| // Copyright (c) 2016, 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:analyzer/dart/ast/ast.dart'; |
| import 'package:analyzer/dart/ast/visitor.dart'; |
| |
| import '../analyzer.dart'; |
| |
| const _desc = r'Avoid empty statements.'; |
| |
| const _details = r''' |
| |
| **AVOID** empty statements. |
| |
| Empty statements almost always indicate a bug. |
| |
| For example, |
| |
| **BAD:** |
| ``` |
| if (complicated.expression.foo()); |
| bar(); |
| ``` |
| |
| Formatted with `dartfmt` the bug becomes obvious: |
| |
| ``` |
| if (complicated.expression.foo()) ; |
| bar(); |
| |
| ``` |
| |
| Better to avoid the empty statement altogether. |
| |
| **GOOD:** |
| ``` |
| if (complicated.expression.foo()) |
| bar(); |
| ``` |
| |
| '''; |
| |
| class EmptyStatements extends LintRule implements NodeLintRule { |
| EmptyStatements() |
| : super( |
| name: 'empty_statements', |
| description: _desc, |
| details: _details, |
| group: Group.errors); |
| |
| @override |
| void registerNodeProcessors( |
| NodeLintRegistry registry, LinterContext context) { |
| final visitor = _Visitor(this); |
| registry.addEmptyStatement(this, visitor); |
| } |
| } |
| |
| class _Visitor extends SimpleAstVisitor<void> { |
| final LintRule rule; |
| |
| _Visitor(this.rule); |
| |
| @override |
| void visitEmptyStatement(EmptyStatement node) { |
| rule.reportLint(node); |
| } |
| } |