Require analyzer ^8.1.1 and migrate off deprecated APIs (#4086)

Fixes #4085

Author: fshcheglov

CHANGELOG.md

@@ -4,6 +4,8 @@
 * Remove the deprecated `nodoc` option.
 * Remove the deprecated `include-external` option.
 * Refactor 404 error page to use div instead of p for search form.
+* Require analyzer 8.1.1 APIs.
+* Many internal migrations for analyzer APIs.
 
 ## 8.3.4
 * The URL for category pages now uses _category name_ instead of

lib/src/dartdoc_options.dart

@@ -14,7 +14,7 @@ library;
 
 import 'dart:io' show exitCode, stderr, stdout;
 
-import 'package:analyzer/dart/element/element2.dart';
+import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:args/args.dart';
 import 'package:dartdoc/src/dartdoc.dart' show dartdocVersion, programName;
@@ -1128,18 +1128,18 @@ class DartdocOptionContext extends DartdocOptionContextBase
   /// Build a DartdocOptionContext from an analyzer element (using its source
   /// location).
   factory DartdocOptionContext.fromElement(DartdocOptionSet optionSet,
-      LibraryElement2 libraryElement, ResourceProvider resourceProvider) {
+      LibraryElement libraryElement, ResourceProvider resourceProvider) {
     return DartdocOptionContext(
         optionSet,
         resourceProvider.getFile(libraryElement.firstFragment.source.fullName),
         resourceProvider);
   }
 
   /// Build a DartdocOptionContext from an existing [DartdocOptionContext] and a
-  /// new analyzer [Element2].
+  /// new analyzer [Element].
   factory DartdocOptionContext.fromContextElement(
       DartdocOptionContext optionContext,
-      LibraryElement2 libraryElement,
+      LibraryElement libraryElement,
       ResourceProvider resourceProvider) {
     return DartdocOptionContext.fromElement(
         optionContext.optionSet, libraryElement, resourceProvider);

lib/src/element_type.dart

@@ -7,7 +7,7 @@
 /// The only entrypoint for constructing these classes is [ElementType.for_].
 library;
 
-import 'package:analyzer/dart/element/element2.dart';
+import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/nullability_suffix.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:dartdoc/src/model/comment_referable.dart';
@@ -67,7 +67,7 @@ abstract class ElementType with CommentReferable, Nameable {
   String toString() => '$type';
 }
 
-/// An [ElementType] that isn't pinned to an [Element2] (or one that is, but
+/// An [ElementType] that isn't pinned to an [Element] (or one that is, but
 /// whose element is irrelevant).
 class UndefinedElementType extends ElementType {
   UndefinedElementType._(super.type, super.library, super.packageGraph)
@@ -102,9 +102,9 @@ class UndefinedElementType extends ElementType {
     // We can not simply throw here because not all SDK libraries resolve
     // all types.
     if (type is InvalidType) return 'dynamic';
-    assert(const {'Never'}.contains(type.documentableElement2?.name3),
+    assert(const {'Never'}.contains(type.documentableElement2?.name),
         'Unrecognized type for UndefinedElementType: $type');
-    return type.documentableElement2!.name3!;
+    return type.documentableElement2!.name!;
   }
 
   @override
@@ -129,7 +129,7 @@ class UndefinedElementType extends ElementType {
   Iterable<CommentReferable>? get referenceGrandparentOverrides => null;
 }
 
-/// A [FunctionType] that does not have an underpinning [Element2].
+/// A [FunctionType] that does not have an underpinning [Element].
 class FunctionTypeElementType extends UndefinedElementType
     with Rendered, Callable {
   FunctionTypeElementType._(
@@ -205,10 +205,10 @@ class ParameterizedElementType extends DefinedElementType with Rendered {
 
 /// An [ElementType] whose underlying type was referred to by a type alias.
 mixin Aliased implements ElementType {
-  Element2 get typeAliasElement2 => type.alias!.element2;
+  Element get typeAliasElement2 => type.alias!.element;
 
   @override
-  String get name => typeAliasElement2.name3!;
+  String get name => typeAliasElement2.name!;
 
   @override
   bool get isTypedef => true;
@@ -253,7 +253,7 @@ class TypeParameterElementType extends DefinedElementType {
   String get nameWithGenericsPlain => '$name$nullabilitySuffix';
 }
 
-/// An [ElementType] associated with an [Element2].
+/// An [ElementType] associated with an [Element].
 abstract class DefinedElementType extends ElementType {
   final ModelElement modelElement;
 
@@ -263,7 +263,7 @@ abstract class DefinedElementType extends ElementType {
 
   factory DefinedElementType._from(DartType type, ModelElement modelElement,
       Library library, PackageGraph packageGraph) {
-    if (type is! TypeAliasElement2 && type.alias != null) {
+    if (type is! TypeAliasElement && type.alias != null) {
       // Here, `alias.element` signals that this is a type referring to an
       // alias. (`TypeAliasElement.alias.element` has different implications.
       // In that case it is an actual type alias of some kind (generic or
@@ -288,7 +288,7 @@ abstract class DefinedElementType extends ElementType {
   }
 
   @override
-  String get name => type.documentableElement2!.name3!;
+  String get name => type.documentableElement2!.name!;
 
   @override
   String get fullyQualifiedName => modelElement.fullyQualifiedName;