nits and error handling

packages/pigeon/lib/cpp_generator.dart

@@ -365,10 +365,8 @@ void _writeDataClassImplementation(Indent indent, Class klass, Root root) {
  // Deserialization.
  indent.write('${klass.name}::${klass.name}(flutter::EncodableList list) ');
  indent.scoped('{', '}', () {
- getFieldsInSerializationOrder(klass)
- .toList()
- .asMap()
- .forEach((int index, final NamedType field) {
+ enumerate(getFieldsInSerializationOrder(klass),
+ (int index, final NamedType field) {
  final String instanceVariableName = _makeInstanceVariableName(field);
  final String pointerFieldName =
  '${_pointerPrefix}_${_makeVariableName(field)}';
@@ -1061,12 +1059,10 @@ void generateCppHeader(
  indent, anEnum.documentationComments, _docCommentSpec);
  indent.write('enum class ${anEnum.name} ');
  indent.scoped('{', '};', () {
- int index = 0;
- for (final String member in anEnum.members) {
+ enumerate(anEnum.members, (int index, final String member) {
  indent.writeln(
  '$member = $index${index == anEnum.members.length - 1 ? '' : ','}');
- index++;
- }
+ });
  });
  }
 

packages/pigeon/lib/dart_generator.dart

@@ -78,10 +78,7 @@ void _writeCodec(Indent indent, String codecName, Api api, Root root) {
  indent.writeln('@override');
  indent.write('void writeValue(WriteBuffer buffer, Object? value) ');
  indent.scoped('{', '}', () {
- codecClasses
- .toList()
- .asMap()
- .forEach((int index, final EnumeratedClass customClass) {
+ enumerate(codecClasses, (int index, final EnumeratedClass customClass) {
  final String ifValue = 'if (value is ${customClass.name}) ';
  if (index == 0) {
  indent.write(ifValue);
@@ -169,7 +166,8 @@ String _getMethodArgumentsSignature(
 ///
 /// Messages will be sent and received in a list.
 ///
-/// If the message recieved was succesful it will be contained at the 0'th index.
+/// If the message recieved was succesful,
+/// the result will be contained at the 0'th index.
 ///
 /// If the message was a failure, the list will contain 3 items:
 /// a code, a message, and details in that order.
@@ -594,13 +592,12 @@ $resultAt != null
  indent.writeln('result as List<Object?>;');
  indent.write('return ${klass.name}');
  indent.scoped('(', ');', () {
- int index = 0;
- for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+ enumerate(getFieldsInSerializationOrder(klass),
+  (int index, final NamedType field) {
  indent.write('${field.name}: ');
  writeValueDecode(field, index);
  indent.addln(',');
- index++;
- }
+ });
  });
  });
  }

packages/pigeon/lib/java_generator.dart

@@ -290,9 +290,7 @@ Result<$returnType> $resultName = new Result<$returnType>() {
  if (method.isAsynchronous) {
  indent.writeln('reply.reply(wrappedError);');
  } else {
- indent.writeln('wrapped.add(wrappedError.get(0));');
- indent.writeln('wrapped.add(wrappedError.get(1));');
- indent.writeln('wrapped.add(wrappedError.get(2));');
+ indent.writeln('wrapped = wrappedError;');
  }
  });
  if (!method.isAsynchronous) {
@@ -571,17 +569,11 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
 
  indent.write('public enum ${anEnum.name} ');
  indent.scoped('{', '}', () {
- int index = 0;
- for (final String member in anEnum.members) {
+ enumerate(anEnum.members, (int index, final String member) {
  indent.writeln(
  '${camelToSnake(member)}($index)${index == anEnum.members.length - 1 ? ';' : ','}');
- index++;
- }
+ });
  indent.writeln('');
- // We use explicit indexing here as use of the ordinal() method is
- // discouraged. The toMap and fromMap API matches class API to allow
- // the same code to work with enums and classes, but this
- // can also be done directly in the host and flutter APIs.
  indent.writeln('private final int index;');
  indent.write('private ${anEnum.name}(final int index) ');
  indent.scoped('{', '}', () {
@@ -623,7 +615,7 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
  indent.write('@NonNull ArrayList<Object> toList() ');
  indent.scoped('{', '}', () {
  indent.writeln(
- 'ArrayList<Object> toListResult = new ArrayList<Object>();');
+ 'ArrayList<Object> toListResult = new ArrayList<Object>(${klass.fields.length});');
  for (final NamedType field in getFieldsInSerializationOrder(klass)) {
  final HostDatatype hostDatatype = getFieldHostDatatype(
  field,
@@ -653,10 +645,8 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
  indent.scoped('{', '}', () {
  const String result = 'pigeonResult';
  indent.writeln('${klass.name} $result = new ${klass.name}();');
- getFieldsInSerializationOrder(klass)
- .toList()
- .asMap()
- .forEach((int index, final NamedType field) {
+ enumerate(getFieldsInSerializationOrder(klass),
+ (int index, final NamedType field) {
  final String fieldVariable = field.name;
  final String setter = _makeSetter(field);
  indent.writeln('Object $fieldVariable = list.get($index);');
@@ -751,7 +741,7 @@ void generateJava(JavaOptions options, Root root, StringSink sink) {
  void writeWrapError() {
  indent.format('''
 @NonNull private static ArrayList<Object> wrapError(@NonNull Throwable exception) {
-\tArrayList<Object> errorList = new ArrayList<>();
+\tArrayList<Object> errorList = new ArrayList<>(3);
 \terrorList.add(exception.toString());
 \terrorList.add(exception.getClass().getSimpleName());
 \terrorList.add("Cause: " + exception.getCause() + ", Stacktrace: " + Log.getStackTraceString(exception));

