[pigeon] Fixed decoding code for null-safe classes.

packages/pigeon/CHANGELOG.md

@@ -1,3 +1,8 @@
+## 0.1.21
+
+* Fixed decode method on generated Flutter classes that use null-safety and have
+  null values.
+
 ## 0.1.20
 
 * Implemented `@async` HostApi's for iOS.

packages/pigeon/lib/dart_generator.dart

@@ -178,11 +178,11 @@ void _writeFlutterApi(
 String _addGenericTypes(String dataType, String nullTag) {
   switch (dataType) {
     case 'List':
-      return 'List<Object$nullTag>';
+      return 'List<Object$nullTag>$nullTag';
     case 'Map':
-      return 'Map<Object$nullTag, Object$nullTag>';
+      return 'Map<Object$nullTag, Object$nullTag>$nullTag';
     default:
-      return dataType;
+      return '$dataType$nullTag';
   }
 }
 
@@ -211,8 +211,7 @@ void generateDart(DartOptions opt, Root root, StringSink sink) {
     sink.write('class ${klass.name} ');
     indent.scoped('{', '}', () {
       for (Field field in klass.fields) {
-        final String datatype =
-            '${_addGenericTypes(field.dataType, nullTag)}$nullTag';
+        final String datatype = '${_addGenericTypes(field.dataType, nullTag)}';
         indent.writeln('$datatype ${field.name};');
       }
       if (klass.fields.isNotEmpty) {

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 = '0.1.20';
+const String pigeonVersion = '0.1.21';
 
 /// Read all the content from [stdin] to a String.
 String readStdin() {

packages/pigeon/platform_tests/flutter_null_safe_unit_tests/.gitignore

@@ -0,0 +1,46 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.buildlog/
+.history
+.svn/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins
+.flutter-plugins-dependencies
+.packages
+.pub-cache/
+.pub/
+/build/
+
+# Web related
+lib/generated_plugin_registrant.dart
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release

packages/pigeon/platform_tests/flutter_null_safe_unit_tests/.metadata

@@ -0,0 +1,10 @@
+# This file tracks properties of this Flutter project.
+# Used by Flutter tool to assess capabilities and perform upgrades etc.
+#
+# This file should be version controlled and should not be manually edited.
+
+version:
+  revision: 6db3d61ed4a58ba89140d7fe1fd294b598cc29c5
+  channel: master
+
+project_type: app

packages/pigeon/platform_tests/flutter_null_safe_unit_tests/README.md

@@ -0,0 +1,3 @@
+# flutter_unit_tests
+
+Unit test scaffold for null safe Flutter projects.

