blob: 5fdea077ce63818daf9ee0f51bc4165f06153153 [file] [log] [blame]
// Copyright (c) 2020, the Dart project authors. Please see the AUTHORS file
// for details. 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:analysis_server/src/services/correction/dart/abstract_producer.dart';
import 'package:analysis_server/src/services/correction/fix.dart';
import 'package:analyzer/dart/analysis/features.dart';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
class MakeReturnTypeNullable extends CorrectionProducer {
@override
FixKind get fixKind => DartFixKind.MAKE_RETURN_TYPE_NULLABLE;
@override
Future<void> compute(ChangeBuilder builder) async {
if (!unit.featureSet.isEnabled(Feature.non_nullable)) {
return;
}
if (node is! Expression) {
return;
}
var body = node.thisOrAncestorOfType<FunctionBody>();
TypeAnnotation returnType;
var function = body.parent;
if (function is FunctionExpression) {
function = function.parent;
}
if (function is MethodDeclaration) {
returnType = function.returnType;
} else if (function is FunctionDeclaration) {
returnType = function.returnType;
} else {
return;
}
if (body.isAsynchronous || body.isGenerator) {
if (returnType is! NamedType) {
return null;
}
var typeArguments = (returnType as NamedType).typeArguments;
if (typeArguments == null) {
return null;
}
var arguments = typeArguments.arguments;
if (arguments.length != 1) {
return null;
}
returnType = arguments[0];
}
if (node is! NullLiteral &&
!typeSystem.isAssignableTo(returnType.type,
typeSystem.promoteToNonNull((node as Expression).staticType))) {
return;
}
await builder.addDartFileEdit(file, (builder) {
builder.addSimpleInsertion(returnType.end, '?');
});
}
/// Return an instance of this class. Used as a tear-off in `FixProcessor`.
static MakeReturnTypeNullable newInstance() => MakeReturnTypeNullable();
}