Fix avoid-late if initialized (#71)

lib/lints/avoid_late_keyword/avoid_late_keyword_rule.dart

@@ -1,10 +1,13 @@
+import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/error/listener.dart';
 import 'package:custom_lint_builder/custom_lint_builder.dart';
+import 'package:solid_lints/lints/avoid_late_keyword/models/avoid_late_keyword_parameters.dart';
 import 'package:solid_lints/models/rule_config.dart';
 import 'package:solid_lints/models/solid_lint_rule.dart';
+import 'package:solid_lints/utils/types_utils.dart';
 
 /// A `late` keyword rule which forbids using it to avoid runtime exceptions.
-class AvoidLateKeywordRule extends SolidLintRule {
+class AvoidLateKeywordRule extends SolidLintRule<AvoidLateKeywordParameters> {
   /// The [LintCode] of this lint rule that represents
   /// the error whether we use `late` keyword.
   static const lintName = 'avoid_late_keyword';
@@ -17,6 +20,7 @@ class AvoidLateKeywordRule extends SolidLintRule {
     final rule = RuleConfig(
       configs: configs,
       name: lintName,
+      paramsParser: AvoidLateKeywordParameters.fromJson,
       problemMessage: (_) => 'Avoid using the "late" keyword. '
           'It may result in runtime exceptions.',
     );
@@ -31,9 +35,37 @@ class AvoidLateKeywordRule extends SolidLintRule {
     CustomLintContext context,
   ) {
     context.registry.addVariableDeclaration((node) {
-      if (node.declaredElement?.isLate ?? false) {
+      if (_shouldLint(node)) {
         reporter.reportErrorForNode(code, node);
       }
     });
   }
+
+  bool _shouldLint(VariableDeclaration node) {
+    final isLateDeclaration = node.declaredElement?.isLate ?? false;
+    if (!isLateDeclaration) return false;
+
+    final hasIgnoredType = _hasIgnoredType(node);
+    if (hasIgnoredType) return false;
+
+    final allowInitialized = config.parameters.allowInitialized;
+    if (!allowInitialized) return true;
+
+    final hasInitializer = node.initializer != null;
+    return !hasInitializer;
+  }
+
+  bool _hasIgnoredType(VariableDeclaration node) {
+    final ignoredTypes = config.parameters.ignoredTypes.toSet();
+    if (ignoredTypes.isEmpty) return false;
+
+    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;
+  }
 }

lib/lints/avoid_late_keyword/models/avoid_late_keyword_parameters.dart

@@ -0,0 +1,28 @@
+/// A data model class that represents the "avoid late keyword" input
+/// parameters.
+class AvoidLateKeywordParameters {
+  /// Allow immediately initialised late variables.
+  ///
+  /// ```dart
+  /// late var ok = 0; // ok when allowInitialized == true
+  /// late var notOk; // initialized elsewhere, not allowed
+  /// ```
+  final bool allowInitialized;
+
+  /// Types that would be ignored by avoid-late rule
+  final Iterable<String> ignoredTypes;
+
+  /// Constructor for [AvoidLateKeywordParameters] model
+  const AvoidLateKeywordParameters({
+    this.allowInitialized = false,
+    this.ignoredTypes = const [],
+  });
+
+  /// Method for creating from json data
+  factory AvoidLateKeywordParameters.fromJson(Map<String, Object?> json) =>
+      AvoidLateKeywordParameters(
+        allowInitialized: json['allow_initialized'] as bool? ?? false,
+        ignoredTypes:
+            List<String>.from(json['ignored_types'] as Iterable? ?? []),
+      );
+}

lib/utils/types_utils.dart

@@ -22,10 +22,18 @@
 // SOFTWARE.
 // ignore_for_file: public_member_api_docs
 
+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';
 
+extension Subtypes on DartType {
+  Iterable<DartType> get supertypes {
+    final element = this.element;
+    return element is InterfaceElement ? element.allSupertypes : [];
+  }
+}
+
 bool hasWidgetType(DartType type) =>
     (isWidgetOrSubclass(type) ||
         _isIterable(type) ||

lint_test/analysis_options.yaml

@@ -11,7 +11,11 @@ custom_lint:
     - function_lines_of_code:
       max_lines: 50
     - avoid_non_null_assertion
-    - avoid_late_keyword
+    - avoid_late_keyword:
+      allow_initialized: true
+      ignored_types:
+        - ColorTween
+        - AnimationController
     - avoid_global_state
     - avoid_returning_widgets
     - avoid_unnecessary_setstate

lint_test/avoid_late_keyword_allow_initialized_test/analysis_options.yaml

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

lint_test/avoid_late_keyword_allow_initialized_test/avoid_late_keyword_allow_initialized_test.dart

