analyzer: Simplify FormatterOptions impl

Change-Id: If68c615efcbec4ad07be3a51fc267a53829924c3
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/389020
Reviewed-by: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Samuel Rawlins <[email protected]>

Author: srawlins

pkg/analyzer/lib/dart/analysis/formatter_options.dart

@@ -4,9 +4,9 @@
 
 /// A set of options related to the formatter that apply to the code within a
 /// single analysis context.
-///
-/// Clients may not extend, implement or mix-in this class.
-abstract class FormatterOptions {
+final class FormatterOptions {
   /// The width configured for where the formatter should wrap code.
-  int? get pageWidth;
+  final int? pageWidth;
+
+  FormatterOptions({this.pageWidth});
 }

pkg/analyzer/lib/src/analysis_options/apply_options.dart

@@ -8,7 +8,6 @@ import 'package:analyzer/dart/analysis/formatter_options.dart';
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/source/error_processor.dart';
 import 'package:analyzer/src/analysis_options/code_style_options.dart';
-import 'package:analyzer/src/analysis_options/formatter_options.dart';
 import 'package:analyzer/src/dart/analysis/experiments.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
@@ -159,7 +158,7 @@ extension on AnalysisOptionsImpl {
         pageWidth = formatValue;
       }
     }
-    return FormatterOptionsImpl(this, pageWidth: pageWidth);
+    return FormatterOptions(pageWidth: pageWidth);
   }
 
   void _applyLegacyPlugins(YamlNode? plugins) {

pkg/analyzer/lib/src/analysis_options/formatter_options.dart

@@ -17,7 +17,6 @@ import 'package:analyzer/source/error_processor.dart';
 import 'package:analyzer/source/line_info.dart';
 import 'package:analyzer/source/source.dart';
 import 'package:analyzer/src/analysis_options/code_style_options.dart';
-import 'package:analyzer/src/analysis_options/formatter_options.dart';
 import 'package:analyzer/src/dart/analysis/experiments.dart';
 import 'package:analyzer/src/generated/source.dart' show SourceFactory;
 import 'package:analyzer/src/lint/linter.dart';
@@ -239,17 +238,16 @@ class AnalysisOptionsImpl implements AnalysisOptions {
   late CodeStyleOptions codeStyleOptions;
 
   @override
-  late FormatterOptions formatterOptions;
+  FormatterOptions formatterOptions = FormatterOptions();
 
-  /// The set of "un-ignorable" error names, as parsed in [AnalyzerOptions] from
-  /// an analysis options file.
+  /// The set of "un-ignorable" error names, as parsed from an analysis options
+  /// file.
   Set<String> unignorableNames = {};
 
   /// Initialize a newly created set of analysis options to have their default
   /// values.
   AnalysisOptionsImpl({this.file}) {
     codeStyleOptions = CodeStyleOptionsImpl(this, useFormatter: false);
-    formatterOptions = FormatterOptionsImpl(this);
   }
 
   /// Initialize a newly created set of analysis options to have the same values