diff --git a/pkg/compiler/lib/src/ir/visitors.dart b/pkg/compiler/lib/src/ir/visitors.dart
index 8557c88e7dc..f07422e9329 100644
--- a/pkg/compiler/lib/src/ir/visitors.dart
+++ b/pkg/compiler/lib/src/ir/visitors.dart
@@ -218,6 +218,11 @@ class DartTypeConverter extends ir.DartTypeVisitor<DartType> {
   DartType defaultDartType(ir.DartType node) {
     throw UnsupportedError('Unsupported type $node (${node.runtimeType})');
   }
+
+  @override
+  DartType visitTypedefType(ir.TypedefType node) {
+    throw UnsupportedError('Unsupported type $node (${node.runtimeType})');
+  }
 }
 
 class ConstantValuefier extends ir.ComputeOnceConstantVisitor<ConstantValue> {
diff --git a/pkg/dev_compiler/lib/src/kernel/type_recipe_generator.dart b/pkg/dev_compiler/lib/src/kernel/type_recipe_generator.dart
index d4055a8c0fd..8b34fce83f0 100644
--- a/pkg/dev_compiler/lib/src/kernel/type_recipe_generator.dart
+++ b/pkg/dev_compiler/lib/src/kernel/type_recipe_generator.dart
@@ -255,6 +255,10 @@ class _TypeRecipeVisitor extends DartTypeVisitor<String> {
   String defaultDartType(DartType node) =>
       throw UnimplementedError('Unknown DartType: $node');
 
+  @override
+  String visitInvalidType(DartType node) =>
+      throw UnimplementedError('Unknown DartType: $node');
+
   @override
   String visitDynamicType(DynamicType node) => Recipe.pushDynamicString;
 
diff --git a/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart b/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
index 5323341999d..d7a415e5953 100644
--- a/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/constant_evaluator.dart
@@ -24,6 +24,7 @@ import 'package:kernel/ast.dart';
 import 'package:kernel/class_hierarchy.dart';
 import 'package:kernel/core_types.dart';
 import 'package:kernel/src/const_canonical_type.dart';
+import 'package:kernel/src/find_type_visitor.dart';
 import 'package:kernel/src/legacy_erasure.dart';
 import 'package:kernel/src/norm.dart';
 import 'package:kernel/src/printer.dart'
@@ -6215,88 +6216,25 @@ class SimpleErrorReporter implements ErrorReporter {
 }
 
 bool isInstantiated(DartType type) {
-  return type.accept(new IsInstantiatedVisitor());
+  return !type.accept(new HasUninstantiatedVisitor());
 }
 
-class IsInstantiatedVisitor implements DartTypeVisitor<bool> {
+class HasUninstantiatedVisitor extends FindTypeVisitor {
   final _availableVariables = new Set<TypeParameter>();
 
-  bool isInstantiated(DartType type) {
-    return type.accept(this);
-  }
-
-  @override
-  bool defaultDartType(DartType node) {
-    // Probably unreachable.
-    throw 'A visitor method seems to be unimplemented!';
-  }
-
-  @override
-  bool visitInvalidType(InvalidType node) => true;
-
-  @override
-  bool visitDynamicType(DynamicType node) => true;
-
-  @override
-  bool visitVoidType(VoidType node) => true;
-
-  @override
-  bool visitNullType(NullType node) => true;
-
   @override
   bool visitTypeParameterType(TypeParameterType node) {
-    return _availableVariables.contains(node.parameter);
-  }
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    return node.typeArguments
-        .every((DartType typeArgument) => typeArgument.accept(this));
-  }
-
-  @override
-  bool visitFutureOrType(FutureOrType node) {
-    return node.typeArgument.accept(this);
+    return !_availableVariables.contains(node.parameter);
   }
 
   @override
   bool visitFunctionType(FunctionType node) {
     final List<TypeParameter> parameters = node.typeParameters;
     _availableVariables.addAll(parameters);
-    final bool result = node.typeParameters
-            .every((p) => p.bound.accept(this) && p.defaultType.accept(this)) &&
-        node.returnType.accept(this) &&
-        node.positionalParameters.every((p) => p.accept(this)) &&
-        node.namedParameters.every((p) => p.type.accept(this));
+    bool result = super.visitFunctionType(node);
     _availableVariables.removeAll(parameters);
     return result;
   }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    // Probably unreachable.
-    return node.unalias.accept(this);
-  }
-
-  @override
-  bool visitNeverType(NeverType node) => true;
-
-  @override
-  bool visitRecordType(RecordType node) {
-    return node.positional.every((p) => p.accept(this)) &&
-        node.named.every((p) => p.type.accept(this));
-  }
-
-  @override
-  bool visitExtensionType(ExtensionType node) {
-    return node.typeArguments
-        .every((DartType typeArgument) => typeArgument.accept(this));
-  }
-
-  @override
-  bool visitIntersectionType(IntersectionType node) {
-    return node.left.accept(this) && node.right.accept(this);
-  }
 }
 
