diff --git a/lib/options.dart b/lib/options.dart
index 85fdfa67e0..195510823e 100644
--- a/lib/options.dart
+++ b/lib/options.dart
@@ -10,8 +10,8 @@ import 'package:dartdoc/src/package_meta.dart';
 
 /// Helper class that consolidates option contexts for instantiating generators.
 class DartdocGeneratorOptionContext extends DartdocOptionContext {
-  DartdocGeneratorOptionContext(DartdocOptionSet optionSet, Folder? dir,
-      ResourceProvider resourceProvider)
+  DartdocGeneratorOptionContext(
+      DartdocOptionSet optionSet, Folder dir, ResourceProvider resourceProvider)
       : super(optionSet, dir, resourceProvider);
   DartdocGeneratorOptionContext.fromDefaultContextLocation(
       DartdocOptionSet optionSet, ResourceProvider resourceProvider)
@@ -51,8 +51,8 @@ class DartdocGeneratorOptionContext extends DartdocOptionContext {
 
 class DartdocProgramOptionContext extends DartdocGeneratorOptionContext
     with LoggingContext {
-  DartdocProgramOptionContext(DartdocOptionSet optionSet, Folder? dir,
-      ResourceProvider resourceProvider)
+  DartdocProgramOptionContext(
+      DartdocOptionSet optionSet, Folder dir, ResourceProvider resourceProvider)
       : super(optionSet, dir, resourceProvider);
   DartdocProgramOptionContext.fromDefaultContextLocation(
       DartdocOptionSet optionSet, ResourceProvider resourceProvider)
@@ -84,7 +84,7 @@ Future<DartdocProgramOptionContext?> parseOptions(
   List<String> arguments, {
   OptionGenerator? additionalOptions,
 }) async {
-  var optionSet = await DartdocOptionSet.fromOptionGenerators(
+  var optionRoot = await DartdocOptionRoot.fromOptionGenerators(
       'dartdoc',
       [
         createDartdocOptions,
@@ -96,22 +96,22 @@ Future<DartdocProgramOptionContext?> parseOptions(
       packageMetaProvider);
 
   try {
-    optionSet.parseArguments(arguments);
+    optionRoot.parseArguments(arguments);
   } on FormatException catch (e) {
     stderr.writeln(' fatal error: ${e.message}');
     stderr.writeln('');
-    _printUsage(optionSet.argParser);
+    _printUsage(optionRoot.argParser);
     // Do not use exit() as this bypasses --pause-isolates-on-exit
     exitCode = 64;
     return null;
   }
-  if (optionSet['help'].valueAtCurrent()) {
-    _printHelp(optionSet.argParser);
+  if (optionRoot['help'].valueAtCurrent()) {
+    _printHelp(optionRoot.argParser);
     exitCode = 0;
     return null;
   }
-  if (optionSet['version'].valueAtCurrent()) {
-    _printVersion(optionSet.argParser);
+  if (optionRoot['version'].valueAtCurrent()) {
+    _printVersion(optionRoot.argParser);
     exitCode = 0;
     return null;
   }
@@ -119,12 +119,12 @@ Future<DartdocProgramOptionContext?> parseOptions(
   DartdocProgramOptionContext config;
   try {
     config = DartdocProgramOptionContext.fromDefaultContextLocation(
-        optionSet, packageMetaProvider.resourceProvider);
+        optionRoot, packageMetaProvider.resourceProvider);
   } on DartdocOptionError catch (e) {
     stderr.writeln(' fatal error: ${e.message}');
     stderr.writeln('');
     await stderr.flush();
-    _printUsage(optionSet.argParser);
+    _printUsage(optionRoot.argParser);
     exitCode = 64;
     return null;
   }
diff --git a/lib/src/dartdoc_options.dart b/lib/src/dartdoc_options.dart
index a5ecfca71c..544e32dcdf 100644
--- a/lib/src/dartdoc_options.dart
+++ b/lib/src/dartdoc_options.dart
@@ -2,8 +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.
 
-// @dart=2.9
-
 ///
 /// dartdoc's dartdoc_options.yaml configuration file follows similar loading
 /// semantics to that of analysis_options.yaml,
@@ -43,7 +41,7 @@ const bool _kBoolVal = true;
 
 const String compileArgsTagName = 'compile_args';
 
-int get _usageLineLength => stdout.hasTerminal ? stdout.terminalColumns : null;
+int get _usageLineLength => stdout.hasTerminal ? stdout.terminalColumns : 80;
 
 typedef ConvertYamlToType<T> = T Function(YamlMap, String, ResourceProvider);
 
@@ -63,11 +61,11 @@ class CategoryDefinition {
   final String name;
 
   /// Displayed name of the category in docs, or null if there is none.
-  final String _displayName;
+  final String? _displayName;
 
   /// Canonical path of the markdown file used to document this category
   /// (or null if undocumented).
-  final String documentationMarkdown;
+  final String? documentationMarkdown;
 
   CategoryDefinition(this.name, this._displayName, this.documentationMarkdown);
 
@@ -92,12 +90,10 @@ class CategoryConfiguration {
     var newCategoryDefinitions = <String, CategoryDefinition>{};
     for (var entry in yamlMap.entries) {
       var name = entry.key.toString();
-      String displayName;
-      String documentationMarkdown;
       var categoryMap = entry.value;
       if (categoryMap is Map) {
-        displayName = categoryMap['displayName']?.toString();
-        documentationMarkdown = categoryMap['markdown']?.toString();
+        var displayName = categoryMap['displayName']?.toString();
+        var documentationMarkdown = categoryMap['markdown']?.toString();
         if (documentationMarkdown != null) {
           documentationMarkdown = resourceProvider.pathContext.canonicalize(
               resourceProvider.pathContext
@@ -122,9 +118,7 @@ class ToolConfiguration {
 
   final ResourceProvider resourceProvider;
 
-  ToolRunner _runner;
-
-  ToolRunner get runner => _runner ??= ToolRunner(this);
+  late ToolRunner runner = ToolRunner(this);
 
   ToolConfiguration._(this.tools, this.resourceProvider);
 
@@ -140,14 +134,14 @@ class ToolConfiguration {
     for (var entry in yamlMap.entries) {
       var name = entry.key.toString();
       var toolMap = entry.value;
-      List<String> compileArgs;
-      String description;
-      List<String> command;
-      List<String> setupCommand;
+      String? description;
+      List<String>? compileArgs;
+      List<String>? command;
+      List<String>? setupCommand;
       if (toolMap is Map) {
-        description = toolMap['description']?.toString();
-        List<String> findCommand([String prefix = '']) {
-          List<String> command;
+        description = toolMap['description'].toString();
+        List<String>? findCommand([String prefix = '']) {
+          List<String>? command;
           // If the command key is given, then it applies to all platforms.
           var commandFromKey = toolMap.containsKey('${prefix}command')
               ? '${prefix}command'
@@ -183,8 +177,8 @@ class ToolConfiguration {
         command = findCommand();
         setupCommand = findCommand('setup_');
 
