enum argument with enum class', () {
+    final Root root = Root(apis: <Api>[
+      Api(name: 'Api', location: ApiLocation.flutter, methods: <Method>[
+        Method(
+          name: 'doSomething',
+          arguments: <NamedType>[
+            NamedType(
+                type: const TypeDeclaration(
+                  baseName: 'EnumClass',
+                  isNullable: false,
+                ),
+                name: '',
+                offset: null)
+          ],
+          returnType:
+              const TypeDeclaration(baseName: 'EnumClass', isNullable: false),
+          isAsynchronous: false,
+        )
+      ])
+    ], classes: <Class>[
+      Class(name: 'EnumClass', fields: <NamedType>[
+        NamedType(
+            type: const TypeDeclaration(
+              baseName: 'Enum',
+              isNullable: false,
+            ),
+            name: 'enum1',
+            offset: null)
+      ]),
+    ], enums: <Enum>[
+      Enum(
+        name: 'Enum',
+        members: <String>[
+          'one',
+          'two',
+        ],
+      )
+    ]);
+    final StringBuffer sink = StringBuffer();
+    generateDart(const DartOptions(), root, sink);
+    final String code = sink.toString();
+    expect(code, contains('pigeonMap[\'enum1\'] = enum1.index;'));
+    expect(code, contains('enum1: Enum.values[pigeonMap[\'enum1\']! as int]'));
+  });
+
   test('host void argument', () {
     final Root root = Root(apis: <Api>[
       Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
@@ -893,6 +982,34 @@ void main() {
     expect(code, contains('return (replyMap[\'result\'] as int?);'));
   });
 
+  test('return nullable collection host', () {
+    final Root root = Root(
+      apis: <Api>[
+        Api(name: 'Api', location: ApiLocation.host, methods: <Method>[
+          Method(
+              name: 'doit',
+              returnType: const TypeDeclaration(
+                  baseName: 'List',
+                  isNullable: true,
+                  typeArguments: <TypeDeclaration>[
+                    TypeDeclaration(baseName: 'int', isNullable: true)
+                  ]),
+              arguments: <NamedType>[])
+        ])
+      ],
+      classes: <Class>[],
+      enums: <Enum>[],
+    );
+    final StringBuffer sink = StringBuffer();
+    generateDart(const DartOptions(), root, sink);
+    final String code = sink.toString();
+    expect(code, contains('Future<List<int?>?> doit()'));
+    expect(
+        code,
+        contains(
+            'return (replyMap[\'result\'] as List<Object?>?)?.cast<int?>();'));
+  });
+
   test('return nullable async host', () {
     final Root root = Root(
       apis: <Api>[