Issue 190731. Support for aliasElement/aliasArguments in TypeParameterType.

Bug: #45291
Change-Id: Ia0378722f0e7c48e7a3042c0ef14d6833c7bf2b9
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/190734
Reviewed-by: Janice Collins <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/element/element.dart

@@ -7152,6 +7152,13 @@ class TypeAliasElementImpl extends _ExistingElementImpl
         aliasElement: this,
         aliasArguments: typeArguments,
       );
+    } else if (type is TypeParameterType) {
+      return TypeParameterTypeImpl(
+        element: type.element,
+        nullabilitySuffix: resultNullability,
+        aliasElement: this,
+        aliasArguments: typeArguments,
+      );
     } else {
       return (type as TypeImpl).withNullability(resultNullability);
     }

pkg/analyzer/lib/src/dart/element/replacement_visitor.dart

@@ -135,6 +135,8 @@ class ReplacementVisitor
       element: type.element,
       nullabilitySuffix: newNullability ?? type.nullabilitySuffix,
       promotedBound: newPromotedBound ?? promotedBound,
+      aliasElement: type.aliasElement,
+      aliasArguments: type.aliasArguments,
     );
   }
 
@@ -149,6 +151,8 @@ class ReplacementVisitor
     return TypeParameterTypeImpl(
       element: type.element,
       nullabilitySuffix: newNullability,
+      aliasElement: type.aliasElement,
+      aliasArguments: type.aliasArguments,
     );
   }
 

pkg/analyzer/lib/src/dart/element/type.dart

@@ -1801,7 +1801,13 @@ class TypeParameterTypeImpl extends TypeImpl implements TypeParameterType {
     required TypeParameterElement element,
     required this.nullabilitySuffix,
     this.promotedBound,
-  }) : super(element);
+    TypeAliasElement? aliasElement,
+    List<DartType>? aliasArguments,
+  }) : super(
+          element,
+          aliasElement: aliasElement,
+          aliasArguments: aliasArguments,
+        );
 
   @override
   DartType get bound =>

pkg/analyzer/lib/src/dart/element/type_demotion.dart

@@ -38,6 +38,8 @@ class DemotionNonNullificationVisitor extends ReplacementVisitor {
         return TypeParameterTypeImpl(
           element: type.element,
           nullabilitySuffix: newNullability ?? type.nullabilitySuffix,
+          aliasElement: type.aliasElement,
+          aliasArguments: type.aliasArguments,
         );
       }
     }

pkg/analyzer/lib/src/summary2/bundle_reader.dart

@@ -744,6 +744,13 @@ class LinkedResolutionReader {
           aliasElement: aliasElement,
           aliasArguments: aliasArguments,
         );
+      } else if (type is TypeParameterType) {
+        return TypeParameterTypeImpl(
+          element: type.element,
+          nullabilitySuffix: type.nullabilitySuffix,
+          aliasElement: aliasElement,
+          aliasArguments: aliasArguments,
+        );
       } else if (type is VoidType) {
         // TODO(scheglov) add support for `void` aliasing
         return type;

pkg/analyzer/test/src/summary/resynthesize_common.dart

@@ -12509,10 +12509,6 @@ void f2(Never?<aliasElement: self::@typeAlias::A2, aliasArguments: [int]> a) {}
         withAliasElementArguments: true);
   }
 
-  @FailingTest(
-    issue: 'https://github.com/dart-lang/sdk/issues/45291',
-    reason: 'Must be implemented',
-  )
   test_typedef_nonFunction_aliasElement_typeParameterType() async {
     featureSet = FeatureSets.nonFunctionTypeAliases;
     var library = await checkLibrary(r'''