 bool _isFormalParameter(VariableDeclaration variable) {
diff --git a/pkg/front_end/lib/src/fasta/kernel/type_algorithms.dart b/pkg/front_end/lib/src/fasta/kernel/type_algorithms.dart
index 7424604ccbb..966244be20c 100644
--- a/pkg/front_end/lib/src/fasta/kernel/type_algorithms.dart
+++ b/pkg/front_end/lib/src/fasta/kernel/type_algorithms.dart
@@ -4,6 +4,8 @@
 
 import 'package:kernel/ast.dart';
 
+import 'package:kernel/src/find_type_visitor.dart';
+
 import 'package:kernel/type_algebra.dart' show containsTypeVariable;
 
 import 'package:kernel/util/graph.dart' show Graph, computeStrongComponents;
@@ -1334,86 +1336,11 @@ bool hasAnyTypeVariables(DartType type) {
 /// Don't use this directly, use [hasAnyTypeVariables] instead. But don't use
 /// that either.
 // TODO(ahe): Remove this class.
-class TypeVariableSearch implements DartTypeVisitor<bool> {
+class TypeVariableSearch extends FindTypeVisitor {
   const TypeVariableSearch();
 
-  @override
-  bool defaultDartType(DartType node) => throw "unsupported";
-
-  bool anyTypeVariables(List<DartType> types) {
-    for (DartType type in types) {
-      if (type.accept(this)) return true;
-    }
-    return false;
-  }
-
-  @override
-  bool visitInvalidType(InvalidType node) => false;
-
-  @override
-  bool visitDynamicType(DynamicType node) => false;
-
-  @override
-  bool visitVoidType(VoidType node) => false;
-
-  @override
-  bool visitNeverType(NeverType node) => false;
-
-  @override
-  bool visitNullType(NullType node) => false;
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    return anyTypeVariables(node.typeArguments);
-  }
-
-  @override
-  bool visitExtensionType(ExtensionType node) {
-    return anyTypeVariables(node.typeArguments);
-  }
-
-  @override
-  bool visitFutureOrType(FutureOrType node) {
-    return node.typeArgument.accept(this);
-  }
-
-  @override
-  bool visitFunctionType(FunctionType node) {
-    if (anyTypeVariables(node.positionalParameters)) return true;
-    for (TypeParameter variable in node.typeParameters) {
-      if (variable.bound.accept(this)) return true;
-    }
-    for (NamedType type in node.namedParameters) {
-      if (type.type.accept(this)) return true;
-    }
-    return false;
-  }
-
   @override
   bool visitTypeParameterType(TypeParameterType node) => true;
-
-  @override
-  bool visitIntersectionType(IntersectionType node) {
-    // The left-hand side of an [IntersectionType] is always a
-    // [TypeParameterType].
-    // ignore: unnecessary_type_check
-    assert(node.left is TypeParameterType);
-    return true;
-  }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    return anyTypeVariables(node.typeArguments);
-  }
-
-  @override
-  bool visitRecordType(RecordType node) {
-    if (anyTypeVariables(node.positional)) return true;
-    for (NamedType namedType in node.named) {
-      if (namedType.type.accept(this)) return true;
-    }
-    return false;
-  }
 }
 
 /// A representation of a found non-simplicity issue in bounds
diff --git a/pkg/front_end/lib/src/fasta/type_inference/inference_results.dart b/pkg/front_end/lib/src/fasta/type_inference/inference_results.dart
index 3552ae1ad9c..932a9b8f5b8 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/inference_results.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/inference_results.dart
@@ -343,7 +343,7 @@ class ExpressionInferenceResult {
 
   ExpressionInferenceResult(this.inferredType, this.expression,
       {this.postCoercionType = null})
-      : assert(isKnown(inferredType));
+      : assert(isKnown(inferredType), "$inferredType is not known.");
 
   /// The guards used for null-aware access if the expression is part of a
   /// null-shorting.
diff --git a/pkg/front_end/lib/src/fasta/type_inference/inference_visitor_base.dart b/pkg/front_end/lib/src/fasta/type_inference/inference_visitor_base.dart
index 298a707f8ac..5292e033d5e 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/inference_visitor_base.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/inference_visitor_base.dart
@@ -739,6 +739,7 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       DartType contextType, Template<Message Function(String)> template) {
     Expression errorNode = new AsExpression(
         expression,
+        // TODO(johnniwinther): Fix this.
         // TODO(ahe): The outline phase doesn't correctly remove invalid
         // uses of type variables, for example, on static members. Once
         // that has been fixed, we should always be able to use
@@ -763,6 +764,7 @@ abstract class InferenceVisitorBase implements InferenceVisitor {
       {List<LocatedMessage>? context}) {
     Expression errorNode = new AsExpression(
         expression,
+        // TODO(johnniwinther): Fix this.
         // TODO(ahe): The outline phase doesn't correctly remove invalid
         // uses of type variables, for example, on static members. Once
         // that has been fixed, we should always be able to use
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_demotion.dart b/pkg/front_end/lib/src/fasta/type_inference/type_demotion.dart
index e2e0472ead7..dc66e0905c2 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_demotion.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_demotion.dart
@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE.md file.
 