packages/pigeon/lib/kotlin_generator.dart

@@ -214,7 +214,7 @@ void _writeHostApi(Indent indent, Api api, Root root) {
  indent.write('channel.setMessageHandler ');
  indent.scoped('{ $messageVarName, reply ->', '}', () {
  indent.writeln('val wrapped = mutableListOf<Any?>()');
-
+ indent.writeln('var error = listOf<Any?>()');
  indent.write('try ');
  indent.scoped('{', '}', () {
  final List<String> methodArgument = <String>[];
@@ -246,13 +246,20 @@ void _writeHostApi(Indent indent, Api api, Root root) {
  }, addTrailingNewline: false);
  indent.add(' catch (exception: Error) ');
  indent.scoped('{', '}', () {
- indent.writeln('wrapped.add(wrapError(exception))');
+ indent.writeln('error = wrapError(exception)');
  if (method.isAsynchronous) {
  indent.writeln('reply.reply(wrapped)');
  }
  });
  if (!method.isAsynchronous) {
- indent.writeln('reply.reply(wrapped)');
+ indent.write('if (error.size == 0) ');
+ indent.scoped('{', '}', () {
+ indent.writeln('reply.reply(wrapped)');
+ }, addTrailingNewline: false);
+ indent.add(' else ');
+ indent.scoped('{', '}', () {
+ indent.writeln('reply.reply(error)');
+ });
  }
  });
  }, addTrailingNewline: false);
@@ -472,20 +479,14 @@ void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
  indent, anEnum.documentationComments, _docCommentSpec);
  indent.write('enum class ${anEnum.name}(val raw: Int) ');
  indent.scoped('{', '}', () {
- // We use explicit indexing here as use of the ordinal() method is
- // discouraged. The toList and fromList API matches class API to allow
- // the same code to work with enums and classes, but this
- // can also be done directly in the host and flutter APIs.
- int index = 0;
- for (final String member in anEnum.members) {
+ enumerate(anEnum.members, (int index, final String member) {
  indent.write('${member.toUpperCase()}($index)');
  if (index != anEnum.members.length - 1) {
  indent.addln(',');
  } else {
  indent.addln(';');
  }
- index++;
- }
+ });
 
  indent.writeln('');
  indent.write('companion object ');
@@ -509,31 +510,26 @@ void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
  }
 
  void writeToList() {
- indent.write('fun toList(): MutableList<Any?> ');
+ indent.write('fun toList(): List<Any?> ');
  indent.scoped('{', '}', () {
- indent.writeln('val list = mutableListOf<Any?>()');
-
- for (final NamedType field in getFieldsInSerializationOrder(klass)) {
- final HostDatatype hostDatatype = getHostDatatype(field);
- String toWriteValue = '';
- final String fieldName = field.name;
- if (!hostDatatype.isBuiltin &&
- rootClassNameSet.contains(field.type.baseName)) {
- toWriteValue = '$fieldName?.toList()';
- } else if (!hostDatatype.isBuiltin &&
- rootEnumNameSet.contains(field.type.baseName)) {
- toWriteValue = '$fieldName?.raw';
- } else {
- toWriteValue = fieldName;
- }
-
- if (field.type.isNullable) {
- indent.writeln('list.add($toWriteValue)');
- } else {
- indent.writeln('list.add($toWriteValue)');
+ indent.write('return listOf<Any?>');
+ indent.scoped('(', ')', () {
+ for (final NamedType field in getFieldsInSerializationOrder(klass)) {
+ final HostDatatype hostDatatype = getHostDatatype(field);
+ String toWriteValue = '';
+ final String fieldName = field.name;
+ if (!hostDatatype.isBuiltin &&
+ rootClassNameSet.contains(field.type.baseName)) {
+ toWriteValue = '$fieldName?.toList()';
+ } else if (!hostDatatype.isBuiltin &&
+ rootEnumNameSet.contains(field.type.baseName)) {
+ toWriteValue = '$fieldName?.raw';
+ } else {
+ toWriteValue = fieldName;
+ }
+ indent.writeln('$toWriteValue,');
  }
- }
- indent.writeln('return list');
+ });
  });
  }
 
@@ -546,10 +542,8 @@ void generateKotlin(KotlinOptions options, Root root, StringSink sink) {
  indent.write('fun fromList(list: List<Any?>): $className ');
 
  indent.scoped('{', '}', () {
- getFieldsInSerializationOrder(klass)
- .toList()
- .asMap()
- .forEach((int index, final NamedType field) {
+ enumerate(getFieldsInSerializationOrder(klass),
+ (int index, final NamedType field) {
  final HostDatatype hostDatatype = getHostDatatype(field);
 
