[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

@@ -192,10 +192,11 @@ final BinaryMessenger? _binaryMessenger;
         final String returnType = _makeGenericTypeArguments(func.returnType);
         final String castCall = _makeGenericCastCall(func.returnType);
         const String accessor = 'replyMap[\'${Keys.result}\']';
-        final String unwrapper = func.returnType.isNullable ? '' : '!';
+        final String nullHandler =
+            func.returnType.isNullable ? (castCall.isEmpty ? '' : '?') : '!';
         final String returnStatement = func.returnType.isVoid
             ? 'return;'
-            : 'return ($accessor as $returnType?)$unwrapper$castCall;';
+            : 'return ($accessor as $returnType?)$nullHandler$castCall;';
         indent.format('''
 final Map<Object?, Object?>? replyMap =\n\t\tawait channel.send($sendArgument) as Map<Object?, Object?>?;
 if (replyMap == null) {
@@ -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

@@ -8,12 +8,12 @@
 import 'package:pigeon/pigeon.dart';
 
 @HostApi()
-abstract class NonNullHostApi {
+abstract class NullableReturnHostApi {
   int? doit();
 }
 
 @FlutterApi()
-abstract class NonNullFlutterApi {
+abstract class NullableReturnFlutterApi {
   int? doit();
 }
 
@@ -26,3 +26,23 @@ abstract class NullableArgHostApi {
 abstract class NullableArgFlutterApi {
   int doit(int? x);
 }
+
+@HostApi()
+abstract class NullableCollectionReturnHostApi {
+  List<String?>? doit();
+}
+
+@FlutterApi()
+abstract class NullableCollectionReturnFlutterApi {
+  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/platform_tests/flutter_null_safe_unit_tests/lib/non_null_fields.gen.dart

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
-// Autogenerated from Pigeon (v2.0.4), do not edit directly.
+// Autogenerated from Pigeon (v3.0.2), 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, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name
 // @dart = 2.12
@@ -12,6 +12,11 @@ import 'dart:typed_data' show Uint8List, Int32List, Int64List, Float64List;
 import 'package:flutter/foundation.dart' show WriteBuffer, ReadBuffer;
 import 'package:flutter/services.dart';
 
+enum ReplyType {
+  success,
+  error,
+}
+
 class SearchRequest {
   SearchRequest({
     required this.query,
@@ -33,22 +38,53 @@ class SearchRequest {
   }
 }
 
+class ExtraData {
+  ExtraData({
+    required this.detailA,
+    required this.detailB,
+  });
+
+  String detailA;
+  String detailB;
+
+  Object encode() {
+    final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
+    pigeonMap['detailA'] = detailA;
+    pigeonMap['detailB'] = detailB;
+    return pigeonMap;
+  }
+
+  static ExtraData decode(Object message) {
+    final Map<Object?, Object?> pigeonMap = message as Map<Object?, Object?>;
+    return ExtraData(
+      detailA: pigeonMap['detailA']! as String,
+      detailB: pigeonMap['detailB']! as String,
+    );
+  }
+}
+
 class SearchReply {
   SearchReply({
     required this.result,
     required this.error,
     required this.indices,
+    required this.extraData,
+    required this.type,
   });
 
   String result;
   String error;
   List<int?> indices;
+  ExtraData extraData;
+  ReplyType type;
 
   Object encode() {
     final Map<Object?, Object?> pigeonMap = <Object?, Object?>{};
     pigeonMap['result'] = result;
     pigeonMap['error'] = error;
     pigeonMap['indices'] = indices;
+    pigeonMap['extraData'] = extraData.encode();
+    pigeonMap['type'] = type.index;
     return pigeonMap;
   }
 
@@ -58,6 +94,8 @@ class SearchReply {
       result: pigeonMap['result']! as String,
       error: pigeonMap['error']! as String,
       indices: (pigeonMap['indices'] as List<Object?>?)!.cast<int?>(),
+      extraData: ExtraData.decode(pigeonMap['extraData']!),
+      type: ReplyType.values[pigeonMap['type']! as int],
     );
   }
 }
@@ -66,12 +104,15 @@ class _NonNullHostApiCodec extends StandardMessageCodec {
   const _NonNullHostApiCodec();
   @override
   void writeValue(WriteBuffer buffer, Object? value) {
-    if (value is SearchReply) {
+    if (value is ExtraData) {
       buffer.putUint8(128);
       writeValue(buffer, value.encode());
-    } else if (value is SearchRequest) {
+    } else if (value is SearchReply) {
       buffer.putUint8(129);
       writeValue(buffer, value.encode());
+    } else if (value is SearchRequest) {
+      buffer.putUint8(130);
+      writeValue(buffer, value.encode());
     } else {
       super.writeValue(buffer, value);
     }
@@ -81,9 +122,12 @@ class _NonNullHostApiCodec extends StandardMessageCodec {
   Object? readValueOfType(int type, ReadBuffer buffer) {
     switch (type) {
       case 128:
-        return SearchReply.decode(readValue(buffer)!);
+        return ExtraData.decode(readValue(buffer)!);
 
       case 129:
+        return SearchReply.decode(readValue(buffer)!);
+
+      case 130:
         return SearchRequest.decode(readValue(buffer)!);
 
       default:
@@ -137,12 +181,15 @@ class _NonNullFlutterApiCodec extends StandardMessageCodec {
   const _NonNullFlutterApiCodec();
   @override
   void writeValue(WriteBuffer buffer, Object? value) {
-    if (value is SearchReply) {
+    if (value is ExtraData) {
       buffer.putUint8(128);
       writeValue(buffer, value.encode());
-    } else if (value is SearchRequest) {
+    } else if (value is SearchReply) {
       buffer.putUint8(129);
       writeValue(buffer, value.encode());
+    } else if (value is SearchRequest) {
+      buffer.putUint8(130);
+      writeValue(buffer, value.encode());
     } else {
       super.writeValue(buffer, value);
     }
@@ -152,9 +199,12 @@ class _NonNullFlutterApiCodec extends StandardMessageCodec {
   Object? readValueOfType(int type, ReadBuffer buffer) {
     switch (type) {
       case 128:
-        return SearchReply.decode(readValue(buffer)!);
+        return ExtraData.decode(readValue(buffer)!);
 
       case 129:
+        return SearchReply.decode(readValue(buffer)!);
+
+      case 130:
         return SearchRequest.decode(readValue(buffer)!);
 
       default: