feat: Prefer correct identifier length (#494)

* Prefer correct identifier name

* Added rule to rules factory

* Review changes

* feat: formatted code

* feat: moved creating validator in rule constructor

* feat: moved validator file

* feat: sorted alphabetical

* fix: changed test case

* Update lib/src/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/utils/config_parser.dart

Co-authored-by: Denis Grafov <grafov.denis@gmail.com>

* fix: Den review changes

* fix: Add getter and setter lint. Ignore _ in variable name

* fix: Analised issue

* fix: CHANGELOG.md

* fix: formatted code

* Update lib/src/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/prefer_correct_identifier_length.dart

Co-authored-by: Denis Grafov <grafov.denis@gmail.com>

* fix: change error label

* Update CHANGELOG.md

Co-authored-by: Denis Grafov <grafov.denis@gmail.com>

* fix: change reduce -> decrease

* fix: change reduce -> decrease

* fix: change reduce -> decrease

* fix: change reduce -> decrease

* fix: change reduce -> decrease

* check const and global variable

* convert to normal function

* add examples and support enums

* Review changes

* Add lint comments

Co-authored-by: Denis Grafov <grafov.denis@gmail.com>
Co-authored-by: Dmitry Krutskikh <dmitry.krutskikh@gmail.com>

Author: 3 people

CHANGELOG.md

@@ -5,6 +5,7 @@
 * chore: changed min `SDK` version to `2.14.0`.
 * chore: restrict `analyzer` version to `>=2.4.0 <2.6.0`.
 * chore: changed the supported `analyzer_plugin` version to `^0.8.0`.
+* feat: add static code diagnostic `prefer-correct-identifier-length`.
 
 ## 4.4.0
 

lib/src/analyzers/lint_analyzer/rules/rules_factory.dart

@@ -22,6 +22,7 @@ import 'rules_list/no_magic_number/no_magic_number.dart';
 import 'rules_list/no_object_declaration/no_object_declaration.dart';
 import 'rules_list/prefer_conditional_expressions/prefer_conditional_expressions.dart';
 import 'rules_list/prefer_const_border_radius/prefer_const_border_radius.dart';
+import 'rules_list/prefer_correct_identifier_length/prefer_correct_identifier_length.dart';
 import 'rules_list/prefer_extracting_callbacks/prefer_extracting_callbacks.dart';
 import 'rules_list/prefer_intl_name/prefer_intl_name.dart';
 import 'rules_list/prefer_match_file_name/prefer_match_file_name.dart';
@@ -67,6 +68,8 @@ final _implementedRules = <String, Rule Function(Map<String, Object>)>{
       PreferConditionalExpressionsRule(config),
   PreferConstBorderRadiusRule.ruleId: (config) =>
       PreferConstBorderRadiusRule(config),
+  PreferCorrectIdentifierLength.ruleId: (config) =>
+      PreferCorrectIdentifierLength(config),
   PreferExtractingCallbacksRule.ruleId: (config) =>
       PreferExtractingCallbacksRule(config),
   PreferIntlNameRule.ruleId: (config) => PreferIntlNameRule(config),

lib/src/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/prefer_correct_identifier_length.dart

@@ -0,0 +1,59 @@
+import 'package:analyzer/dart/ast/ast.dart';
+
+import '../../../../../utils/node_utils.dart';
+import '../../../lint_utils.dart';
+import '../../../metrics/scope_visitor.dart';
+import '../../../models/internal_resolved_unit_result.dart';
+import '../../../models/issue.dart';
+import '../../../models/severity.dart';
+import '../../models/common_rule.dart';
+import '../../models/rule_documentation.dart';
+import '../../rule_utils.dart';
+
+part 'utils/config_parser.dart';
+
+part 'validator.dart';
+
+part 'visitor.dart';
+
+class PreferCorrectIdentifierLength extends CommonRule {
+  static const String ruleId = 'prefer-correct-identifier-length';
+  final _Validator _validator;
+
+  PreferCorrectIdentifierLength([Map<String, Object> config = const {}])
+      : _validator = _Validator(
+          _ConfigParser.readMaxIdentifierLength(config),
+          _ConfigParser.readMinIdentifierLength(config),
+          _ConfigParser.readExceptions(config),
+        ),
+        super(
+          id: ruleId,
+          documentation: const RuleDocumentation(
+            name: 'Prefer correct identifier length',
+            brief: 'Warns when identifier name length very short or long.',
+          ),
+          severity: readSeverity(config, Severity.style),
+          excludes: readExcludes(config),
+        );
+
+  @override
+  Iterable<Issue> check(InternalResolvedUnitResult source) {
+    final visitor = _Visitor(_validator);
+
+    source.unit.visitChildren(visitor);
+
+    return visitor.nodes
+        .map(
+          (node) => createIssue(
+            rule: this,
+            location: nodeLocation(node: node, source: source),
+            message: createErrorMessage(node.name),
+          ),
+        )
+        .toList(growable: false);
+  }
+
+  String createErrorMessage(String name) => name.length > _validator.maxLength
+      ? "The $name identifier is ${name.length} characters long. It's recommended to decrease it to ${_validator.maxLength} chars long."
+      : "The $name identifier is ${name.length} characters long. It's recommended to increase it up to ${_validator.minLength} chars long.";
+}

lib/src/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/utils/config_parser.dart