-        List<String> findArgs() {
-          List<String> args;
+        List<String>? findArgs() {
+          List<String>? args;
           if (toolMap.containsKey(compileArgsTagName)) {
             var compileArgs = toolMap[compileArgsTagName];
             if (compileArgs is String) {
@@ -289,7 +283,7 @@ class _OptionValueWithContext<T> {
   String canonicalDirectoryPath;
 
   /// If non-null, the basename of the configuration file the value came from.
-  String definingFile;
+  String? definingFile;
 
   /// A [pathLib.Context] variable initialized with canonicalDirectoryPath.
   p.Context pathContext;
@@ -298,10 +292,9 @@ class _OptionValueWithContext<T> {
   ///
   /// [path] is the path where this value came from (not required to be
   /// canonical).
-  _OptionValueWithContext(this.value, String path, {this.definingFile}) {
-    canonicalDirectoryPath = p.canonicalize(path);
-    pathContext = p.Context(current: canonicalDirectoryPath);
-  }
+  _OptionValueWithContext(this.value, String path, {this.definingFile})
+      : canonicalDirectoryPath = p.canonicalize(path),
+        pathContext = p.Context(current: p.canonicalize(path));
 
   /// Assume value is a path, and attempt to resolve it.
   ///
@@ -341,7 +334,7 @@ class _OptionValueWithContext<T> {
 /// [DartdocOptionArgOnly], and [DartdocOptionFileOnly].
 abstract class DartdocOption<T> {
   /// This is the value returned if we couldn't find one otherwise.
-  final T defaultsTo;
+  final T? defaultsTo;
 
   /// Text string for help passed on in command line options.
   final String help;
@@ -379,7 +372,7 @@ abstract class DartdocOption<T> {
   }
 
   /// Closure to convert yaml data into some other structure.
-  ConvertYamlToType<T> _convertYamlToType;
+  final ConvertYamlToType<T>? _convertYamlToType;
 
   // The choice not to use reflection means there's some ugly type checking,
   // somewhat more ugly than we'd have to do anyway to automatically convert
@@ -398,11 +391,6 @@ abstract class DartdocOption<T> {
 
   bool get _isDouble => _kDoubleVal is T;
 
-  DartdocOption _parent;
-
-  /// The parent of this DartdocOption, or null if this is the root.
-  DartdocOption get parent => _parent;
-
   final Map<String, _YamlFileData> __yamlAtCanonicalPathCache = {};
 
   /// Implementation detail for [DartdocOptionFileOnly].  Make sure we use
@@ -410,19 +398,6 @@ abstract class DartdocOption<T> {
   Map<String, _YamlFileData> get _yamlAtCanonicalPathCache =>
       root.__yamlAtCanonicalPathCache;
 
-  final ArgParser __argParser = ArgParser(usageLineLength: _usageLineLength);
-
-  ArgParser get argParser => root.__argParser;
-
-  ArgResults __argResults;
-
-  /// Parse these as string arguments (from argv) with the argument parser.
-  /// Call before calling [valueAt] for any [DartdocOptionArgOnly] or
-  /// [DartdocOptionArgFile] in this tree.
-  void _parseArguments(List<String> arguments) {
-    __argResults = argParser.parse(arguments);
-  }
-
   /// Throw [DartdocFileMissing] with a detailed error message indicating where
   /// the error came from when a file or directory option is missing.
   void _onMissing(
@@ -432,14 +407,14 @@ abstract class DartdocOption<T> {
   void _validatePaths(_OptionValueWithContext<T> valueWithContext) {
     if (!mustExist) return;
     assert(isDir || isFile);
-    List<String> resolvedPaths;
+    var resolvedPaths = <String>[];
     var value = valueWithContext.value;
     if (value is String) {
       resolvedPaths = [valueWithContext.resolvedValue as String];
     } else if (value is List<String>) {
       resolvedPaths = valueWithContext.resolvedValue as List<String>;
     } else if (value is Map<String, String>) {
-      resolvedPaths = (valueWithContext.resolvedValue as Map).values.toList();
+      resolvedPaths = [...(valueWithContext.resolvedValue as Map).values];
     } else {
       assert(
           false,
@@ -458,11 +433,11 @@ abstract class DartdocOption<T> {
 
   /// For a [List<String>] or [String] value, if [isDir] or [isFile] is set,
   /// resolve paths in value relative to canonicalPath.
-  T _handlePathsInContext(_OptionValueWithContext<T> valueWithContext) {
+  T? _handlePathsInContext(_OptionValueWithContext<T>? valueWithContext) {
     if (valueWithContext?.value == null || !(isDir || isFile || isGlob)) {
       return valueWithContext?.value;
     }
-    _validatePaths(valueWithContext);
+    _validatePaths(valueWithContext!);
     return valueWithContext.resolvedValue;
   }
 
@@ -473,17 +448,14 @@ abstract class DartdocOption<T> {
 
   ArgResults get _argResults => root.__argResults;
 
-  /// Set the parent of this [DartdocOption].  Do not call more than once.
-  set parent(DartdocOption newParent) {
-    assert(_parent == null);
-    _parent = newParent;
-  }
+  /// To avoid accessing early, call [add] on the option's parent before
+  /// looking up unless this is a [DartdocRootOption].
+  late final DartdocOption parent;
 
-  /// The root [DartdocOption] containing this object, or [this] if the object
-  /// has no parent.
-  DartdocOption get root {
+  /// The [DartdocOptionRoot] containing this object.
+  DartdocOptionRoot get root {
     DartdocOption p = this;
-    while (p.parent != null) {
+    while (p is! DartdocOptionRoot) {
       p = p.parent;
     }
     return p;
@@ -493,10 +465,11 @@ abstract class DartdocOption<T> {
   Iterable<String> get keys {
     var keyList = <String>[];
     DartdocOption option = this;
-    while (option?.name != null) {
+    while (option is! DartdocOptionRoot) {
       keyList.add(option.name);
       option = option.parent;
     }
+    keyList.add(option.name);
     return keyList.reversed;
   }
 
@@ -514,23 +487,15 @@ abstract class DartdocOption<T> {
   /// type.  If [mustExist] is true, will throw [DartdocFileMissing] for command
   /// line parameters and file paths in config files that don't point to
   /// corresponding files or directories.
-  T valueAt(Folder dir);
+  T? valueAt(Folder dir);
 
   /// Calls [valueAt] with the working directory at the start of the program.
-  T valueAtCurrent() => valueAt(_directoryCurrent);
-
-  Folder __directoryCurrent;
-  Folder get _directoryCurrent =>
-      __directoryCurrent ??= resourceProvider.getFolder(_directoryCurrentPath);
-
-  String __directoryCurrentPath;
-  String get _directoryCurrentPath =>
-      __directoryCurrentPath ??= resourceProvider.pathContext.current;
+  T? valueAtCurrent() => valueAt(_directoryCurrent);
 