  // The StandardMessageCodec can give us [Integer, Long] for

packages/pigeon/lib/objc_generator.dart

@@ -561,13 +561,11 @@ void generateObjcHeader(ObjcOptions options, Root root, StringSink sink) {
 
  indent.write('typedef NS_ENUM(NSUInteger, $enumName) ');
  indent.scoped('{', '};', () {
- int index = 0;
- for (final String member in anEnum.members) {
+ enumerate(anEnum.members, (int index, final String member) {
  // Capitalized first letter to ensure Swift compatibility
  indent.writeln(
  '$enumName${member[0].toUpperCase()}${member.substring(1)} = $index,');
- index++;
- }
+ });
  });
  }
 
@@ -950,10 +948,8 @@ static id GetNullableObjectAtIndex(NSArray* array, NSInteger key) {
  indent.scoped('{', '}', () {
  const String resultName = 'pigeonResult';
  indent.writeln('$className *$resultName = [[$className alloc] init];');
- getFieldsInSerializationOrder(klass)
- .toList()
- .asMap()
- .forEach((int index, final NamedType field) {
+ enumerate(getFieldsInSerializationOrder(klass),
+ (int index, final NamedType field) {
  if (enumNames.contains(field.type.baseName)) {
  indent.writeln(
  '$resultName.${field.name} = [${_listGetter(classNames, 'list', field, index, options.prefix)} integerValue];');

packages/pigeon/lib/swift_generator.dart

@@ -470,15 +470,9 @@ import FlutterMacOS
 
  indent.write('enum ${anEnum.name}: Int ');
  indent.scoped('{', '}', () {
- // We use explicit indexing here as use of the ordinal() method is
- // discouraged. The toList and fromList API matches class API to allow
- // the same code to work with enums and classes, but this
- // can also be done directly in the host and flutter APIs.
- int index = 0;
- for (final String member in anEnum.members) {
+ enumerate(anEnum.members, (int index, final String member) {
  indent.writeln('case ${_camelCase(member)} = $index');
- index++;
- }
+ });
  });
  }
 
@@ -513,10 +507,7 @@ import FlutterMacOS
  toWriteValue = field.name;
  }
 
- final String comma =
- getFieldsInSerializationOrder(klass).last == field ? '' : ',';
-
- indent.writeln('$toWriteValue$comma');
+ indent.writeln('$toWriteValue,');
  }
  });
  });
@@ -527,10 +518,8 @@ import FlutterMacOS
  indent.write('static func fromList(_ list: [Any?]) -> $className? ');
 
  indent.scoped('{', '}', () {
- getFieldsInSerializationOrder(klass)
- .toList()
- .asMap()
- .forEach((int index, final NamedType field) {
+ enumerate(getFieldsInSerializationOrder(klass),
+ (int index, final NamedType field) {
  final HostDatatype hostDatatype = getHostDatatype(field);
 
  final String listValue = 'list[$index]';

packages/pigeon/test/kotlin_generator_test.dart

@@ -32,7 +32,7 @@ void main() {
  expect(code, contains('data class Foobar ('));
  expect(code, contains('val field1: Long? = null'));
  expect(code, contains('fun fromList(list: List<Any?>): Foobar'));
- expect(code, contains('fun toList(): MutableList<Any?>'));
+ expect(code, contains('fun toList(): List<Any?>'));
  });
 
  test('gen one enum', () {
@@ -130,14 +130,19 @@ void main() {
  if (api != null) {
  channel.setMessageHandler { message, reply ->
  val wrapped = mutableListOf<Any?>()
+ var error = listOf<Any?>()
  try {
  val args = message as List<Any?>
  val inputArg = args[0] as Input
  wrapped.add(api.doSomething(inputArg))
  } catch (exception: Error) {
- wrapped.add(wrapError(exception))
+ error = wrapError(exception)
+ }
+ if (error.size == 0) {
+ reply.reply(wrapped)
+ } else {
+ reply.reply(error)
  }
- reply.reply(wrapped)
  }
  } else {
  channel.setMessageHandler(null)
@@ -368,7 +373,7 @@ void main() {
  final String code = sink.toString();
  expect(code, contains('fun doSomething(): Output'));
  expect(code, contains('wrapped.add(api.doSomething())'));
- expect(code, contains('wrapped.add(wrapError(exception))'));
+ expect(code, contains('error = wrapError(exception)'));
  expect(code, contains('reply(wrapped)'));
  });
 
@@ -482,7 +487,7 @@ void main() {
  expect(
  code, contains('val nested: Nested? = (list[0] as? List<Any?>)?.let'));
  expect(code, contains('Nested.fromList(it)'));
- expect(code, contains('fun toList(): MutableList<Any?>'));
+ expect(code, contains('fun toList(): List<Any?>'));
  });
 
  test('gen one async Host Api', () {