@@ -0,0 +1,76 @@
+// ignore_for_file: prefer_const_declarations, unused_local_variable, prefer_match_file_name
+// ignore_for_file: avoid_global_state
+
+abstract class Animation {}
+
+class AnimationController implements Animation {}
+
+class SubAnimationController extends AnimationController {}
+
+class ColorTween {}
+
+/// Check "late" keyword fail
+///
+/// `avoid_late_keyword`
+/// allow_initialized option disabled
+class AvoidLateKeyword {
+  late final Animation animation1;
+
+  late final animation2 = AnimationController();
+
+  late final animation3 = SubAnimationController();
+
+  /// expect_lint: avoid_late_keyword
+  late final ColorTween colorTween1;
+
+  /// expect_lint: avoid_late_keyword
+  late final colorTween2 = ColorTween();
+
+  /// expect_lint: avoid_late_keyword
+  late final colorTween3 = colorTween2;
+
+  late final AnimationController controller1;
+
+  /// expect_lint: avoid_late_keyword
+  late final field1 = 'string';
+
+  /// expect_lint: avoid_late_keyword
+  late final String field2;
+
+  /// expect_lint: avoid_late_keyword
+  late final String field3 = 'string';
+
+  /// expect_lint: avoid_late_keyword
+  late final field4;
+
+  void test() {
+    late final Animation animation1;
+
+    late final animation2 = AnimationController();
+
+    late final animation3 = SubAnimationController();
+
+    /// expect_lint: avoid_late_keyword
+    late final ColorTween colorTween1;
+
+    /// expect_lint: avoid_late_keyword
+    late final colorTween2 = ColorTween();
+
+    /// expect_lint: avoid_late_keyword
+    late final colorTween3 = colorTween2;
+
+    late final AnimationController controller1;
+
+    /// expect_lint: avoid_late_keyword
+    late final local1 = 'string';
+
+    /// expect_lint: avoid_late_keyword
+    late final String local2;
+
+    /// expect_lint: avoid_late_keyword
+    late final String local4 = 'string';
+
+    /// expect_lint: avoid_late_keyword
+    late final local3;
+  }
+}

lint_test/avoid_late_keyword_allow_initialized_test/pubspec.yaml

@@ -0,0 +1,11 @@
+name: avoid_late_keyword_allow_initialized_test
+publish_to: none
+
+environment:
+  sdk: '>=3.0.0 <4.0.0'
+
+dependencies:
+
+dev_dependencies:
+  solid_lints:
+    path: ../../

lint_test/avoid_late_keyword_test.dart

@@ -1,21 +1,64 @@
 // ignore_for_file: prefer_const_declarations, unused_local_variable, prefer_match_file_name
 // ignore_for_file: avoid_global_state
 
+class ColorTween {}
+
+class AnimationController {}
+
+class SubAnimationController extends AnimationController {}
+
+class NotAllowed {}
+
 /// Check "late" keyword fail
 ///
 /// `avoid_late_keyword`
+/// allow_initialized option enabled
 class AvoidLateKeyword {
-  /// expect_lint: avoid_late_keyword
+  late final ColorTween colorTween;
+
+  late final AnimationController controller1;
+
+  late final SubAnimationController controller2;
+
+  late final controller3 = AnimationController();
+
+  late final controller4 = SubAnimationController();
+
   late final field1 = 'string';
 
   /// expect_lint: avoid_late_keyword
-  late String field2;
+  late final String field2;
+
+  /// expect_lint: avoid_late_keyword
+  late final field3;
+
+  /// expect_lint: avoid_late_keyword
+  late final NotAllowed na1;
+
+  late final na2 = NotAllowed();
 
   void test() {
+    late final ColorTween colorTween;
+
+    late final AnimationController controller1;
+
+    late final SubAnimationController controller2;
+
+    late final controller3 = AnimationController();
+
+    late final controller4 = SubAnimationController();
+
+    late final local1 = 'string';
+
     /// expect_lint: avoid_late_keyword
-    late final field3 = 'string';
+    late final String local2;
 
     /// expect_lint: avoid_late_keyword
-    late String field4;
+    late final local3;
+
+    /// expect_lint: avoid_late_keyword
+    late final NotAllowed na1;
+
+    late final na2 = NotAllowed();
   }
 }