Improved avoid_late_keyword to support ignoring the subtype of the …

…node type (#157) (#158)

* Improved `avoid_late_keyword` to support ignoring the subtype of the node type (#157)

* Improved `avoid_late_keyword` to support matching the subtype of the node type (support for nested types for dynamic, Object?, Object) #157

* Update lint_test/avoid_late_keyword_test.dart

Co-authored-by: Yurii Prykhodko <[email protected]>

* Update lib/src/utils/types_utils.dart

Co-authored-by: Yurii Prykhodko <[email protected]>

* Refactored code for `ignored_types` type matching using AST analyzer (#157)

* Divided code into logical parts using the NamedType nodes tree to analyze and compare type names

* Refactored code and reorganized files

---------

Co-authored-by: Yarl745 <[email protected]>
Co-authored-by: Yurii Prykhodko <[email protected]>

lib/src/lints/avoid_late_keyword/avoid_late_keyword_rule.dart

@@ -102,10 +102,8 @@ class AvoidLateKeywordRule extends SolidLintRule<AvoidLateKeywordParameters> {
     final variableType = node.declaredElement?.type;
     if (variableType == null) return false;
 
-    final checkedTypes = [variableType, ...variableType.supertypes]
-        .map((t) => t.getDisplayString(withNullability: false))
-        .toSet();
-
-    return checkedTypes.intersection(ignoredTypes).isNotEmpty;
+    return variableType.hasIgnoredType(
+      ignoredTypes: ignoredTypes,
+    );
   }
 }

lib/src/utils/named_type_utils.dart

@@ -0,0 +1,66 @@
+import 'package:analyzer/dart/analysis/utilities.dart';
+import 'package:analyzer/dart/ast/ast.dart';
+import 'package:analyzer/dart/ast/visitor.dart';
+
+/// Parses the provided type string to extract a [NamedType].
+NamedType parseNamedTypeFromString(String typeString) {
+  try {
+    final namedTypeFinder = _NamedTypeFinder();
+
+    final parseResult = parseString(content: "$typeString _;");
+    parseResult.unit.visitChildren(namedTypeFinder);
+
+    return namedTypeFinder.foundNamedType!;
+  } catch (_) {
+    throw Exception("No NamedType could be parsed from the input "
+        "typeString: '$typeString'. Ensure it's a valid Dart "
+        "type declaration.");
+  }
+}
+
+class _NamedTypeFinder extends GeneralizingAstVisitor<void> {
+  NamedType? _foundNamedType;
+
+  NamedType? get foundNamedType => _foundNamedType;
+
+  @override
+  void visitNamedType(NamedType namedType) {
+    _foundNamedType ??= namedType;
+  }
+}
+
+///
+extension ChildNamedTypes on NamedType {
+  /// Retrieves child [NamedType] instances from type arguments.
+  List<NamedType> get childNamedTypes =>
+      typeArguments?.arguments.whereType<NamedType>().toList() ?? [];
+
+  /// Gets the token name of this type instance.
+  String get tokenName => name2.toString();
+
+  /// Checks if the current token name is 'dynamic'.
+  bool get isDynamic => tokenName == "dynamic";
+
+  /// Checks if the current token name is 'Object'.
+  bool get isObject => tokenName == "Object";
+
+  /// Checks if this node is a subtype of the specified node
+  /// based on their structures.
+  bool isSubtypeOf({required NamedType node}) {
+    if (isDynamic || isObject) return true;
+
+    if (tokenName != node.tokenName) return false;
+
+    if (childNamedTypes.isEmpty) return true;
+
+    if (childNamedTypes.length != node.childNamedTypes.length) return false;
+
+    for (int i = 0; i < childNamedTypes.length; i++) {
+      if (!childNamedTypes[i].isSubtypeOf(node: node.childNamedTypes[i])) {
+        return false;
+      }
+    }
+
+    return true;
+  }
+}

lib/src/utils/types_utils.dart

@@ -22,16 +22,65 @@
 // SOFTWARE.
 // ignore_for_file: public_member_api_docs
 
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:collection/collection.dart';
+import 'package:solid_lints/src/utils/named_type_utils.dart';
 
 extension Subtypes on DartType {
   Iterable<DartType> get supertypes {
     final element = this.element;
     return element is InterfaceElement ? element.allSupertypes : [];
   }
+
+  /// Formats the type string based on nullability and presence of generics.
+  String getTypeString({
+    required bool withGenerics,
+    required bool withNullability,
+  }) {
+    final displayString = getDisplayString(withNullability: withNullability);
+
+    return withGenerics ? displayString : displayString.replaceGenericString();
+  }
+
+  /// Parses a [NamedType] instance from current type.
+  NamedType getNamedType() {
+    final typeString = getTypeString(
+      withGenerics: true,
+      withNullability: false,
+    );
+
+    return parseNamedTypeFromString(typeString);
+  }
+
+  /// Checks if a variable type is among the ignored types.
+  bool hasIgnoredType({required Set<String> ignoredTypes}) {
+    if (ignoredTypes.isEmpty) return false;
+
+    final checkedTypeNodes = [this, ...supertypes].map(
+      (type) => type.getNamedType(),
+    );
+
+    final ignoredTypeNodes = ignoredTypes.map(parseNamedTypeFromString);
+
+    for (final ignoredTypeNode in ignoredTypeNodes) {
+      for (final checkedTypeNode in checkedTypeNodes) {
+        if (ignoredTypeNode.isSubtypeOf(node: checkedTypeNode)) {
+          return true;
+        }
+      }
+    }
+
+    return false;
+  }
+}
+
+extension TypeString on String {
+  static final _genericRegex = RegExp('<.*>');
+
+  String replaceGenericString() => replaceFirst(_genericRegex, '');
 }
 
