linter: add isEnabled to LinterContext directly

This was previously available as an extension on this class, but we
control the class quite directly. Seems like it should just be an API
of LinterContext.

Change-Id: I9fb61ab4471e859c39d9fa963eed2a3839fca617
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/428925
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: srawlins

pkg/analyzer/lib/src/lint/linter.dart

@@ -2,6 +2,7 @@
 // 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/analysis/features.dart';
 import 'package:analyzer/dart/analysis/results.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ -247,6 +248,9 @@ abstract class LinterContext {
 
   TypeSystem get typeSystem;
 
+  /// Whether the given [feature] is enabled in this linter context.
+  bool isFeatureEnabled(Feature feature);
+
   static bool _isInLibDir(String? filePath, WorkspacePackage? package) {
     if (package == null) return false;
     if (filePath == null) return false;
@@ -298,6 +302,12 @@ final class LinterContextWithParsedResults implements LinterContext {
       throw UnsupportedError(
         'LinterContext with parsed results does not include a TypeSystem',
       );
+
+  @override
+  bool isFeatureEnabled(Feature feature) =>
+      throw UnsupportedError(
+        'LinterContext with parsed results does not include a LibraryElement',
+      );
 }
 
 /// A [LinterContext] for a library, resolved into [ResolvedUnitResult]s.
@@ -347,6 +357,10 @@ final class LinterContextWithResolvedResults implements LinterContext {
   @override
   LibraryElement get libraryElement2 =>
       definingUnit.unit.declaredFragment!.element;
+
+  @override
+  bool isFeatureEnabled(Feature feature) =>
+      libraryElement2.featureSet.isEnabled(feature);
 }
 
 /// Provides access to information needed by lint rules that is not available

pkg/linter/lib/src/extensions.dart

@@ -2,7 +2,6 @@
 // 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/analysis/features.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/constant/value.dart';
@@ -16,7 +15,6 @@ import 'package:analyzer/src/dart/element/type.dart' // ignore: implementation_i
     show InvalidTypeImpl;
 import 'package:collection/collection.dart';
 
-import 'analyzer.dart';
 import 'util/dart_type_utilities.dart';
 
 class EnumLikeClassDescription {
@@ -584,12 +582,6 @@ extension InterfaceTypeExtension on InterfaceType {
       setters.firstWhereOrNull((s) => s.canonicalName == name);
 }
 
-extension LinterContextExtension on LinterContext {
-  /// Whether the given [feature] is enabled in this linter context.
-  bool isEnabled(Feature feature) =>
-      libraryElement2!.featureSet.isEnabled(feature);
-}
-
 extension MethodDeclarationExtension on MethodDeclaration {
   bool get hasInheritedMethod => lookUpInheritedMethod() != null;
 

pkg/linter/lib/src/rules/avoid_renaming_method_parameters.dart

@@ -45,7 +45,9 @@ class _Visitor extends SimpleAstVisitor<void> {
   final LintRule rule;
 
   _Visitor(this.rule, LinterContext context)
-    : _wildCardVariablesEnabled = context.isEnabled(Feature.wildcard_variables);
+    : _wildCardVariablesEnabled = context.isFeatureEnabled(
+        Feature.wildcard_variables,
+      );
 
   bool isWildcardIdentifier(String lexeme) =>
       _wildCardVariablesEnabled && lexeme == '_';

pkg/linter/lib/src/rules/avoid_shadowing_type_parameters.dart

@@ -8,7 +8,6 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/error/error.dart';
 
 import '../analyzer.dart';
-import '../extensions.dart';
 
 const _desc = r'Avoid shadowing type parameters.';
 
@@ -42,7 +41,9 @@ class _Visitor extends SimpleAstVisitor<void> {
   final LintRule rule;
 
   _Visitor(this.rule, LinterContext context)
-    : _wildCardVariablesEnabled = context.isEnabled(Feature.wildcard_variables);
+    : _wildCardVariablesEnabled = context.isFeatureEnabled(
+        Feature.wildcard_variables,
+      );
 