packages/pigeon/platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart

@@ -0,0 +1,166 @@
+// Autogenerated from Pigeon (v0.1.21), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import
+// @dart = 2.12
+import 'dart:async';
+import 'dart:typed_data' show Uint8List, Int32List, Int64List, Float64List;
+
+import 'package:flutter/services.dart';
+
+class SearchReply {
+  String? result;
+  String? error;
+
+  Object encode() {
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
+    pigeonMap['result'] = result;
+    pigeonMap['error'] = error;
+    return pigeonMap;
+  }
+
+  static SearchReply decode(Object message) {
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
+    return SearchReply()
+      ..result = pigeonMap['result'] as String?
+      ..error = pigeonMap['error'] as String?;
+  }
+}
+
+class SearchRequest {
+  String? query;
+  int? anInt;
+  bool? aBool;
+
+  Object encode() {
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
+    pigeonMap['query'] = query;
+    pigeonMap['anInt'] = anInt;
+    pigeonMap['aBool'] = aBool;
+    return pigeonMap;
+  }
+
+  static SearchRequest decode(Object message) {
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
+    return SearchRequest()
+      ..query = pigeonMap['query'] as String?
+      ..anInt = pigeonMap['anInt'] as int?
+      ..aBool = pigeonMap['aBool'] as bool?;
+  }
+}
+
+class Nested {
+  SearchRequest? request;
+
+  Object encode() {
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
+    pigeonMap['request'] = request == null ? null : request!.encode();
+    return pigeonMap;
+  }
+
+  static Nested decode(Object message) {
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
+    return Nested()
+      ..request = pigeonMap['request'] != null
+          ? SearchRequest.decode(pigeonMap['request']!)
+          : null;
+  }
+}
+
+abstract class FlutterSearchApi {
+  SearchReply search(SearchRequest arg);
+  static void setup(FlutterSearchApi? api) {
+    {
+      const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+          'dev.flutter.pigeon.FlutterSearchApi.search', StandardMessageCodec());
+      if (api == null) {
+        channel.setMessageHandler(null);
+      } else {
+        channel.setMessageHandler((Object? message) async {
+          assert(message != null,
+              'Argument for dev.flutter.pigeon.FlutterSearchApi.search was null. Expected SearchRequest.');
+          final SearchRequest input = SearchRequest.decode(message!);
+          final SearchReply output = api.search(input);
+          return output.encode();
+        });
+      }
+    }
+  }
+}
+
+class NestedApi {
+  Future<SearchReply> search(Nested arg) async {
+    final Object encoded = arg.encode();
+    const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.NestedApi.search', StandardMessageCodec());
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(encoded) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+        details: null,
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          replyMap['error'] as Map<Object?, Object?>;
+      throw PlatformException(
+        code: error['code'] as String,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      return SearchReply.decode(replyMap['result']!);
+    }
+  }
+}
+
+class Api {
+  Future<void> initialize() async {
+    const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.Api.initialize', StandardMessageCodec());
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(null) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+        details: null,
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          replyMap['error'] as Map<Object?, Object?>;
+      throw PlatformException(
+        code: error['code'] as String,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      // noop
+    }
+  }
+
+  Future<SearchReply> search(SearchRequest arg) async {
+    final Object encoded = arg.encode();
+    const BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.Api.search', StandardMessageCodec());
+    final Map<Object?, Object?>? replyMap =
+        await channel.send(encoded) as Map<Object?, Object?>?;
+    if (replyMap == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+        details: null,
+      );
+    } else if (replyMap['error'] != null) {
+      final Map<Object?, Object?> error =
+          replyMap['error'] as Map<Object?, Object?>;
+      throw PlatformException(
+        code: error['code'] as String,
+        message: error['message'] as String?,
+        details: error['details'],
+      );
+    } else {
+      return SearchReply.decode(replyMap['result']!);
+    }
+  }
+}

packages/pigeon/platform_tests/flutter_null_safe_unit_tests/pubspec.yaml

@@ -0,0 +1,17 @@
+name: flutter_unit_tests
+description: Unit test scaffold for null safe Flutter projects.
+publish_to: 'none' # Remove this line if you wish to publish to pub.dev
+version: 1.0.0+1
+environment:
+  sdk: ">=2.12.0 <3.0.0"
+
+dependencies:
+  flutter:
+    sdk: flutter
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+
+flutter:
+  uses-material-design: true

packages/pigeon/platform_tests/flutter_null_safe_unit_tests/test/null_safe_test.dart

@@ -0,0 +1,28 @@
+// Copyright 2020 The Flutter Authors. 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:flutter_unit_tests/null_safe_pigeon.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('with values filled', () {
+    final SearchReply reply = SearchReply()
+      ..result = 'foo'
+      ..error = 'bar';
+    final Object encoded = reply.encode();
+    final SearchReply decoded = SearchReply.decode(encoded);
+    expect(reply.result, decoded.result);
+    expect(reply.error, decoded.error);
+  });
+
+  test('with null value', () {
+    final SearchReply reply = SearchReply()
+      ..result = 'foo'
+      ..error = null;
+    final Object encoded = reply.encode();
+    final SearchReply decoded = SearchReply.decode(encoded);
+    expect(reply.result, decoded.result);
+    expect(reply.error, decoded.error);
+  });
+}

packages/pigeon/pubspec.yaml

@@ -1,5 +1,5 @@
 name: pigeon
-version: 0.1.20 # This must match the version in lib/generator_tools.dart
+version: 0.1.21 # This must match the version in lib/generator_tools.dart
 description: Code generator tool to make communication between Flutter and the host platform type-safe and easier.
 homepage: https://github.com/flutter/packages/tree/master/packages/pigeon
 dependencies:

packages/pigeon/run_tests.sh

@@ -110,6 +110,19 @@ pub run test test/
 ###############################################################################
 pub run pigeon 1> /dev/null
 
+###############################################################################
+# Run unit tests on generated Dart code.
+###############################################################################
+pushd $PWD
+pub run pigeon \
+    --input pigeons/message.dart \
+    --dart_null_safety \
+    --dart_out platform_tests/flutter_null_safe_unit_tests/lib/null_safe_pigeon.dart
+cd platform_tests/flutter_null_safe_unit_tests
+flutter pub get
+flutter test test/null_safe_test.dart 
+popd
+
 ###############################################################################
 # Mock handler flutter tests.
 ###############################################################################