 import 'package:kernel/ast.dart';
+import 'package:kernel/src/find_type_visitor.dart';
 import 'package:kernel/src/replacement_visitor.dart';
 
 /// Returns `true` if type contains a promoted type variable.
@@ -11,43 +12,9 @@ bool hasPromotedTypeVariable(DartType type) {
 }
 
 /// Visitor that returns `true` if a type contains a promoted type variable.
-class _HasPromotedTypeVariableVisitor extends DartTypeVisitor<bool> {
+class _HasPromotedTypeVariableVisitor extends FindTypeVisitor {
   const _HasPromotedTypeVariableVisitor();
 
-  @override
-  bool defaultDartType(DartType node) => false;
-
-  @override
-  bool visitFunctionType(FunctionType node) {
-    if (node.returnType.accept(this)) return true;
-    for (DartType parameterType in node.positionalParameters) {
-      if (parameterType.accept(this)) return true;
-    }
-    for (NamedType namedParameterType in node.namedParameters) {
-      if (namedParameterType.type.accept(this)) return true;
-    }
-    return false;
-  }
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    for (DartType typeArgument in node.typeArguments) {
-      if (typeArgument.accept(this)) return true;
-    }
-    return false;
-  }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    for (DartType typeArgument in node.typeArguments) {
-      if (typeArgument.accept(this)) return true;
-    }
-    return false;
-  }
-
-  @override
-  bool visitTypeParameterType(TypeParameterType node) => false;
-
   @override
   bool visitIntersectionType(IntersectionType node) => true;
 }
diff --git a/pkg/front_end/lib/src/fasta/type_inference/type_schema.dart b/pkg/front_end/lib/src/fasta/type_inference/type_schema.dart
index 22f3acbb6fc..a61e9890e78 100644
--- a/pkg/front_end/lib/src/fasta/type_inference/type_schema.dart
+++ b/pkg/front_end/lib/src/fasta/type_inference/type_schema.dart
@@ -4,6 +4,7 @@
 
 import 'package:kernel/ast.dart';
 import 'package:kernel/src/assumptions.dart';
+import 'package:kernel/src/find_type_visitor.dart';
 import 'package:kernel/src/printer.dart';
 
 import 'package:kernel/import_table.dart' show ImportTable;
@@ -12,7 +13,7 @@ import 'package:kernel/text/ast_to_text.dart'
     show Annotator, NameSystem, Printer, globalDebuggingNames;
 
 /// Determines whether a type schema contains `?` somewhere inside it.
-bool isKnown(DartType schema) => schema.accept(const _IsKnownVisitor());
+bool isKnown(DartType schema) => !schema.accept(const _HasUnknownVisitor());
 
 /// Converts a [DartType] to a string, representing the unknown type as `?`.
 String typeSchemaToString(DartType schema) {
@@ -95,87 +96,10 @@ class UnknownType extends DartType {
   }
 }
 
-/// Visitor that computes [isKnown].
-class _IsKnownVisitor implements DartTypeVisitor<bool> {
-  const _IsKnownVisitor();
+/// Visitor used to compute [isKnown].
+class _HasUnknownVisitor extends FindTypeVisitor {
+  const _HasUnknownVisitor();
 