 bool hasWidgetType(DartType type) =>

lint_test/analysis_options.yaml

@@ -13,9 +13,6 @@ custom_lint:
     - avoid_non_null_assertion
     - avoid_late_keyword:
       allow_initialized: true
-      ignored_types:
-        - ColorTween
-        - AnimationController
     - avoid_global_state
     - avoid_returning_widgets
     - avoid_unnecessary_setstate

lint_test/avoid_late_keyword/no_generics/analysis_options.yaml

@@ -0,0 +1,10 @@
+analyzer:
+  plugins:
+    - ../custom_lint
+
+custom_lint:
+  rules:
+    - avoid_late_keyword:
+      allow_initialized: false
+      ignored_types:
+        - Subscription

lint_test/avoid_late_keyword/no_generics/avoid_late_keyword_no_generics_test.dart

@@ -0,0 +1,42 @@
+// ignore_for_file: prefer_const_declarations, unused_local_variable, prefer_match_file_name
+// ignore_for_file: avoid_global_state
+
+class Subscription<T> {}
+
+class ConcreteTypeWithNoGenerics {}
+
+class NotAllowed {}
+
+/// Check "late" keyword fail
+///
+/// `avoid_late_keyword`
+/// allow_initialized option disabled
+class AvoidLateKeyword {
+  /// expect_lint: avoid_late_keyword
+  late final NotAllowed na1;
+
+  late final Subscription subscription1;
+
+  late final Subscription<ConcreteTypeWithNoGenerics> subscription2;
+
+  late final Subscription<List<int>> subscription3;
+
+  late final Subscription<List<List<int>>> subscription4;
+
+  late final Subscription<Map<dynamic, String>> subscription5;
+
+  void test() {
+    /// expect_lint: avoid_late_keyword
+    late final NotAllowed na1;
+
+    late final Subscription subscription1;
+
+    late final Subscription<ConcreteTypeWithNoGenerics> subscription2;
+
+    late final Subscription<List<int>> subscription3;
+
+    late final Subscription<List<List<int>>> subscription4;
+
+    late final Subscription<Map<dynamic, String>> subscription5;
+  }
+}

lint_test/avoid_late_keyword/with_generics/analysis_options.yaml

@@ -0,0 +1,14 @@
+analyzer:
+  plugins:
+    - ../custom_lint
+
+custom_lint:
+  rules:
+    - avoid_late_keyword:
+      allow_initialized: true
+      ignored_types:
+        - ColorTween
+        - AnimationController
+        - Subscription<List<Object?>>
+        - Subscription<Map<dynamic, String>>
+        - Subscription<ConcreteTypeWithNoGenerics>

lint_test/avoid_late_keyword_test.dart → lint_test/avoid_late_keyword/with_generics/avoid_late_keyword_with_generics_test.dart

@@ -9,6 +9,10 @@ class SubAnimationController extends AnimationController {}
 
 class NotAllowed {}
 
+class Subscription<T> {}
+
+class ConcreteTypeWithNoGenerics {}
+
 /// Check "late" keyword fail
 ///
 /// `avoid_late_keyword`
@@ -37,6 +41,22 @@ class AvoidLateKeyword {
 
   late final na2 = NotAllowed();
 
+  /// expect_lint: avoid_late_keyword
+  late final Subscription<String> subscription1;
+
+  late final Subscription<ConcreteTypeWithNoGenerics> subscription2;
+
+  late final Subscription<List<String>> subscription3;
+
+  late final Subscription<List<List<int>>> subscription4;
+
+  late final Subscription<Map<dynamic, String>> subscription5;
+
+  late final Subscription<Map<String, String>> subscription6;
+
+  /// expect_lint: avoid_late_keyword
+  late final Subscription<Map<String, dynamic>> subscription7;
+
   void test() {
     late final ColorTween colorTween;
 
@@ -60,5 +80,12 @@ class AvoidLateKeyword {
     late final NotAllowed na1;
 
     late final na2 = NotAllowed();
+
+    /// expect_lint: avoid_late_keyword
+    late final Subscription<String> subscription1;
+
+    late final Subscription<ConcreteTypeWithNoGenerics> subscription2;
+
+    late final Subscription<List<String>> subscription3;
   }
 }