-  /// Calls [valueAt] on the directory this element is defined in.
-  T valueAtElement(Element element) =>
-      valueAt(resourceProvider.getFolder(resourceProvider.pathContext.normalize(
-          resourceProvider.pathContext.basename(element.source.fullName))));
+  late final Folder _directoryCurrent =
+      resourceProvider.getFolder(_directoryCurrentPath);
+  late final String _directoryCurrentPath =
+      resourceProvider.pathContext.current;
 
   /// Adds a DartdocOption to the children of this DartdocOption.
   void add(DartdocOption option) {
@@ -539,19 +504,20 @@ abstract class DartdocOption<T> {
           'Tried to add two children with the same name: ${option.name}');
     }
     _children[option.name] = option;
+    // TODO(jcollins-g): Consider a stronger refactor that doesn't rely on
+    // post-construction setup for [parent].
     option.parent = this;
-    option.traverse((option) => option._onAdd());
   }
 
-  /// This method is guaranteed to be called when [this] or any parent is added.
-  void _onAdd() {}
+  /// This method is called when parsing options to set up the [ArgParser].
+  void _addToArgParser(ArgParser argParser) {}
 
   /// Adds a list of dartdoc options to the children of this DartdocOption.
   void addAll(Iterable<DartdocOption> options) => options.forEach(add);
 
   /// Get the immediate child of this node named [name].
   DartdocOption<dynamic> operator [](String name) {
-    return _children[name];
+    return _children[name]!;
   }
 
   /// Apply the function [visit] to [this] and all children.
@@ -565,7 +531,8 @@ abstract class DartdocOption<T> {
 /// overridden by a file.
 class DartdocOptionFileSynth<T> extends DartdocOption<T>
     with DartdocSyntheticOption<T>, _DartdocFileOption<T> {
-  bool _parentDirOverridesChild;
+  @override
+  final bool parentDirOverridesChild;
   @override
   final T Function(DartdocSyntheticOption<T>, Folder) _compute;
 
@@ -574,15 +541,13 @@ class DartdocOptionFileSynth<T> extends DartdocOption<T>
       {bool mustExist = false,
       String help = '',
       OptionKind optionIs = OptionKind.other,
-      bool parentDirOverridesChild,
-      ConvertYamlToType<T> convertYamlToType})
+      this.parentDirOverridesChild = false,
+      ConvertYamlToType<T>? convertYamlToType})
       : super(name, null, help, optionIs, mustExist, convertYamlToType,
-            resourceProvider) {
-    _parentDirOverridesChild = parentDirOverridesChild;
-  }
+            resourceProvider);
 
   @override
-  T valueAt(Folder dir) {
+  T? valueAt(Folder dir) {
     var result = _valueAtFromFile(dir);
     if (result?.definingFile != null) {
       return _handlePathsInContext(result);
@@ -599,37 +564,35 @@ class DartdocOptionFileSynth<T> extends DartdocOption<T>
       _onMissingFromSynthetic(valueWithContext, missingPath);
     }
   }
-
-  @override
-  bool get parentDirOverridesChild => _parentDirOverridesChild;
 }
 
 /// A class that defaults to a value computed from a closure, but can
 /// be overridden on the command line.
 class DartdocOptionArgSynth<T> extends DartdocOption<T>
     with DartdocSyntheticOption<T>, _DartdocArgOption<T> {
-  String _abbr;
-  bool _hide;
-  bool _negatable;
-  bool _splitCommas;
+  @override
+  final String? abbr;
+  @override
+  final bool hide;
+  @override
+  final bool negatable;
+  @override
+  final bool splitCommas;
 
   @override
   final T Function(DartdocSyntheticOption<T>, Folder) _compute;
 
   DartdocOptionArgSynth(
       String name, this._compute, ResourceProvider resourceProvider,
-      {String abbr,
+      {this.abbr,
       bool mustExist = false,
       String help = '',
-      bool hide = false,
+      this.hide = false,
       OptionKind optionIs = OptionKind.other,
-      bool negatable = false,
-      bool splitCommas})
+      this.negatable = false,
+      this.splitCommas = false})
       : super(name, null, help, optionIs, mustExist, null, resourceProvider) {
-    _hide = hide;
-    _negatable = negatable;
-    _splitCommas = splitCommas;
-    _abbr = abbr;
+    assert(T is! Iterable || splitCommas == true);
   }
 
   @override
@@ -639,24 +602,12 @@ class DartdocOptionArgSynth<T> extends DartdocOption<T>
   }
 
   @override
-  T valueAt(Folder dir) {
+  T? valueAt(Folder dir) {
     if (_argResults.wasParsed(argName)) {
       return _valueAtFromArgs();
     }
     return _valueAtFromSynthetic(dir);
   }
-
-  @override
-  String get abbr => _abbr;
-
-  @override
-  bool get hide => _hide;
-
-  @override
-  bool get negatable => _negatable;
-
-  @override
-  bool get splitCommas => _splitCommas;
 }
 
 /// A synthetic option takes a closure at construction time that computes
@@ -681,9 +632,9 @@ abstract class DartdocSyntheticOption<T> implements DartdocOption<T> {
   T Function(DartdocSyntheticOption<T>, Folder) get _compute;
 
   @override
-  T valueAt(Folder dir) => _valueAtFromSynthetic(dir);
+  T? valueAt(Folder dir) => _valueAtFromSynthetic(dir);
 
-  T _valueAtFromSynthetic(Folder dir) {
+  T? _valueAtFromSynthetic(Folder dir) {
     var context = _OptionValueWithContext<T>(_compute(this, dir), dir.path);
     return _handlePathsInContext(context);
   }
@@ -705,12 +656,13 @@ abstract class DartdocSyntheticOption<T> implements DartdocOption<T> {
 typedef OptionGenerator = Future<List<DartdocOption>> Function(
     PackageMetaProvider);
 
-/// A [DartdocOption] that only contains other [DartdocOption]s and is not an
-/// option itself.
-class DartdocOptionSet extends DartdocOption<void> {
-  DartdocOptionSet(String name, ResourceProvider resourceProvider)
-      : super(
-            name, null, null, OptionKind.other, false, null, resourceProvider);
+/// This is a [DartdocOptionSet] used as a root node.
+class DartdocOptionRoot extends DartdocOptionSet {
+  DartdocOptionRoot(String name, ResourceProvider resourceProvider)
+      : super(name, resourceProvider);
+
+  late final ArgParser _argParser =
+      ArgParser(usageLineLength: _usageLineLength);
 
