Update prefer_equatable_mixin for equatable 2.1.0

packages/leancode_lint/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 24.1.0
+
+- Update [`prefer_equatable_mixin`](https://github.com/leancodepl/flutter_corelibrary/tree/master/packages/leancode_lint#prefer_equatable_mixin) to suggest mixing in `Equatable` directly when the linted package depends on `equatable` 2.1.0 or higher, where `EquatableMixin` is deprecated.
+
 # 24.0.0
 
 - Add new custom lints:

packages/leancode_lint/README.md

@@ -826,7 +826,12 @@ None
 
 ### `prefer_equatable_mixin`
 
-**DO** mix in `EquatableMixin` instead of extending `Equatable`.
+**DO** mix in `Equatable` instead of extending it.
+
+Since `equatable` 2.1.0, `Equatable` can be used as a mixin and `EquatableMixin`
+is deprecated. This lint suggests mixing in `Equatable` directly when the package
+depends on `equatable` 2.1.0 or higher, and falls back to suggesting `EquatableMixin`
+for older versions.
 
 **BAD:**
 
@@ -848,6 +853,17 @@ class Foobar extends Equatable {
 ```dart
 import 'package:equatable/equatable.dart';
 
+// `equatable` >= 2.1.0
+class Foobar with Equatable {
+  const Foobar(this.value);
+
+  final int value;
+
+  @override
+  List<Object?> get props => [value];
+}
+
+// `equatable` < 2.1.0
 class Foobar with EquatableMixin {
   const Foobar(this.value);
 

packages/leancode_lint/lib/src/lints/missing_equatable_props.dart

@@ -242,7 +242,7 @@ List<String> _findMissingFieldNames(
 ///
 /// Returns `false` when:
 /// - the superclass has no Equatable-shaped ancestor (e.g. a plain class that
-///   only mixes in `EquatableMixin` — its supertype is [Object]);
+///   only mixes in `Equatable`/`EquatableMixin` — its supertype is [Object]);
 /// - the superclass is `Equatable` or `EquatableMixin` itself (both declare
 ///   `props` as abstract, so `super.props` would target the abstract member);
 /// - the superclass is an intermediate Equatable-shaped class that does not

packages/leancode_lint/lib/src/lints/prefer_equatable_mixin.dart

@@ -5,6 +5,7 @@ import 'package:analyzer/analysis_rule/rule_context.dart';
 import 'package:analyzer/analysis_rule/rule_visitor_registry.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/error/error.dart';
 import 'package:analyzer_plugin/utilities/change_builder/change_builder_core.dart';
 import 'package:analyzer_plugin/utilities/fixes/fixes.dart';
@@ -17,7 +18,7 @@ class PreferEquatableMixin extends AnalysisRule {
 
   static const code = LintCode(
     'prefer_equatable_mixin',
-    'The class {0} should mix in EquatableMixin instead of extending Equatable.',
+    'The class {0} should mix in {1} instead of extending Equatable.',
     correctionMessage: 'Replace with a mixin.',
     severity: .WARNING,
   );
@@ -69,20 +70,31 @@ class _Visitor extends SimpleAstVisitor<void> {
     if (isEquatable && !isEquatableMixin) {
       rule.reportAtNode(
         extendsClause.superclass,
-        arguments: [node.namePart.typeName.lexeme],
+        arguments: [
+          node.namePart.typeName.lexeme,
+          _recommendedMixinName(extendsClause.superclass),
+        ],
       );
     }
   }
 }
 
+/// Recommends `Equatable` for `equatable` >= 2.1.0 (where it's a `mixin class`)
+/// and the deprecated `EquatableMixin` for older versions.
+String _recommendedMixinName(NamedType equatableType) =>
+    switch (equatableType.element) {
+      ClassElement(isMixinClass: true) => 'Equatable',
+      _ => 'EquatableMixin',
+    };
+
 class ConvertToEquatableMixin extends ResolvedCorrectionProducer {
   ConvertToEquatableMixin({required super.context});
 
   @override
   FixKind get fixKind => const .new(
     'leancode_lint.fix.convertToEquatableMixin',
     DartFixKindPriority.standard,
-    'Convert to EquatableMixin',
+    'Convert to a mixin',
   );
 
   @override
@@ -93,6 +105,7 @@ class ConvertToEquatableMixin extends ResolvedCorrectionProducer {
     final classDeclaration = node.thisOrAncestorOfType<ClassDeclaration>()!;
     final extendsClause = classDeclaration.extendsClause!;
     final withClause = classDeclaration.withClause;
+    final mixinName = _recommendedMixinName(extendsClause.superclass);
 
     await builder.addDartFileEdit(file, (builder) {
       if (withClause != null) {
@@ -103,12 +116,12 @@ class ConvertToEquatableMixin extends ResolvedCorrectionProducer {
           )
           ..addSimpleInsertion(
             withClause.mixinTypes.first.offset,
-            'EquatableMixin, ',
+            '$mixinName, ',
           );
       } else {
         builder.addSimpleReplacement(
           extendsClause.sourceRange,
-          'with EquatableMixin',
+          'with $mixinName',
         );
       }
     });

packages/leancode_lint/pubspec.yaml

@@ -1,5 +1,5 @@
 name: leancode_lint
-version: 24.0.0
+version: 24.1.0
 homepage: https://github.com/leancodepl/flutter_corelibrary/tree/master/packages/leancode_lint
 repository: https://github.com/leancodepl/flutter_corelibrary
 description: Robust and high-quality lint rules used at LeanCode.

packages/leancode_lint/test/assert_ranges.dart

@@ -9,6 +9,7 @@ extension AssertDiagnosticsInRangesX on AnalysisRuleTest {
     bool positionShorthand = true,
     bool rangeShorthand = true,
     bool zeroWidthMarker = true,
+    List<List<Pattern>> messageContainsAll = const [],
   }) {
     final code = TestCode.parse(
       content,
