Remove RuleState type hierarchy with an enum and condensed constructors

Change-Id: I07ee606b00467b8113f1722dba21b8c16cfe85b3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/429900
Commit-Queue: Samuel Rawlins <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: srawlins

pkg/analysis_server/lib/src/services/completion/yaml/analysis_options_generator.dart

@@ -10,7 +10,6 @@ import 'package:analyzer/error/error.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/dart/analysis/experiments.dart';
 import 'package:analyzer/src/lint/registry.dart';
-import 'package:analyzer/src/lint/state.dart';
 import 'package:analyzer/src/task/options.dart';
 
 /// A completion generator that can produce completion suggestions for analysis

pkg/analyzer/lib/src/error/ignore_validator.dart

@@ -9,7 +9,6 @@ import 'package:analyzer/source/line_info.dart';
 import 'package:analyzer/src/error/codes.dart';
 import 'package:analyzer/src/ignore_comments/ignore_info.dart';
 import 'package:analyzer/src/lint/registry.dart';
-import 'package:analyzer/src/lint/state.dart';
 
 /// Used to validate the ignore comments in a single file.
 class IgnoreValidator {
@@ -207,9 +206,9 @@ class IgnoreValidator {
         } else {
           var state = rule.state;
           var since = state.since.toString();
-          if (state is DeprecatedRuleState) {
-            // `todo`(pq): implement
-          } else if (state is RemovedRuleState) {
+          if (state.isDeprecated) {
+            // TODO(pq): implement.
+          } else if (state.isRemoved) {
             var replacedBy = state.replacedBy;
             if (replacedBy != null) {
               _errorReporter.atOffset(

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

@@ -7,7 +7,6 @@ import 'package:analyzer/error/listener.dart';
 import 'package:analyzer/src/analysis_options/error/option_codes.dart';
 import 'package:analyzer/src/lint/linter.dart';
 import 'package:analyzer/src/lint/registry.dart';
-import 'package:analyzer/src/lint/state.dart';
 import 'package:analyzer/src/plugin/options.dart';
 import 'package:analyzer/src/util/yaml.dart';
 import 'package:collection/collection.dart';
@@ -39,12 +38,11 @@ class LinterRuleOptionsValidator extends OptionsValidator {
       .rules
       .firstWhereOrNull((rule) => rule.name == value);
 
-  bool isDeprecatedInCurrentSdk(DeprecatedRuleState state) =>
-      currentSdkAllows(state.since);
+  bool isDeprecatedInCurrentSdk(RuleState state) =>
+      state.isDeprecated && currentSdkAllows(state.since);
 
   bool isRemovedInCurrentSdk(RuleState state) {
-    if (state is! RemovedRuleState) return false;
-    return currentSdkAllows(state.since);
+    return state.isRemoved && currentSdkAllows(state.since);
   }
 
   @override
@@ -103,7 +101,7 @@ class LinterRuleOptionsValidator extends OptionsValidator {
       // includes).
       if (sourceIsOptionsForContextRoot) {
         var state = rule.state;
-        if (state is DeprecatedRuleState && isDeprecatedInCurrentSdk(state)) {
+        if (state.isDeprecated && isDeprecatedInCurrentSdk(state)) {
           var replacedBy = state.replacedBy;
           if (replacedBy != null) {
             reporter.atSourceSpan(
@@ -120,7 +118,7 @@ class LinterRuleOptionsValidator extends OptionsValidator {
           }
         } else if (isRemovedInCurrentSdk(state)) {
           var since = state.since.toString();
-          var replacedBy = (state as RemovedRuleState).replacedBy;
+          var replacedBy = state.replacedBy;
           if (replacedBy != null) {
             reporter.atSourceSpan(
               node.span,

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

@@ -16,88 +16,57 @@ final Version dart3_3 = Version(3, 3, 0);
 @Deprecated("Prefer to use 'RuleState'")
 typedef State = RuleState;
 
-/// A state that marks an analysis rule as deprecated.
-final class DeprecatedRuleState extends RuleState {
-  /// The optional name of an analysis rule which replaces the rule with this
-  /// state.
-  final String? replacedBy;
-
-  const DeprecatedRuleState._({super.since, this.replacedBy});
-
-  @override
-  String get label => 'deprecated';
-}
-
-/// A state that marks an analysis rule as experimental.
-final class ExperimentalRuleState extends RuleState {
-  const ExperimentalRuleState._({super.since});
-
-  @override
-  String get label => 'experimental';
-}
-
-/// A state that marks an analysis rule as for internal (Dart SDK) use only.
-final class InternalRuleState extends RuleState {
-  const InternalRuleState._({super.since});
+/// Describes the state of an analysis rule.
+final class RuleState {
+  /// An Optional Dart language version that identifies the start of this state.
+  final Version? since;
 
