Migrate more libraries to NNBD (#2827)

* migrate category

* Migrate model_comment_reference and the parser

* Fix test failure

Author: jcollins-g

lib/src/comment_references/model_comment_reference.dart

@@ -3,8 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 //
 
-// @dart=2.9
-
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
@@ -19,7 +17,7 @@ abstract class ModelCommentReference {
   bool get hasConstructorHint;
   bool get hasCallableHint;
   List<String> get referenceBy;
-  Element get staticElement;
+  Element? get staticElement;
 
   /// Construct a [ModelCommentReference] using the analyzer AST.
   factory ModelCommentReference(
@@ -35,45 +33,47 @@ abstract class ModelCommentReference {
 /// information needed for Dartdoc.  Drops link to the [CommentReference]
 /// and [ResourceProvider] after construction.
 class _ModelCommentReferenceImpl implements ModelCommentReference {
-  bool _allowUnnamedConstructor;
-
   void _initAllowCache() {
     var referencePieces = parsed.whereType<IdentifierNode>().toList();
     _allowUnnamedConstructor = false;
     _allowUnnamedConstructorParameter = false;
     if (referencePieces.length >= 2) {
-      IdentifierNode nodeLast;
-      for (var f in referencePieces) {
-        if (f.text == nodeLast?.text) {
-          if (identical(referencePieces.last, f)) {
+      for (var i = 0; i <= referencePieces.length - 2; i++) {
+        if (referencePieces[i].text == referencePieces[i + 1].text) {
+          if (i + 2 == referencePieces.length) {
+            // This looks like an old-style reference to an unnamed
+            // constructor, e.g. [lib_name.C.C].
             _allowUnnamedConstructor = true;
           } else {
+            // This could be a reference to a parameter or type parameter of
+            // an unnamed/new-declared constructor.
             _allowUnnamedConstructorParameter = true;
           }
         }
-        nodeLast = f;
       }
-      if (referencePieces.last.text == 'new') {
+      // e.g. [C.new], which may be the unnamed constructor
+      if (referencePieces.isNotEmpty && referencePieces.last.text == 'new') {
         _allowUnnamedConstructor = true;
       }
     }
   }
 
+  bool? _allowUnnamedConstructor;
   @override
   bool get allowUnnamedConstructor {
     if (_allowUnnamedConstructor == null) {
       _initAllowCache();
     }
-    return _allowUnnamedConstructor;
+    return _allowUnnamedConstructor!;
   }
 
-  bool _allowUnnamedConstructorParameter;
+  bool? _allowUnnamedConstructorParameter;
   @override
   bool get allowUnnamedConstructorParameter {
     if (_allowUnnamedConstructorParameter == null) {
       _initAllowCache();
     }
-    return _allowUnnamedConstructorParameter;
+    return _allowUnnamedConstructorParameter!;
   }
 
   @override
@@ -96,7 +96,7 @@ class _ModelCommentReferenceImpl implements ModelCommentReference {
       .toList(growable: false);
 
   @override
-  final Element staticElement;
+  final Element? staticElement;
 
   _ModelCommentReferenceImpl(
       CommentReference ref, ResourceProvider resourceProvider)
@@ -120,7 +120,6 @@ class _ModelCommentReferenceImpl implements ModelCommentReference {
         .substring(ref.offset - token.offset, ref.end - token.offset);
   }
 
-  List<CommentReferenceNode> _parsed;
-  List<CommentReferenceNode> get parsed =>
-      _parsed ??= CommentReferenceParser(codeRef).parse();
+  late final List<CommentReferenceNode> parsed =
+      CommentReferenceParser(codeRef).parse();
 }

lib/src/comment_references/parser.dart

@@ -3,8 +3,6 @@
 // BSD-style license that can be found in the LICENSE file.
 //
 
-// @dart=2.9
-
 import 'package:charcode/charcode.dart';
 import 'package:meta/meta.dart';
 
@@ -52,7 +50,7 @@ class StringTrie {
     var matchChar = toMatch.codeUnitAt(index);
     if (children.containsKey(matchChar)) {
       lastValid = valid ? index : lastValid;
-      return children[matchChar].match(toMatch, index + 1, lastValid);
+      return children[matchChar]!.match(toMatch, index + 1, lastValid);
     }
     return valid ? index : lastValid;
   }
@@ -61,22 +59,19 @@ class StringTrie {
     var currentTrie = this;
     for (var i in toAdd.codeUnits) {
       currentTrie.children.putIfAbsent(i, () => StringTrie());
-      currentTrie = currentTrie.children[i];
+      currentTrie = currentTrie.children[i]!;
     }
     currentTrie.valid = true;
   }
 }
 