   /// Asynchronous factory that is the main entry point to initialize Dartdoc
   /// options for use.
@@ -718,26 +670,37 @@ class DartdocOptionSet extends DartdocOption<void> {
   /// [name] is the top level key for the option set.
   /// [optionGenerators] is a sequence of asynchronous functions that return
   /// [DartdocOption]s that will be added to the new option set.
-  static Future<DartdocOptionSet> fromOptionGenerators(
+  static Future<DartdocOptionRoot> fromOptionGenerators(
       String name,
       Iterable<OptionGenerator> optionGenerators,
       PackageMetaProvider packageMetaProvider) async {
     var optionSet =
-        DartdocOptionSet(name, packageMetaProvider.resourceProvider);
+        DartdocOptionRoot(name, packageMetaProvider.resourceProvider);
     for (var generator in optionGenerators) {
       optionSet.addAll(await generator(packageMetaProvider));
     }
     return optionSet;
   }
 
-  /// [DartdocOptionSet] always has the null value.
-  @override
-  void valueAt(Folder dir) => null;
+  ArgParser get argParser => _argParser;
 
-  /// Since we have no value, [_onMissing] does nothing.
-  @override
-  void _onMissing(
-      _OptionValueWithContext<void> valueWithContext, String missingFilename) {}
+  /// Initialized via [_parseArguments].
+  late ArgResults __argResults;
+
+  bool _argParserInitialized = false;
+
+  /// Parse these as string arguments (from argv) with the argument parser.
+  /// Call before calling [valueAt] for any [DartdocOptionArgOnly] or
+  /// [DartdocOptionArgFile] in this tree.
+  void _parseArguments(List<String> arguments) {
+    if (!_argParserInitialized) {
+      _argParserInitialized = true;
+      traverse((DartdocOption option) {
+        option._addToArgParser(argParser);
+      });
+    }
+    __argResults = argParser.parse(arguments);
+  }
 
   /// Traverse skips this node, because it doesn't represent a real
   /// configuration object.
@@ -745,75 +708,81 @@ class DartdocOptionSet extends DartdocOption<void> {
   void traverse(void Function(DartdocOption option) visitor) {
     _children.values.forEach((d) => d.traverse(visitor));
   }
+
+  @override
+  DartdocOption get parent =>
+      throw UnsupportedError('Root nodes have no parent');
+}
+
+/// A [DartdocOption] that only contains other [DartdocOption]s and is not an
+/// option itself.
+class DartdocOptionSet extends DartdocOption<void> {
+  DartdocOptionSet(String name, ResourceProvider resourceProvider)
+      : super(name, null, '', OptionKind.other, false, null, resourceProvider);
+
+  /// [DartdocOptionSet] always has the null value.
+  @override
+  void valueAt(Folder dir) => null;
+
+  /// Since we have no value, [_onMissing] does nothing.
+  @override
+  void _onMissing(
+      _OptionValueWithContext<void> valueWithContext, String missingFilename) {}
 }
 
 /// A [DartdocOption] that only exists as a command line argument. `--help` is a
 /// good example.
 class DartdocOptionArgOnly<T> extends DartdocOption<T>
     with _DartdocArgOption<T> {
-  String _abbr;
-  bool _hide;
-  bool _negatable;
-  bool _splitCommas;
+  @override
+  final String? abbr;
+  @override
+  final bool hide;
+  @override
+  final bool negatable;
+  @override
+  final bool splitCommas;
 
   DartdocOptionArgOnly(
       String name, T defaultsTo, ResourceProvider resourceProvider,
-      {String abbr,
+      {this.abbr,
       bool mustExist = false,
       String help = '',
-      bool hide = false,
+      this.hide = false,
       OptionKind optionIs = OptionKind.other,
-      bool negatable = false,
-      bool splitCommas})
+      this.negatable = false,
+      this.splitCommas = false})
       : super(name, defaultsTo, help, optionIs, mustExist, null,
-            resourceProvider) {
-    _hide = hide;
-    _negatable = negatable;
-    _splitCommas = splitCommas;
-    _abbr = abbr;
-  }
-
-  @override
-  String get abbr => _abbr;
-
-  @override
-  bool get hide => _hide;
-
-  @override
-  bool get negatable => _negatable;
-
-  @override
-  bool get splitCommas => _splitCommas;
+            resourceProvider);
 }
 
 /// A [DartdocOption] that works with command line arguments and
 /// `dartdoc_options` files.
 class DartdocOptionArgFile<T> extends DartdocOption<T>
     with _DartdocArgOption<T>, _DartdocFileOption<T> {
-  String _abbr;
-  bool _hide;
-  bool _negatable;
-  bool _parentDirOverridesChild;
-  bool _splitCommas;
+  @override
+  final String? abbr;
+  @override
+  final bool hide;
+  @override
+  final bool negatable;
+  @override
+  final bool parentDirOverridesChild;
+  @override
+  final bool splitCommas;
 
   DartdocOptionArgFile(
       String name, T defaultsTo, ResourceProvider resourceProvider,
-      {String abbr,
+      {this.abbr,
       bool mustExist = false,
       String help = '',
-      bool hide = false,
+      this.hide = false,
       OptionKind optionIs = OptionKind.other,
-      bool negatable = false,
-      bool parentDirOverridesChild = false,
-      bool splitCommas})
+      this.negatable = false,
+      this.parentDirOverridesChild = false,
+      this.splitCommas = false})
       : super(name, defaultsTo, help, optionIs, mustExist, null,
-            resourceProvider) {
-    _abbr = abbr;
-    _hide = hide;
-    _negatable = negatable;
-    _parentDirOverridesChild = parentDirOverridesChild;
-    _splitCommas = splitCommas;
-  }
+            resourceProvider);
 
   @override
   void _onMissing(
@@ -828,47 +797,28 @@ class DartdocOptionArgFile<T> extends DartdocOption<T>
   /// Try to find an explicit argument setting this value, but if not, fall back
   /// to files finally, the default.
   @override
-  T valueAt(Folder dir) {
+  T? valueAt(Folder dir) {
     var value = _valueAtFromArgs();
     value ??= _valueAtFromFiles(dir);
     value ??= defaultsTo;
     return value;
   }
-
-  @override
-  String get abbr => _abbr;
-
-  @override
-  bool get hide => _hide;
-
-  @override
-  bool get negatable => _negatable;
-
-  @override
-  bool get parentDirOverridesChild => _parentDirOverridesChild;
-
-  @override
-  bool get splitCommas => _splitCommas;
 }
 
 class DartdocOptionFileOnly<T> extends DartdocOption<T>
     with _DartdocFileOption<T> {
-  bool _parentDirOverridesChild;
+  @override
+  final bool parentDirOverridesChild;
 
   DartdocOptionFileOnly(
       String name, T defaultsTo, ResourceProvider resourceProvider,
       {bool mustExist = false,
       String help = '',
       OptionKind optionIs = OptionKind.other,
-      bool parentDirOverridesChild = false,
-      ConvertYamlToType<T> convertYamlToType})
+      this.parentDirOverridesChild = false,
+      ConvertYamlToType<T>? convertYamlToType})
       : super(name, defaultsTo, help, optionIs, mustExist, convertYamlToType,
-            resourceProvider) {
-    _parentDirOverridesChild = parentDirOverridesChild;
-  }
-
-  @override
-  bool get parentDirOverridesChild => _parentDirOverridesChild;
+            resourceProvider);
 }
 
