blob: 886c59902680baf0af30c4ef5a4fd9c1b7fa12d4 [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/assist.dart';
import 'package:analysis_server/src/services/correction/dart/abstract_producer.dart';
import 'package:analyzer/dart/ast/ast.dart';
import 'package:analyzer/dart/ast/visitor.dart';
import 'package:analyzer/dart/element/element.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 ConvertToFieldParameter extends CorrectionProducer {
@override
AssistKind get assistKind => DartAssistKind.CONVERT_TO_FIELD_PARAMETER;
@override
Future<void> compute(ChangeBuilder builder) async {
if (node == null) {
return;
}
// prepare ConstructorDeclaration
var constructor = node.thisOrAncestorOfType<ConstructorDeclaration>();
if (constructor == null) {
return;
}
var parameterList = constructor.parameters;
List<ConstructorInitializer> initializers = constructor.initializers;
// prepare parameter
SimpleFormalParameter parameter;
if (node.parent is SimpleFormalParameter &&
node.parent.parent is FormalParameterList &&
node.parent.parent.parent is ConstructorDeclaration) {
parameter = node.parent;
}
if (node is SimpleIdentifier &&
node.parent is ConstructorFieldInitializer) {
var name = (node as SimpleIdentifier).name;
ConstructorFieldInitializer initializer = node.parent;
if (initializer.expression == node) {
for (var formalParameter in parameterList.parameters) {
if (formalParameter is SimpleFormalParameter &&
formalParameter.identifier.name == name) {
parameter = formalParameter;
}
}
}
}
// analyze parameter
if (parameter != null) {
var parameterName = parameter.identifier.name;
var parameterElement = parameter.declaredElement;
// check number of references
var visitor = _ReferenceCounter(parameterElement);
for (var initializer in initializers) {
initializer.accept(visitor);
}
if (visitor.count != 1) {
return;
}
// find the field initializer
ConstructorFieldInitializer parameterInitializer;
for (var initializer in initializers) {
if (initializer is ConstructorFieldInitializer) {
var expression = initializer.expression;
if (expression is SimpleIdentifier &&
expression.name == parameterName) {
parameterInitializer = initializer;
}
}
}
if (parameterInitializer == null) {
return;
}
var fieldName = parameterInitializer.fieldName.name;
await builder.addDartFileEdit(file, (builder) {
// replace parameter
builder.addSimpleReplacement(range.node(parameter), 'this.$fieldName');
// remove initializer
var initializerIndex = initializers.indexOf(parameterInitializer);
if (initializers.length == 1) {
builder
.addDeletion(range.endEnd(parameterList, parameterInitializer));
} else {
if (initializerIndex == 0) {
var next = initializers[initializerIndex + 1];
builder.addDeletion(range.startStart(parameterInitializer, next));
} else {
var prev = initializers[initializerIndex - 1];
builder.addDeletion(range.endEnd(prev, parameterInitializer));
}
}
});
}
}
/// Return an instance of this class. Used as a tear-off in `AssistProcessor`.
static ConvertToFieldParameter newInstance() => ConvertToFieldParameter();
}
class _ReferenceCounter extends RecursiveAstVisitor<void> {
final ParameterElement parameterElement;
int count = 0;
_ReferenceCounter(this.parameterElement);
@override
void visitSimpleIdentifier(SimpleIdentifier node) {
if (node.staticElement == parameterElement) {
count++;
}
}
}