pkg/analysis_server/lib/src/services/correction/dart/convert_to_normal_parameter.dart

// 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/assist.dart';
import 'package:analysis_server/src/services/correction/dart/abstract_producer.dart';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer_plugin/utilities/assist/assist.dart';
import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
import 'package:analyzer_plugin/utilities/range_factory.dart';

class ConvertToNormalParameter extends CorrectionProducer {
  @override
  AssistKind get assistKind => DartAssistKind.CONVERT_TO_NORMAL_PARAMETER;

  @override
  Future<void> compute(ChangeBuilder builder) async {
    if (node is SimpleIdentifier &&
        node.parent is FieldFormalParameter &&
        node.parent.parent is FormalParameterList &&
        node.parent.parent.parent is ConstructorDeclaration) {
      ConstructorDeclaration constructor = node.parent.parent.parent;
      FormalParameterList parameterList = node.parent.parent;
      FieldFormalParameter parameter = node.parent;
      var parameterElement = parameter.declaredElement;
      var name = (node as SimpleIdentifier).name;
      // prepare type
      var type = parameterElement.type;

      await builder.addDartFileEdit(file, (builder) {
        // replace parameter
        if (type.isDynamic) {
          builder.addSimpleReplacement(range.node(parameter), name);
        } else {
          builder.addReplacement(range.node(parameter), (builder) {
            builder.writeType(type);
            builder.write(' ');
            builder.write(name);
          });
        }
        // add field initializer
        List<ConstructorInitializer> initializers = constructor.initializers;
        if (initializers.isEmpty) {
          builder.addSimpleInsertion(parameterList.end, ' : $name = $name');
        } else {
          builder.addSimpleInsertion(initializers.last.end, ', $name = $name');
        }
      });
    }
  }

  /// Return an instance of this class. Used as a tear-off in `AssistProcessor`.
  static ConvertToNormalParameter newInstance() => ConvertToNormalParameter();
}