 /// Implements checking for options contained in dartdoc.yaml.
@@ -905,18 +855,18 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
 
   /// Searches for a value in configuration files relative to [dir], and if not
   /// found, returns [defaultsTo].
-  T valueAt(Folder dir) {
+  T? valueAt(Folder dir) {
     return _valueAtFromFiles(dir) ?? defaultsTo;
   }
 
-  final Map<String, T> __valueAtFromFiles = {};
+  final Map<String, T?> __valueAtFromFiles = {};
 
   // The value of this option from files will not change unless files are
   // modified during execution (not allowed in Dartdoc).
-  T _valueAtFromFiles(Folder dir) {
+  T? _valueAtFromFiles(Folder dir) {
     var key = resourceProvider.pathContext.canonicalize(dir.path);
     if (!__valueAtFromFiles.containsKey(key)) {
-      _OptionValueWithContext<T> valueWithContext;
+      _OptionValueWithContext<T>? valueWithContext;
       if (parentDirOverridesChild) {
         valueWithContext = _valueAtFromFilesLastFound(dir);
       } else {
@@ -929,8 +879,8 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
 
   /// Searches all dartdoc_options files through parent directories, starting at
   /// [dir], for the option and returns one once found.
-  _OptionValueWithContext<T> _valueAtFromFilesFirstFound(Folder folder) {
-    _OptionValueWithContext<T> value;
+  _OptionValueWithContext<T>? _valueAtFromFilesFirstFound(Folder folder) {
+    _OptionValueWithContext<T>? value;
     for (var dir in folder.withAncestors) {
       value = _valueAtFromFile(dir);
       if (value != null) break;
@@ -941,8 +891,8 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
   /// Searches all dartdoc_options files for the option, and returns the value
   /// in the top-most parent directory `dartdoc_options.yaml` file it is
   /// mentioned in.
-  _OptionValueWithContext<T> _valueAtFromFilesLastFound(Folder folder) {
-    _OptionValueWithContext<T> value;
+  _OptionValueWithContext<T>? _valueAtFromFilesLastFound(Folder folder) {
+    _OptionValueWithContext<T>? value;
     for (var dir in folder.withAncestors) {
       var tmpValue = _valueAtFromFile(dir);
       if (tmpValue != null) value = tmpValue;
@@ -952,16 +902,16 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
 
   /// Returns null if not set in the YAML file in this directory (or its
   /// parents).
-  _OptionValueWithContext<T> _valueAtFromFile(Folder dir) {
+  _OptionValueWithContext<T>? _valueAtFromFile(Folder dir) {
     var yamlFileData = _yamlAtDirectory(dir);
     var contextPath = yamlFileData.canonicalDirectoryPath;
-    Object yamlData = yamlFileData.data ?? {};
+    Object yamlData = yamlFileData.data;
     for (var key in keys) {
       if (yamlData is Map && !yamlData.containsKey(key)) return null;
       yamlData = (yamlData as Map)[key] ?? {};
     }
 
-    Object returnData;
+    Object? returnData;
     if (_isListString) {
       if (yamlData is YamlList) {
         returnData = [
@@ -969,6 +919,7 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
         ];
       }
     } else if (yamlData is YamlMap) {
+      var convertYamlToType = _convertYamlToType;
       // TODO(jcollins-g): This special casing is unfortunate.  Consider
       // a refactor to extract yaml data conversion into closures 100% of the
       // time or find a cleaner way to do this.
@@ -976,8 +927,8 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
       // A refactor probably would integrate resolvedValue for
       // _OptionValueWithContext into the return data here, and would not have
       // that be separate.
-      if (_isMapString && _convertYamlToType == null) {
-        _convertYamlToType = (YamlMap yamlMap, String canonicalYamlPath,
+      if (_isMapString && convertYamlToType == null) {
+        convertYamlToType = (YamlMap yamlMap, String canonicalYamlPath,
             ResourceProvider resourceProvider) {
           var returnData = <String, String>{};
           for (var entry in yamlMap.entries) {
@@ -986,15 +937,15 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
           return returnData as T;
         };
       }
-      if (_convertYamlToType == null) {
+      if (convertYamlToType == null) {
         throw DartdocOptionError(
             'Unable to convert yaml to type for option: $fieldName, method not '
             'defined');
       }
       var canonicalDirectoryPath =
           resourceProvider.pathContext.canonicalize(contextPath);
-      returnData = _convertYamlToType(
-          yamlData, canonicalDirectoryPath, resourceProvider);
+      returnData =
+          convertYamlToType(yamlData, canonicalDirectoryPath, resourceProvider);
     } else if (_isDouble) {
       if (yamlData is num) {
         returnData = yamlData.toDouble();
@@ -1018,7 +969,7 @@ abstract class _DartdocFileOption<T> implements DartdocOption<T> {
       var canonicalPath =
           resourceProvider.pathContext.canonicalize(folder.path);
       if (_yamlAtCanonicalPathCache.containsKey(canonicalPath)) {
-        yamlData = _yamlAtCanonicalPathCache[canonicalPath];
+        yamlData = _yamlAtCanonicalPathCache[canonicalPath]!;
         break;
       }
       canonicalPaths.add(canonicalPath);
@@ -1054,12 +1005,12 @@ abstract class _DartdocArgOption<T> implements DartdocOption<T> {
 
   /// For [ArgParser], set to a single character to have a short version of the
   /// command line argument.
-  String get abbr;
+  String? get abbr;
 
   /// valueAt for arguments ignores the [dir] parameter and only uses command
   /// line arguments and the current working directory to resolve the result.
   @override
-  T valueAt(Folder dir) => _valueAtFromArgs() ?? defaultsTo;
+  T? valueAt(Folder dir) => _valueAtFromArgs() ?? defaultsTo;
 
   /// For passing in to [int.parse] and [double.parse] `onError'.
   void _throwErrorForTypes(String value) {
@@ -1070,6 +1021,9 @@ abstract class _DartdocArgOption<T> implements DartdocOption<T> {
       example = '32';
     } else if (_isDouble) {
       example = '0.76';
+    } else {
+      throw UnimplementedError(
+          'Type for $name is not implemented in $_throwErrorForTypes');
     }
     throw DartdocOptionError(
         'Invalid argument value: --$argName, set to "$value", must be a '
@@ -1077,7 +1031,7 @@ abstract class _DartdocArgOption<T> implements DartdocOption<T> {
   }
 