@@ -17,8 +18,12 @@ extension AssertDiagnosticsInRangesX on AnalysisRuleTest {
       zeroWidthMarker: zeroWidthMarker,
     );
     return assertDiagnostics(code.code, [
-      for (final range in code.ranges)
-        lint(range.sourceRange.offset, range.sourceRange.length),
+      for (final (index, range) in code.ranges.indexed)
+        lint(
+          range.sourceRange.offset,
+          range.sourceRange.length,
+          messageContainsAll: messageContainsAll.elementAtOrNull(index) ?? [],
+        ),
       for (final position in code.positions) lint(position.offset, 0),
     ]);
   }

packages/leancode_lint/test/mock_libraries/equatable.dart

@@ -1,9 +1,31 @@
 part of '../mock_libraries.dart';
 
+/// Mocks `equatable` 2.1.0 or higher, where `Equatable` can be used as a mixin
+/// and `EquatableMixin` is deprecated.
 mixin MockEquatable on AnalysisRuleTest {
   @override
   void setUp() {
     newPackage('equatable').addFile('lib/equatable.dart', '''
+abstract mixin class Equatable {
+  const Equatable();
+  List<Object?> get props;
+}
+
+@Deprecated('use Equatable as a mixin instead')
+mixin EquatableMixin {
+  List<Object?> get props;
+}
+''');
+    super.setUp();
+  }
+}
+
+/// Mocks `equatable` older than 2.1.0, where `Equatable` cannot be used as a
+/// mixin and `EquatableMixin` should be used instead.
+mixin MockOldEquatable on AnalysisRuleTest {
+  @override
+  void setUp() {
+    newPackage('equatable').addFile('lib/equatable.dart', '''
 class Equatable {
   const Equatable();
   List<Object?> get props;

packages/leancode_lint/test/test_cases/missing_equatable_props_test.dart

@@ -24,7 +24,7 @@ class MissingEquatablePropsTest extends AnalysisRuleTest with MockEquatable {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.b);
 
   final int a;
@@ -40,6 +40,24 @@ class MyState with EquatableMixin {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
+class MyState with Equatable {
+  MyState(this.a, this.b, this.c);
+
+  final int a;
+  final String b;
+  final double c;
+
+  @override
+  List<Object?> get props => /*[0*/[a]/*0]*/;
+}
+''');
+  }
+
+  Future<void> test_missing_fields_in_deprecated_mixin_class() async {
+    await assertDiagnosticsInRanges('''
+import 'package:equatable/equatable.dart';
+
+// ignore: deprecated_member_use
 class MyState with EquatableMixin {
   MyState(this.a, this.b, this.c);
 
@@ -73,7 +91,7 @@ class MyState extends Equatable {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a);
 
   static const int unused = 0;
@@ -89,7 +107,7 @@ class MyState with EquatableMixin {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a);
 
   final int a;
@@ -105,7 +123,7 @@ class MyState with EquatableMixin {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.b);
 
   final int a;
@@ -135,7 +153,7 @@ class Plain {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.b);
 
   final int a, b;
@@ -150,7 +168,7 @@ class MyState with EquatableMixin {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.onTap);
 
   final int a;
@@ -166,7 +184,7 @@ class MyState with EquatableMixin {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.b);
 
   final int a;
@@ -182,7 +200,7 @@ class MyState with EquatableMixin {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
-class Parent with EquatableMixin {
+class Parent with Equatable {
   Parent(this.a);
 
   final int a;
@@ -206,7 +224,7 @@ class Sub extends Parent {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class Parent with EquatableMixin {
+class Parent with Equatable {
   Parent(this.a);
 
   final int a;
@@ -230,7 +248,7 @@ class Sub extends Parent {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class Parent with EquatableMixin {
+class Parent with Equatable {
   Parent(this.a);
 
   final int a;
@@ -250,7 +268,8 @@ class Sub extends Parent {
 ''');
   }
 
-  Future<void> test_super_props_not_suggested_for_direct_equatable_subclass() async {
+  Future<void>
+  test_super_props_not_suggested_for_direct_equatable_subclass() async {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
@@ -266,7 +285,8 @@ class MyState extends Equatable {
 ''');
   }
 
-  Future<void> test_super_props_not_suggested_when_parent_has_no_concrete_props() async {
+  Future<void>
+  test_super_props_not_suggested_when_parent_has_no_concrete_props() async {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
@@ -286,7 +306,8 @@ class Sub extends AbstractBase {
 ''');
   }
 
-  Future<void> test_no_diagnostic_when_parent_has_no_concrete_props_and_all_fields_listed() async {
+  Future<void>
+  test_no_diagnostic_when_parent_has_no_concrete_props_and_all_fields_listed() async {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
@@ -306,7 +327,8 @@ class Sub extends AbstractBase {
 ''');
   }
 
-  Future<void> test_super_props_suggested_when_abstract_parent_has_concrete_props() async {
+  Future<void>
+  test_super_props_suggested_when_abstract_parent_has_concrete_props() async {
     await assertDiagnosticsInRanges('''
 import 'package:equatable/equatable.dart';
 
@@ -334,7 +356,7 @@ class Sub extends AbstractBase {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.b);
 
   final int a;
@@ -352,7 +374,7 @@ class MyState with EquatableMixin {
     await assertNoDiagnostics('''
 import 'package:equatable/equatable.dart';
 
-class MyState with EquatableMixin {
+class MyState with Equatable {
   MyState(this.a, this.b);
 
   final int a;