Remove null safety badge (#3295)

Author: parlough

lib/src/element_type.dart

@@ -423,7 +423,7 @@ class GenericTypeAliasElementType extends TypeParameterElementType {
 extension on DartType {
   /// The dartdoc nullability suffix for this type in [library].
   String nullabilitySuffixWithin(Library library) {
-    if (library.isNullSafety && !isVoid && !isBottom) {
+    if (!isVoid && !isBottom) {
       /// If a legacy type appears inside the public interface of a Null
       /// safety library, we pretend it is nullable for the purpose of
       /// documentation (since star-types are not supposed to be public).

lib/src/generator/templates.runtime_renderers.dart

@@ -5261,13 +5261,6 @@ class _Renderer_FeatureSet extends RendererBase<FeatureSet> {
                       self.renderSimpleVariable(c, remainingNames, 'bool'),
                   getBool: (CT_ c) => c.hasFeatureSet == true,
                 ),
-                'isNullSafety': Property(
-                  getValue: (CT_ c) => c.isNullSafety,
-                  renderVariable: (CT_ c, Property<CT_> self,
-                          List<String> remainingNames) =>
-                      self.renderSimpleVariable(c, remainingNames, 'bool'),
-                  getBool: (CT_ c) => c.isNullSafety == true,
-                ),
                 'library': Property(
                   getValue: (CT_ c) => c.library,
                   renderVariable:
@@ -7826,13 +7819,6 @@ class _Renderer_Library extends RendererBase<Library> {
                       self.renderSimpleVariable(c, remainingNames, 'bool'),
                   getBool: (CT_ c) => c.isInSdk == true,
                 ),
-                'isNullSafety': Property(
-                  getValue: (CT_ c) => c.isNullSafety,
-                  renderVariable: (CT_ c, Property<CT_> self,
-                          List<String> remainingNames) =>
-                      self.renderSimpleVariable(c, remainingNames, 'bool'),
-                  getBool: (CT_ c) => c.isNullSafety == true,
-                ),
                 'isPublic': Property(
                   getValue: (CT_ c) => c.isPublic,
                   renderVariable: (CT_ c, Property<CT_> self,

lib/src/model/feature_set.dart

@@ -13,18 +13,7 @@ mixin FeatureSet {
 
   /// A list of language features that both apply to this [ModelElement] and
   /// make sense to display in context.
-  Iterable<LanguageFeature> get displayedLanguageFeatures sync* {
-    // TODO(jcollins-g): Implement mixed-mode handling and the tagging of
-    // legacy interfaces.
-    if (isNullSafety) {
-      yield LanguageFeature(
-          'Null safety', packageGraph.rendererFactory.languageFeatureRenderer);
-    }
-  }
+  Iterable<LanguageFeature> get displayedLanguageFeatures => const [];
 
   bool get hasFeatureSet => displayedLanguageFeatures.isNotEmpty;
-
-  // TODO(jcollins-g): This is an approximation and not strictly true for
-  // inheritance/reexports.
-  bool get isNullSafety => library.isNullSafety;
 }

lib/src/model/language_feature.dart

@@ -4,13 +4,9 @@
 
 import 'package:dartdoc/src/render/language_feature_renderer.dart';
 
-const Map<String, String> _featureDescriptions = {
-  'Null safety': 'Supports the null safety language feature.',
-};
+const Map<String, String> _featureDescriptions = {};
 
-const Map<String, String> _featureUrls = {
-  'Null safety': 'https://dart.dev/null-safety',
-};
+const Map<String, String> _featureUrls = {};
 
 /// An abstraction for a language feature; used to render tags to notify
 /// the user that the documentation should be specially interpreted.

lib/src/model/library.dart

@@ -208,17 +208,6 @@ class Library extends ModelElement with Categorization, TopLevelContainer {
   @override
   Scope get scope => element.scope;
 
-  /// Whether this library is in a package configured to be treated as using
-  /// null safety and itself uses null safety.
-  bool get _allowsNullSafety => element.isNonNullableByDefault;
-
-  /// Whether this library should be documented as using null safety.
-  ///
-  /// A library may use null safety but not be documented that way.
-  @override
-  bool get isNullSafety =>
-      config.enableExperiment.contains('non-nullable') && _allowsNullSafety;
-
   bool get isInSdk => element.isInSdk;
 
   /// [allModelElements] resolved to their original names.

test/end2end/model_test.dart

@@ -314,10 +314,6 @@ void main() {
           equals(''));
     });
 
-    test('isNullSafety is set correctly for libraries', () {
-      expect(lateFinalWithoutInitializer.isNullSafety, isTrue);
-    });
-
     test('method parameters with required', () {
       var m1 = b.instanceMethods.firstWhere((m) => m.name == 'm1');
       var p1 = m1.parameters.firstWhere((p) => p.name == 'p1');
@@ -416,7 +412,6 @@ void main() {
     test('complex nullable elements are detected and rendered correctly', () {
       var complexNullableMembers = nullableElements.allClasses
           .firstWhere((c) => c.name == 'ComplexNullableMembers');
-      expect(complexNullableMembers.isNullSafety, isTrue);
       expect(
           complexNullableMembers.nameWithGenerics,
           equals(
@@ -430,7 +425,6 @@ void main() {
           .firstWhere((f) => f.name == 'methodWithNullables');
       var operatorStar = nullableMembers.publicInstanceOperators
           .firstWhere((f) => f.name == 'operator *');
-      expect(nullableMembers.isNullSafety, isTrue);
       expect(
           methodWithNullables.linkedParams,
           equals(