@@ -0,0 +1,34 @@
+part of '../prefer_correct_identifier_length.dart';
+
+const _defaultMinIdentifierLength = 3;
+const _defaultMaxIdentifierLength = 300;
+const _defaultExceptions = <String>[];
+
+const _minIdentifierLengthLabel = 'min-identifier-length';
+const _maxIdentifierLengthLabel = 'max-identifier-length';
+const _exceptionsLabel = 'exceptions';
+
+/// Parser for rule configuration
+class _ConfigParser {
+  /// Read min identifier length from config
+  static int readMinIdentifierLength(Map<String, Object> config) =>
+      _parseIntConfig(config[_minIdentifierLengthLabel]) ??
+      _defaultMinIdentifierLength;
+
+  /// Read max identifier length from config
+  static int readMaxIdentifierLength(Map<String, Object> config) =>
+      _parseIntConfig(config[_maxIdentifierLengthLabel]) ??
+      _defaultMaxIdentifierLength;
+
+  /// Read exceptions list from config
+  static Iterable<String> readExceptions(Map<String, Object> config) =>
+      _isIterableOfStrings(config[_exceptionsLabel])
+          ? (config[_exceptionsLabel] as Iterable).cast<String>()
+          : _defaultExceptions;
+
+  static int? _parseIntConfig(Object? value) =>
+      value != null ? int.tryParse(value.toString()) : null;
+
+  static bool _isIterableOfStrings(Object? object) =>
+      object is Iterable<Object> && object.every((node) => node is String);
+}

lib/src/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/validator.dart

@@ -0,0 +1,19 @@
+part of 'prefer_correct_identifier_length.dart';
+
+class _Validator {
+  final int maxLength;
+  final int minLength;
+  final Iterable<String> exceptions;
+
+  _Validator(this.maxLength, this.minLength, this.exceptions);
+
+  bool isValid(SimpleIdentifier identifier) =>
+      _validate(_getNameWithoutUnderscore(identifier.name));
+
+  bool _validate(String name) =>
+      exceptions.contains(name) ||
+      (name.length >= minLength && name.length <= maxLength);
+
+  String _getNameWithoutUnderscore(String name) =>
+      name.startsWith('_') ? name.replaceFirst('_', '') : name;
+}

lib/src/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/visitor.dart

@@ -0,0 +1,37 @@
+part of 'prefer_correct_identifier_length.dart';
+
+class _Visitor extends ScopeVisitor {
+  final _declarationNodes = <SimpleIdentifier>[];
+  final _Validator validator;
+
+  _Visitor(this.validator);
+
+  Iterable<SimpleIdentifier> get nodes => _declarationNodes;
+
+  @override
+  void visitMethodDeclaration(MethodDeclaration node) {
+    super.visitMethodDeclaration(node);
+
+    if (node.isGetter || node.isSetter && !validator.isValid(node.name)) {
+      _declarationNodes.add(node.name);
+    }
+  }
+
+  @override
+  void visitEnumDeclaration(EnumDeclaration node) {
+    super.visitEnumDeclaration(node);
+
+    for (final node in node.constants) {
+      _declarationNodes.add(node.name);
+    }
+  }
+
+  @override
+  void visitVariableDeclaration(VariableDeclaration node) {
+    super.visitVariableDeclaration(node);
+
+    if (!validator.isValid(node.name)) {
+      _declarationNodes.add(node.name);
+    }
+  }
+}

test/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/examples/class_example.dart

@@ -0,0 +1,28 @@
+class Example {
+  final x = 0; // LINT
+  final y = 0; // LINT
+  final z = 0;
+  final zyt = 0;
+  final property = 0;
+  final multiplatformConfig = 0; // LINT
+  final multiplatformConfigurationPoint = 0; // LINT
+
+  Example.todo() {
+    final u = 1; // LINT
+    const i = 1; // LINT
+  }
+
+  Example._() {
+    final u = 1; // LINT
+    const i = 1; // LINT
+  }
+
+  bool get o => false; // LINT
+
+  bool set p() => true; // LINT
+
+  void test() {
+    final u = 1; // LINT
+    const i = 1; // LINT
+  }
+}

test/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/examples/common_example.dart

@@ -0,0 +1,7 @@
+void test() {
+  final zy = 0; // LINT
+  final _ze = 1; // LINT
+}
+
+final u = 1; // LINT
+const i = 1; // LINT

test/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/examples/enum_example.dart

@@ -0,0 +1,4 @@
+enum Enum {
+  u, // LINT
+  i, // LINT
+}

test/analyzers/lint_analyzer/rules/rules_list/prefer_correct_identifier_length/examples/extension_example.dart

@@ -0,0 +1,6 @@
+extension Extension on String {
+  onExtension() {
+    final u = 1; // LINT
+    const i = 1; // LINT
+  }
+}