-StringTrie _operatorParseTrie;
-StringTrie get operatorParseTrie {
-  if (_operatorParseTrie == null) {
-    _operatorParseTrie = StringTrie();
-    for (var name in operatorNames.keys) {
-      _operatorParseTrie.addWord(name);
-    }
+late final StringTrie operatorParseTrie = () {
+  var _operatorParseTrie = StringTrie();
+  for (var name in operatorNames.keys) {
+    _operatorParseTrie.addWord(name);
   }
   return _operatorParseTrie;
-}
+}();
 
 /// A parser for comment references.
 // TODO(jcollins-g): align with [CommentReference] from analyzer AST.
@@ -114,7 +109,7 @@ class CommentReferenceParser {
       return [];
     }
     if (prefixResult.type == _PrefixResultType.parsedConstructorHint) {
-      children.add(prefixResult.node);
+      children.add(prefixResult.node!);
     }
     // [_PrefixResultType.junk] and [_PrefixResultType.missing] we can skip.
 
@@ -130,13 +125,13 @@ class CommentReferenceParser {
         break;
       } else if (identifierResult.type ==
           _IdentifierResultType.parsedIdentifier) {
-        children.add(identifierResult.node);
+        children.add(identifierResult.node!);
         var typeVariablesResult = _parseTypeVariables();
         if (typeVariablesResult.type == _TypeVariablesResultType.endOfFile) {
           break;
         } else if (typeVariablesResult.type ==
             _TypeVariablesResultType.parsedTypeVariables) {
-          children.add(typeVariablesResult.node);
+          children.add(typeVariablesResult.node!);
         } else {
           assert(typeVariablesResult.type ==
               _TypeVariablesResultType.notTypeVariables);
@@ -154,7 +149,7 @@ class CommentReferenceParser {
       // Invalid trailing junk; reject the reference.
       return [];
     } else if (suffixResult.type == _SuffixResultType.parsedCallableHint) {
-      children.add(suffixResult.node);
+      children.add(suffixResult.node!);
     }
 
     // [_SuffixResultType.junk] or [_SuffixResultType.missing] we can skip.
@@ -209,7 +204,7 @@ class CommentReferenceParser {
   /// Advances the index forward to the end of the operator if one is
   /// present and returns the operator's name.  Otherwise, leaves _index
   /// unchanged and returns null.
-  String _tryParseOperator() {
+  String? _tryParseOperator() {
     var tryIndex = _index;
     if (tryIndex + _operatorKeyword.length < codeRef.length &&
         codeRef.substring(tryIndex, tryIndex + _operatorKeyword.length) ==
@@ -318,7 +313,6 @@ class CommentReferenceParser {
   bool _tryMatchLiteral(String characters,
       {bool acceptTrailingWhitespace = true,
       bool requireTrailingNonidentifier = false}) {
-    assert(acceptTrailingWhitespace != null);
     if (characters.length + _index > _referenceLength) return false;
     int startIndex;
     for (startIndex = _index;
@@ -388,7 +382,7 @@ enum _PrefixResultType {
 class _PrefixParseResult {
   final _PrefixResultType type;
 
-  final CommentReferenceNode node;
+  final CommentReferenceNode? node;
 
   const _PrefixParseResult._(this.type, this.node);
 
@@ -416,7 +410,7 @@ enum _IdentifierResultType {
 class _IdentifierParseResult {
   final _IdentifierResultType type;
 
-  final IdentifierNode node;
+  final IdentifierNode? node;
 
   const _IdentifierParseResult._(this.type, this.node);
 
@@ -440,7 +434,7 @@ enum _TypeVariablesResultType {
 class _TypeVariablesParseResult {
   final _TypeVariablesResultType type;
 
-  final TypeVariablesNode node;
+  final TypeVariablesNode? node;
 
   const _TypeVariablesParseResult._(this.type, this.node);
 
@@ -467,7 +461,7 @@ enum _SuffixResultType {
 class _SuffixParseResult {
   final _SuffixResultType type;
 
-  final CommentReferenceNode node;
+  final CommentReferenceNode? node;
 
   const _SuffixParseResult._(this.type, this.node);
 

lib/src/model/category.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
-
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:dartdoc/src/comment_references/model_comment_reference.dart';
@@ -88,14 +86,13 @@ class Category extends Nameable
   }
 
   @override
-  // TODO(jcollins-g): make [Category] a [Warnable]?
-  Warnable get enclosingElement => null;
+  Warnable? get enclosingElement => null;
 
   @override
-  Element get element => null;
+  Element? get element => null;
 