   /// Returns null if no argument was given on the command line.
-  T _valueAtFromArgs() {
+  T? _valueAtFromArgs() {
     var valueWithContext = _valueAtFromArgsWithContext();
     return _handlePathsInContext(valueWithContext);
   }
@@ -1098,7 +1052,7 @@ abstract class _DartdocArgOption<T> implements DartdocOption<T> {
   /// the [argParser] and the working directory from [_directoryCurrent].
   ///
   /// Throws [UnsupportedError] if [T] is not a supported type.
-  _OptionValueWithContext<T> _valueAtFromArgsWithContext() {
+  _OptionValueWithContext<T>? _valueAtFromArgsWithContext() {
     if (!_argResults.wasParsed(argName)) return null;
 
     T retval;
@@ -1145,7 +1099,8 @@ abstract class _DartdocArgOption<T> implements DartdocOption<T> {
     final camelCaseRegexp = RegExp(r'([a-z])([A-Z])(?=([a-z]))');
     argName = argName.replaceAllMapped(camelCaseRegexp, (Match m) {
       var before = m.group(1);
-      var after = m.group(2).toLowerCase();
+      // Group 2 is not optional.
+      var after = m.group(2)!.toLowerCase();
       return '$before-$after';
     });
     return argName;
@@ -1155,14 +1110,14 @@ abstract class _DartdocArgOption<T> implements DartdocOption<T> {
   /// [ArgParser.addFlag], [ArgParser.addOption], or [ArgParser.addMultiOption]
   /// as appropriate for [T].
   @override
-  void _onAdd() {
+  void _addToArgParser(ArgParser argParser) {
     if (_isBool) {
       argParser.addFlag(argName,
           abbr: abbr,
           defaultsTo: defaultsTo as bool,
           help: help,
           hide: hide,
-          negatable: negatable ?? false);
+          negatable: negatable);
     } else if (_isInt || _isDouble || _isString) {
       argParser.addOption(argName,
           abbr: abbr,
@@ -1212,29 +1167,25 @@ class DartdocOptionContext extends DartdocOptionContextBase
   @override
   final DartdocOptionSet optionSet;
   @override
-  Folder context;
+  final Folder context;
 
   // TODO(jcollins-g): Allow passing in structured data to initialize a
   // [DartdocOptionContext]'s arguments instead of having to parse strings
   // via optionSet.
   DartdocOptionContext(this.optionSet, Resource contextLocation,
-      ResourceProvider resourceProvider) {
-    assert(contextLocation != null);
-    context = resourceProvider.getFolder(resourceProvider.pathContext
-        .canonicalize(contextLocation is File
-            ? contextLocation.parent2.path
-            : contextLocation.path));
-  }
+      ResourceProvider resourceProvider)
+      : context = resourceProvider.getFolder(resourceProvider.pathContext
+            .canonicalize(contextLocation is File
+                ? contextLocation.parent2.path
+                : contextLocation.path));
 
   /// Build a DartdocOptionContext via the 'inputDir' command line option.
   DartdocOptionContext.fromDefaultContextLocation(
-      this.optionSet, ResourceProvider resourceProvider) {
-    var current = resourceProvider.pathContext.current;
-    String inputDir =
-        optionSet['inputDir'].valueAt(resourceProvider.getFolder(current)) ??
-            current;
-    context = resourceProvider.getFolder(inputDir);
-  }
+      this.optionSet, ResourceProvider resourceProvider)
+      : context = resourceProvider.getFolder(optionSet['inputDir'].valueAt(
+                resourceProvider
+                    .getFolder(resourceProvider.pathContext.current)) ??
+            resourceProvider.pathContext.current);
 
   /// Build a DartdocOptionContext from an analyzer element (using its source
   /// location).
@@ -1282,13 +1233,9 @@ class DartdocOptionContext extends DartdocOptionContextBase
   String get examplePathPrefix =>
       optionSet['examplePathPrefix'].valueAt(context);
 
-  /// A memoized calculation of exclusions.
   // TODO(srawlins): This memoization saved a lot of time in unit testing, but
   // is the first value in this class to be memoized. Memoize others?
-  /*late final*/ List<String> _exclude;
-
-  List<String> get exclude =>
-      _exclude ??= optionSet['exclude'].valueAt(context);
+  late final List<String> exclude = optionSet['exclude'].valueAt(context);
 