   @override
   void visitFunctionDeclarationStatement(FunctionDeclarationStatement node) {

pkg/linter/lib/src/rules/invalid_case_patterns.dart

@@ -10,7 +10,6 @@ import 'package:analyzer/error/error.dart';
 import 'package:analyzer/src/dart/ast/token.dart'; // ignore: implementation_imports
 
 import '../analyzer.dart';
-import '../extensions.dart';
 
 const _desc = r'Use case expressions that are valid in Dart 3.0.';
 
@@ -34,7 +33,7 @@ class InvalidCasePatterns extends LintRule {
   ) {
     // This lint rule is only meant for code which does not have 'patterns'
     // enabled.
-    if (context.isEnabled(Feature.patterns)) return;
+    if (context.isFeatureEnabled(Feature.patterns)) return;
 
     var visitor = _Visitor(this);
     registry.addSwitchCase(this, visitor);

pkg/linter/lib/src/rules/library_prefixes.dart

@@ -8,7 +8,6 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/error/error.dart';
 
 import '../analyzer.dart';
-import '../extensions.dart';
 import '../utils.dart';
 
 const _desc =
@@ -38,7 +37,9 @@ class _Visitor extends SimpleAstVisitor<void> {
   final LintRule rule;
 
   _Visitor(this.rule, LinterContext context)
-    : _wildCardVariablesEnabled = context.isEnabled(Feature.wildcard_variables);
+    : _wildCardVariablesEnabled = context.isFeatureEnabled(
+        Feature.wildcard_variables,
+      );
 
   @override
   void visitImportDirective(ImportDirective node) {

pkg/linter/lib/src/rules/no_leading_underscores_for_library_prefixes.dart

@@ -8,7 +8,6 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/error/error.dart';
 
 import '../analyzer.dart';
-import '../extensions.dart';
 import '../util/ascii_utils.dart';
 
 const _desc = r'Avoid leading underscores for library prefixes.';
@@ -41,7 +40,9 @@ class _Visitor extends SimpleAstVisitor<void> {
   final LintRule rule;
 
   _Visitor(this.rule, LinterContext context)
-    : _wildCardVariablesEnabled = context.isEnabled(Feature.wildcard_variables);
+    : _wildCardVariablesEnabled = context.isFeatureEnabled(
+        Feature.wildcard_variables,
+      );
 
   void checkIdentifier(SimpleIdentifier? id) {
     if (id == null) return;

pkg/linter/lib/src/rules/strict_top_level_inference.dart

@@ -49,7 +49,9 @@ class _Visitor extends SimpleAstVisitor<void> {
   final LinterContext context;
 
   _Visitor(this.rule, this.context)
-    : _wildCardVariablesEnabled = context.isEnabled(Feature.wildcard_variables);
+    : _wildCardVariablesEnabled = context.isFeatureEnabled(
+        Feature.wildcard_variables,
+      );
 
   bool isWildcardIdentifier(String lexeme) =>
       _wildCardVariablesEnabled && lexeme == '_';

pkg/linter/lib/src/rules/switch_on_type.dart

@@ -11,7 +11,6 @@ import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/error/error.dart';
 
 import '../analyzer.dart';
-import '../extensions.dart';
 
 const _desc = "Avoid switch statements on a 'Type'.";
 
@@ -31,7 +30,7 @@ class SwitchOnType extends LintRule {
     NodeLintRegistry registry,
     LinterContext context,
   ) {
-    if (!context.isEnabled(Feature.patterns)) return;
+    if (!context.isFeatureEnabled(Feature.patterns)) return;
     var visitor = _Visitor(this, context);
     registry.addSwitchExpression(this, visitor);
     registry.addSwitchStatement(this, visitor);

pkg/linter/lib/src/rules/unnecessary_breaks.dart

@@ -8,7 +8,6 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/error/error.dart';
 
 import '../analyzer.dart';
-import '../extensions.dart';
 
 const _desc = r"Don't use explicit `break`s when a break is implied.";
 
@@ -24,7 +23,7 @@ class UnnecessaryBreaks extends LintRule {
     NodeLintRegistry registry,
     LinterContext context,
   ) {
-    if (!context.isEnabled(Feature.patterns)) return;
+    if (!context.isFeatureEnabled(Feature.patterns)) return;
 
     var visitor = _Visitor(this);
     registry.addBreakStatement(this, visitor);