-  @override
-  String get label => 'internal';
-}
+  final _RuleStateType _type;
 
-/// A state that identifies an analysis rule as having been removed.
-final class RemovedRuleState extends RuleState {
-  /// An optional lint name that replaces the rule with this state.
+  /// The optional name of an analysis rule which replaces the rule with this
+  /// state.
   final String? replacedBy;
 
-  const RemovedRuleState._({super.since, this.replacedBy});
+  /// Initializes a state that marks an analysis rule as deprecated.
+  const RuleState.deprecated({this.since, this.replacedBy})
+    : _type = _RuleStateType.deprecated;
 
-  @override
-  String get label => 'removed';
-}
+  /// Initializes a state that marks an analysis rule as experimental.
+  const RuleState.experimental({this.since})
+    : _type = _RuleStateType.experimental,
+      replacedBy = null;
 
-/// Describes the state of a lint.
-sealed class RuleState {
-  /// An Optional Dart language version that identifies the start of this state.
-  final Version? since;
+  /// Initializes a state that marks an analysis rule as for internal (Dart SDK)
+  /// use only.
+  const RuleState.internal({this.since})
+    : _type = _RuleStateType.internal,
+      replacedBy = null;
 
-  /// Initialize a newly created State object.
-  const RuleState({this.since});
+  /// Initializes a state that identifies an analysis rule as having been removed.
+  const RuleState.removed({this.since, this.replacedBy})
+    : _type = _RuleStateType.removed;
 
-  /// Initialize a newly created deprecated state with given values.
-  const factory RuleState.deprecated({Version? since, String? replacedBy}) =
-      DeprecatedRuleState._;
+  /// Initializes a state that marks an analysis rule as stable.
+  const RuleState.stable({this.since})
+    : _type = _RuleStateType.stable,
+      replacedBy = null;
 
-  /// Initialize a newly created experimental state with given values.
-  const factory RuleState.experimental({Version? since}) =
-      ExperimentalRuleState._;
+  /// Whether this state marks an analysis rule as deprecated.
+  bool get isDeprecated => _type == _RuleStateType.deprecated;
 
-  /// Initialize a newly created internal state with given values.
-  const factory RuleState.internal({Version? since}) = InternalRuleState._;
+  /// Whether this state marks an analysis rule as experimental.
+  bool get isExperimental => _type == _RuleStateType.experimental;
 
-  /// Initialize a newly created removed state with given values.
-  const factory RuleState.removed({Version? since, String? replacedBy}) =
-      RemovedRuleState._;
+  /// Whether this state marks an analysis rule as internal.
+  bool get isInternal => _type == _RuleStateType.internal;
 
-  /// Initialize a newly created stable state with given values.
-  const factory RuleState.stable({Version? since}) = StableRuleState._;
+  /// Whether this state marks an analysis rule as removed.
+  bool get isRemoved => _type == _RuleStateType.removed;
 
   /// A short description, suitable for displaying in documentation or a
   /// diagnostic message.
-  String get label;
+  String get label => _type.name;
 }
 
-/// A state that marks an analysis rule as stable.
-final class StableRuleState extends RuleState {
-  const StableRuleState._({super.since});
-
-  @override
-  String get label => 'stable';
-}
-
-extension StateExtension on RuleState {
-  bool get isDeprecated => this is DeprecatedRuleState;
-  bool get isExperimental => this is ExperimentalRuleState;
-  bool get isInternal => this is InternalRuleState;
-  bool get isRemoved => this is RemovedRuleState;
-  bool get isStable => this is StableRuleState;
-}
+/// The type of a rule state.
+enum _RuleStateType { deprecated, experimental, internal, removed, stable }

pkg/linter/tool/checks/check_all_yaml.dart

@@ -6,7 +6,6 @@ import 'dart:io';
 
 import 'package:analyzer/src/lint/io.dart';
 import 'package:analyzer/src/lint/registry.dart';
-import 'package:analyzer/src/lint/state.dart';
 import 'package:linter/src/rules.dart';
 import 'package:yaml/yaml.dart';
 

pkg/linter/tool/machine.dart

@@ -6,7 +6,6 @@ import 'dart:convert';
 import 'dart:io';
 
 import 'package:analyzer/src/lint/registry.dart';
-import 'package:analyzer/src/lint/state.dart';
 import 'package:args/args.dart';
 import 'package:collection/collection.dart';
 import 'package:linter/src/analyzer.dart';