   List<String> get excludePackages =>
       optionSet['excludePackages'].valueAt(context);
@@ -1388,6 +1335,7 @@ Future<List<DartdocOption>> createDartdocOptions(
             'in the current package or "include-external"',
         negatable: true),
     DartdocOptionArgFile<List<String>>('categoryOrder', [], resourceProvider,
+        splitCommas: true,
         help: 'A list of categories (not package names) to place first when '
             "grouping symbols on dartdoc's sidebar. Unmentioned categories are "
             'sorted after these.'),
@@ -1421,7 +1369,7 @@ Future<List<DartdocOption>> createDartdocOptions(
       return [];
     }, resourceProvider,
         help: 'Remove text from libraries with the following names.'),
-    DartdocOptionArgFile<String>('examplePathPrefix', null, resourceProvider,
+    DartdocOptionArgFile<String?>('examplePathPrefix', null, resourceProvider,
         optionIs: OptionKind.dir,
         help: 'Prefix for @example paths.\n(defaults to the project root)',
         mustExist: true),
@@ -1456,8 +1404,7 @@ Future<List<DartdocOption>> createDartdocOptions(
         negatable: true),
     DartdocOptionArgFile<List<String>>('include', [], resourceProvider,
         help: 'Library names to generate docs for.', splitCommas: true),
-    DartdocOptionArgFile<List<String>>(
-        'includeExternal', null, resourceProvider,
+    DartdocOptionArgFile<List<String>>('includeExternal', [], resourceProvider,
         optionIs: OptionKind.file,
         help:
             'Additional (external) dart files to include; use "dir/fileName", '
@@ -1507,14 +1454,18 @@ Future<List<DartdocOption>> createDartdocOptions(
           // Prefer SDK check first, then pub cache check.
           var inSdk = packageMeta
               .sdkType(option.parent.parent['flutterRoot'].valueAt(dir));
+          // Analyzer may be confused because package_meta still needs
+          // migrating.  It can definitely return null.
+          // ignore: unnecessary_null_comparison
           if (inSdk != null) {
             Map<String, String> sdks = option.parent['sdks'].valueAt(dir);
-            if (sdks.containsKey(inSdk)) return sdks[inSdk];
+            if (sdks.containsKey(inSdk)) return sdks[inSdk]!;
           }
           var hostedAt = packageMeta.hostedAt;
+          // ignore: unnecessary_null_comparison
           if (hostedAt != null) {
             Map<String, String> hostMap = option.parent['hosted'].valueAt(dir);
-            if (hostMap.containsKey(hostedAt)) return hostMap[hostedAt];
+            if (hostMap.containsKey(hostedAt)) return hostMap[hostedAt]!;
           }
           return '';
         }, resourceProvider, help: 'Url to use for this particular package.'),
@@ -1534,6 +1485,7 @@ Future<List<DartdocOption>> createDartdocOptions(
       'packageMeta',
       (DartdocSyntheticOption<PackageMeta> option, Folder dir) {
         var packageMeta = packageMetaProvider.fromDir(dir);
+        // ignore: unnecessary_null_comparison
         if (packageMeta == null) {
           throw DartdocOptionError(
               'Unable to determine package for directory: ${dir.path}');
@@ -1543,17 +1495,18 @@ Future<List<DartdocOption>> createDartdocOptions(
       resourceProvider,
     ),
     DartdocOptionArgOnly<List<String>>('packageOrder', [], resourceProvider,
+        splitCommas: true,
         help:
             'A list of package names to place first when grouping libraries in '
             'packages. Unmentioned packages are sorted after these.'),
     DartdocOptionArgOnly<bool>('sdkDocs', false, resourceProvider,
         help: 'Generate ONLY the docs for the Dart SDK.'),
-    DartdocOptionArgSynth<String>('sdkDir',
-        (DartdocSyntheticOption<String> option, Folder dir) {
+    DartdocOptionArgSynth<String?>('sdkDir',
+        (DartdocSyntheticOption<String?> option, Folder dir) {
       if (!(option.parent['sdkDocs'].valueAt(dir) as bool) &&
           (option.root['topLevelPackageMeta'].valueAt(dir) as PackageMeta)
               .requiresFlutter) {
-        String flutterRoot = option.root['flutterRoot'].valueAt(dir);
+        String? flutterRoot = option.root['flutterRoot'].valueAt(dir);
         if (flutterRoot == null) {
           // For now, return null. An error is reported in
           // [PackageBuilder.buildPackageGraph].
@@ -1574,6 +1527,7 @@ Future<List<DartdocOption>> createDartdocOptions(
         (DartdocSyntheticOption<PackageMeta> option, Folder dir) {
       var packageMeta = packageMetaProvider.fromDir(
           resourceProvider.getFolder(option.parent['inputDir'].valueAt(dir)));
+      // ignore: unnecessary_null_comparison
       if (packageMeta == null) {
         throw DartdocOptionError(
             'Unable to generate documentation: no package found');
diff --git a/lib/src/generator/templates.runtime_renderers.dart b/lib/src/generator/templates.runtime_renderers.dart
index 476d4695a1..578eaae7fc 100644
--- a/lib/src/generator/templates.runtime_renderers.dart
+++ b/lib/src/generator/templates.runtime_renderers.dart
@@ -14834,6 +14834,7 @@ const _invisibleGetters = {
     'runtimeType',
     'optionSet',
     'context',
+    'exclude',
     'allowTools',
     'ambiguousReexportScorerMinConfidence',
     'autoIncludeDependencies',
@@ -14841,7 +14842,6 @@ const _invisibleGetters = {
     'categories',
     'dropTextFrom',
     'examplePathPrefix',
-    'exclude',
     'excludePackages',
     'enhancedReferenceLookup',
     'flutterRoot',
diff --git a/lib/src/logging.dart b/lib/src/logging.dart
index b56a8d39c1..6a673a0cd5 100644
--- a/lib/src/logging.dart
+++ b/lib/src/logging.dart
@@ -145,7 +145,7 @@ Future<List<DartdocOption<Object>>> createLoggingOptions(
         negatable: true),
     DartdocOptionArgSynth<bool>('quiet',
         (DartdocSyntheticOption<Object> option, Folder dir) {
-      if (option.root['generateDocs']?.valueAt(dir) == false) {
+      if (option.parent['generateDocs'].valueAt(dir) == false) {
         return true;
       }
       return false;
diff --git a/lib/src/warnings.dart b/lib/src/warnings.dart
index f34b790e72..acd4aa272a 100644
--- a/lib/src/warnings.dart
+++ b/lib/src/warnings.dart
@@ -41,23 +41,28 @@ Future<List<DartdocOption<Object>>> createPackageWarningOptions(
     // packages they don't control.
     DartdocOptionArgOnly<List<String>>(
         'allowWarningsInPackages', null, resourceProvider,
+        splitCommas: true,
         help:
             'Package names to display warnings for (ignore all others if set).'),
     DartdocOptionArgOnly<List<String>>(
         'allowErrorsInPackages', null, resourceProvider,
+        splitCommas: true,
         help: 'Package names to display errors for (ignore all others if set)'),
     DartdocOptionArgOnly<List<String>>(
         'ignoreWarningsInPackages', null, resourceProvider,
+        splitCommas: true,
         help: 'Package names to ignore warnings for.  Takes priority over '
             'allow-warnings-in-packages'),
     DartdocOptionArgOnly<List<String>>(
         'ignoreErrorsInPackages', null, resourceProvider,
+        splitCommas: true,
         help: 'Package names to ignore errors for. Takes priority over '
             'allow-errors-in-packages'),
     // Options for globally enabling/disabling warnings and errors across
     // packages.  Loaded from dartdoc_options.yaml, but command line arguments
     // will override.
     DartdocOptionArgFile<List<String>>('errors', null, resourceProvider,
+        splitCommas: true,
         help: 'Additional warning names to force as errors.  Specify an empty '
                 'list to force defaults (overriding dartdoc_options.yaml)\nDefaults:\n' +
             (packageWarningDefinitions.values
@@ -68,6 +73,7 @@ Future<List<DartdocOption<Object>>> createPackageWarningOptions(
                 .map((d) => '   ${d.warningName}: ${d.shortHelp}')
                 .join('\n')),
     DartdocOptionArgFile<List<String>>('ignore', null, resourceProvider,
+        splitCommas: true,
         help: 'Additional warning names to ignore.  Specify an empty list to '
                 'force defaults (overriding dartdoc_options.yaml).\nDefaults:\n' +
             (packageWarningDefinitions.values
@@ -78,6 +84,7 @@ Future<List<DartdocOption<Object>>> createPackageWarningOptions(
                 .map((d) => '   ${d.warningName}: ${d.shortHelp}')
                 .join('\n')),
     DartdocOptionArgFile<List<String>>('warnings', null, resourceProvider,
+        splitCommas: true,
         help:
             'Additional warning names to show as warnings (instead of error or '
                     'ignore, if not warning by default).\nDefaults:\n' +
diff --git a/test/dartdoc_options_test.dart b/test/dartdoc_options_test.dart
index 95f7d38bab..3f2a540962 100644
--- a/test/dartdoc_options_test.dart
+++ b/test/dartdoc_options_test.dart
@@ -43,10 +43,10 @@ class ConvertedOption {
 void main() {
   var resourceProvider = pubPackageMetaProvider.resourceProvider;
 