   @override
-  String get name => categoryDefinition?.displayName ?? _name;
+  String get name => categoryDefinition.displayName;
 
   @override
   String get sortKey => _name;
@@ -110,22 +107,18 @@ class Category extends Nameable
   PackageGraph get packageGraph => package.packageGraph;
 
   @override
-  Library get canonicalLibrary => null;
+  Library get canonicalLibrary =>
+      throw UnimplementedError('Categories can not have associated libraries.');
 
   @override
   List<Locatable> get documentationFrom => [this];
 
   @override
   DocumentLocation get documentedWhere => package.documentedWhere;
 
-  bool _isDocumented;
-
   @override
-  bool get isDocumented {
-    _isDocumented ??= documentedWhere != DocumentLocation.missing &&
-        documentationFile != null;
-    return _isDocumented;
-  }
+  late final bool isDocumented =
+      documentedWhere != DocumentLocation.missing && documentationFile != null;
 
   @override
   String get fullyQualifiedName => name;
@@ -135,41 +128,34 @@ class Category extends Nameable
   String get filePath => 'topics/$name-topic.$_fileType';
 
   @override
-  String get href => isCanonical ? '${package.baseHref}$filePath' : null;
+  String? get href => isCanonical ? '${package.baseHref}$filePath' : null;
 
   String get categoryLabel => _categoryRenderer.renderCategoryLabel(this);
 
   String get linkedName => _categoryRenderer.renderLinkedName(this);
 
-  int _categoryIndex;
-
   /// The position in the container order for this category.
-  int get categoryIndex {
-    _categoryIndex ??= package.categories.indexOf(this);
-    return _categoryIndex;
-  }
+  late final int categoryIndex = package.categories.indexOf(this);
 
-  CategoryDefinition get categoryDefinition =>
-      config.categories.categoryDefinitions[sortKey];
+  late final CategoryDefinition categoryDefinition =
+      config.categories.categoryDefinitions[sortKey] ??
+          CategoryDefinition(_name, null, null);
 
   @override
-  bool get isCanonical => categoryDefinition != null;
+  bool get isCanonical =>
+      config.categories.categoryDefinitions.containsKey(sortKey);
 
   @override
   String get kind => 'Topic';
 
-  File _documentationFile;
-
   @override
-  File get documentationFile {
-    if (_documentationFile == null) {
-      if (categoryDefinition?.documentationMarkdown != null) {
-        _documentationFile = _config.resourceProvider
-            .getFile(categoryDefinition.documentationMarkdown);
-      }
+  late final File? documentationFile = () {
+    var documentationMarkdown = categoryDefinition.documentationMarkdown;
+    if (documentationMarkdown != null) {
+      return _config.resourceProvider.getFile(documentationMarkdown);
     }
-    return _documentationFile;
-  }
+    return null;
+  }();
 
   @override
   Iterable<Class> get classes => _classes;

lib/src/warnings.dart

@@ -283,9 +283,9 @@ const Map<PackageWarning, PackageWarningDefinition> packageWarningDefinitions =
 /// with an analyzer [element].
 mixin Warnable implements Canonicalization, CommentReferable {
   @override
-  Element get element;
+  Element? get element;
 
-  Warnable get enclosingElement;
+  Warnable? get enclosingElement;
 
   Package get package;
 
@@ -450,7 +450,7 @@ class PackageWarningOptions {
 }
 
 class PackageWarningCounter {
-  final Map<Element, Map<PackageWarning, Set<String>>> _countedWarnings = {};
+  final Map<Element?, Map<PackageWarning, Set<String>>> _countedWarnings = {};
   final _items = <Jsonable>[];
   final _displayedWarningCounts = <PackageWarning, int>{};
   final PackageGraph packageGraph;
@@ -467,7 +467,7 @@ class PackageWarningCounter {
 
   /// An unmodifiable map view of all counted warnings related by their element,
   /// warning type, and message.
-  UnmodifiableMapView<Element, Map<PackageWarning, Set<String>>>
+  UnmodifiableMapView<Element?, Map<PackageWarning, Set<String>>>
       get countedWarnings => UnmodifiableMapView(_countedWarnings);
 
   PackageWarningCounter(this.packageGraph);

test/end2end/model_special_cases_test.dart

@@ -311,6 +311,7 @@ void main() {
       expect(injectSimpleHtml.documentationAsHtml,
           contains('   <div style="opacity: 0.5;">[HtmlInjection]</div>'));
     });
+
     test('can inject HTML from tool', () {
       var envLine = RegExp(r'^Env: \{', multiLine: true);
       expect(envLine.allMatches(injectHtmlFromTool.documentation).length,