-  DartdocOptionSet dartdocOptionSetFiles;
-  DartdocOptionSet dartdocOptionSetArgs;
-  DartdocOptionSet dartdocOptionSetAll;
-  DartdocOptionSet dartdocOptionSetSynthetic;
+  DartdocOptionRoot dartdocOptionSetFiles;
+  DartdocOptionRoot dartdocOptionSetArgs;
+  DartdocOptionRoot dartdocOptionSetAll;
+  DartdocOptionRoot dartdocOptionSetSynthetic;
   Folder tempDir;
   Folder firstDir;
   Folder secondDir;
@@ -59,7 +59,7 @@ void main() {
   File firstExisting;
 
   setUpAll(() {
-    dartdocOptionSetSynthetic = DartdocOptionSet('dartdoc', resourceProvider);
+    dartdocOptionSetSynthetic = DartdocOptionRoot('dartdoc', resourceProvider);
     dartdocOptionSetSynthetic.add(
         DartdocOptionArgFile<int>('mySpecialInteger', 91, resourceProvider));
     dartdocOptionSetSynthetic.add(
@@ -86,7 +86,7 @@ void main() {
       return (option.root['vegetableLoader'].valueAt(dir) as List).first;
     }, resourceProvider, optionIs: OptionKind.file));
 
-    dartdocOptionSetFiles = DartdocOptionSet('dartdoc', resourceProvider);
+    dartdocOptionSetFiles = DartdocOptionRoot('dartdoc', resourceProvider);
     dartdocOptionSetFiles.add(DartdocOptionFileOnly<List<String>>(
         'categoryOrder', [], resourceProvider));
     dartdocOptionSetFiles
@@ -122,7 +122,7 @@ void main() {
       convertYamlToType: ConvertedOption.fromYamlMap,
     ));
 
-    dartdocOptionSetArgs = DartdocOptionSet('dartdoc', resourceProvider);
+    dartdocOptionSetArgs = DartdocOptionRoot('dartdoc', resourceProvider);
     dartdocOptionSetArgs.add(DartdocOptionArgOnly<bool>(
         'cauliflowerSystem', false, resourceProvider));
     dartdocOptionSetArgs.add(DartdocOptionArgOnly<String>(
@@ -152,7 +152,7 @@ void main() {
         'unimportantFile', 'whatever', resourceProvider,
         optionIs: OptionKind.file));
 
-    dartdocOptionSetAll = DartdocOptionSet('dartdoc', resourceProvider);
+    dartdocOptionSetAll = DartdocOptionRoot('dartdoc', resourceProvider);
     dartdocOptionSetAll.add(DartdocOptionArgFile<List<String>>(
         'categoryOrder', [], resourceProvider));
     dartdocOptionSetAll.add(
diff --git a/test/documentation_comment_test.dart b/test/documentation_comment_test.dart
index 1650f759d9..f297926ec7 100644
--- a/test/documentation_comment_test.dart
+++ b/test/documentation_comment_test.dart
@@ -53,7 +53,7 @@ void main() {
         sdkFolder,
         defaultSdk: mockSdk,
       );
-      var optionSet = await DartdocOptionSet.fromOptionGenerators(
+      var optionSet = await DartdocOptionRoot.fromOptionGenerators(
           'dartdoc', [createDartdocOptions], packageMetaProvider);
       optionSet.parseArguments([]);
       packageConfigProvider = FakePackageConfigProvider();
diff --git a/test/end2end/dartdoc_test.dart b/test/end2end/dartdoc_test.dart
index 62f961e1cc..047dc158d8 100644
--- a/test/end2end/dartdoc_test.dart
+++ b/test/end2end/dartdoc_test.dart
@@ -49,7 +49,7 @@ final Folder _testPackageExperiments =
 /// the '--input' flag.
 Future<DartdocGeneratorOptionContext> _generatorContextFromArgv(
     List<String> argv) async {
-  var optionSet = await DartdocOptionSet.fromOptionGenerators(
+  var optionSet = await DartdocOptionRoot.fromOptionGenerators(
       'dartdoc',
       [
         createDartdocOptions,
@@ -73,8 +73,10 @@ void main() {
     Folder tempDir;
 
     setUpAll(() async {
-      var optionSet = await DartdocOptionSet.fromOptionGenerators(
-          'dartdoc', [createLoggingOptions], pubPackageMetaProvider);
+      var optionSet = await DartdocOptionRoot.fromOptionGenerators(
+          'dartdoc',
+          [createDartdocProgramOptions, createLoggingOptions],
+          pubPackageMetaProvider);
       optionSet.parseArguments([]);
       startLogging(DartdocLoggingOptionContext(
           optionSet,
diff --git a/test/mustachio/renderers_output_test.dart b/test/mustachio/renderers_output_test.dart
index 39c7dbf604..5f0071342f 100644
--- a/test/mustachio/renderers_output_test.dart
+++ b/test/mustachio/renderers_output_test.dart
@@ -21,7 +21,7 @@ import 'package:test/test.dart';
 /// the '--input' flag.
 Future<DartdocGeneratorOptionContext> _generatorContextFromArgv(
     List<String> argv) async {
-  var optionSet = await DartdocOptionSet.fromOptionGenerators(
+  var optionSet = await DartdocOptionRoot.fromOptionGenerators(
       'dartdoc',
       [
         createDartdocOptions,
diff --git a/test/package_test.dart b/test/package_test.dart
index 4c44da5178..183e00bb35 100644
--- a/test/package_test.dart
+++ b/test/package_test.dart
@@ -40,7 +40,7 @@ void main() {
     resourceProvider = packageMetaProvider.resourceProvider;
     sdkFolder = packageMetaProvider.defaultSdkDir;
 
-    optionSet = await DartdocOptionSet.fromOptionGenerators(
+    optionSet = await DartdocOptionRoot.fromOptionGenerators(
         'dartdoc', [createDartdocOptions], packageMetaProvider);
     packageConfigProvider = utils.getTestPackageConfigProvider(sdkFolder.path);
   });
diff --git a/test/src/utils.dart b/test/src/utils.dart
index 3636ddf3f3..46b0e60be7 100644
--- a/test/src/utils.dart
+++ b/test/src/utils.dart
@@ -36,7 +36,7 @@ final Folder testPackageToolError = _resourceProvider.getFolder(_pathContext
 /// [DartdocOptionSet] based on the current working directory.
 Future<DartdocOptionContext> contextFromArgv(
     List<String> argv, PackageMetaProvider packageMetaProvider) async {
-  var optionSet = await DartdocOptionSet.fromOptionGenerators(
+  var optionSet = await DartdocOptionRoot.fromOptionGenerators(
       'dartdoc', [createDartdocOptions], packageMetaProvider);
   optionSet.parseArguments(argv);
   return DartdocOptionContext.fromDefaultContextLocation(
diff --git a/test/warnings_test.dart b/test/warnings_test.dart
index 6f63e6b497..f4f571abf9 100644
--- a/test/warnings_test.dart
+++ b/test/warnings_test.dart
@@ -56,7 +56,7 @@ dartdoc:
   });
 
   setUp(() async {
-    optionSet = await DartdocOptionSet.fromOptionGenerators(
+    optionSet = await DartdocOptionRoot.fromOptionGenerators(
         'dartdoc', [createDartdocOptions], pubPackageMetaProvider);
   });