   @override
-  bool defaultDartType(DartType node) => node is! UnknownType;
-
-  @override
-  bool visitDynamicType(DynamicType node) => true;
-
-  @override
-  bool visitInvalidType(InvalidType node) => true;
-
-  @override
-  bool visitNeverType(NeverType node) => true;
-
-  @override
-  bool visitIntersectionType(IntersectionType node) => true;
-
-  @override
-  bool visitNullType(NullType node) => true;
-
-  @override
-  bool visitTypeParameterType(TypeParameterType node) => true;
-
-  @override
-  bool visitVoidType(VoidType node) => true;
-
-  @override
-  bool visitFunctionType(FunctionType node) {
-    if (!node.returnType.accept(this)) return false;
-    for (DartType parameterType in node.positionalParameters) {
-      if (!parameterType.accept(this)) return false;
-    }
-    for (NamedType namedParameterType in node.namedParameters) {
-      if (!namedParameterType.type.accept(this)) return false;
-    }
-    for (TypeParameter typeParameter in node.typeParameters) {
-      if (!typeParameter.bound.accept(this)) return false;
-      if (!typeParameter.defaultType.accept(this)) return false;
-    }
-    return true;
-  }
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    for (DartType typeArgument in node.typeArguments) {
-      if (!typeArgument.accept(this)) return false;
-    }
-    return true;
-  }
-
-  @override
-  bool visitExtensionType(ExtensionType node) {
-    for (DartType typeArgument in node.typeArguments) {
-      if (!typeArgument.accept(this)) return false;
-    }
-    return true;
-  }
-
-  @override
-  bool visitRecordType(RecordType node) {
-    for (DartType positional in node.positional) {
-      if (!positional.accept(this)) return false;
-    }
-    for (NamedType named in node.named) {
-      if (!named.type.accept(this)) return false;
-    }
-    return true;
-  }
-
-  @override
-  bool visitFutureOrType(FutureOrType node) {
-    return node.typeArgument.accept(this);
-  }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    for (DartType typeArgument in node.typeArguments) {
-      if (!typeArgument.accept(this)) return false;
-    }
-    return true;
-  }
+  bool defaultDartType(DartType node) => node is UnknownType;
 }
diff --git a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.expect b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.expect
index 27c84840f72..7ad3c232843 100644
--- a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.expect
+++ b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.expect
@@ -100,7 +100,7 @@ B<Y> Function<Y>() test17() => DB2.new; // Error.
                                ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:42:32: Error: A value of type 'B<X> Function<X extends num>()' can't be assigned to a variable of type 'B<Y> Function<Y>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y>() test17() => DB2.new; // Error.
-                               ^" in #C12 as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%> as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%>;
+                               ^" in #C12 as{TypeError} Never as{TypeError} Never;
 static method test18() → () → self::B<core::num>
   return #C9;
 static method test19() → () → self::B<core::num>
@@ -118,7 +118,7 @@ B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
                                   ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:49:35: Error: A value of type 'B<X> Function<X extends num, Y extends String>()' can't be assigned to a variable of type 'B<Y> Function<Y, Z>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
-                                  ^" in #C13 as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%> as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%>;
+                                  ^" in #C13 as{TypeError} Never as{TypeError} Never;
 static method test24() → () → self::B<core::String>
   return #C14;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.transformed.expect b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.transformed.expect
index 82e359a0235..90ee3101a70 100644
--- a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.strong.transformed.expect
@@ -100,7 +100,7 @@ B<Y> Function<Y>() test17() => DB2.new; // Error.
                                ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:42:32: Error: A value of type 'B<X> Function<X extends num>()' can't be assigned to a variable of type 'B<Y> Function<Y>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y>() test17() => DB2.new; // Error.
-                               ^" in #C12 as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%>;
+                               ^" in #C12 as{TypeError} Never;
 static method test18() → () → self::B<core::num>
   return #C9;
 static method test19() → () → self::B<core::num>
@@ -118,7 +118,7 @@ B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
                                   ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:49:35: Error: A value of type 'B<X> Function<X extends num, Y extends String>()' can't be assigned to a variable of type 'B<Y> Function<Y, Z>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
-                                  ^" in #C13 as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%>;
+                                  ^" in #C13 as{TypeError} Never;
 static method test24() → () → self::B<core::String>
   return #C14;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.expect b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.expect
index 8cfb1b4a6dc..8424da86f29 100644
--- a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.expect
+++ b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.expect
@@ -100,7 +100,7 @@ B<Y> Function<Y>() test17() => DB2.new; // Error.
                                ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:42:32: Error: A value of type 'B<X> Function<X extends num>()' can't be assigned to a variable of type 'B<Y> Function<Y>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y>() test17() => DB2.new; // Error.
-                               ^" in #C12 as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%> as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%>;
+                               ^" in #C12 as{TypeError} Never as{TypeError} Never;
 static method test18() → () → self::B<core::num>
   return #C9;
 static method test19() → () → self::B<core::num>
@@ -118,7 +118,7 @@ B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
                                   ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:49:35: Error: A value of type 'B<X> Function<X extends num, Y extends String>()' can't be assigned to a variable of type 'B<Y> Function<Y, Z>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
-                                  ^" in #C13 as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%> as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%>;
+                                  ^" in #C13 as{TypeError} Never as{TypeError} Never;
 static method test24() → () → self::B<core::String>
   return #C14;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.modular.expect b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.modular.expect
index 8cfb1b4a6dc..8424da86f29 100644
--- a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.modular.expect
@@ -100,7 +100,7 @@ B<Y> Function<Y>() test17() => DB2.new; // Error.
                                ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:42:32: Error: A value of type 'B<X> Function<X extends num>()' can't be assigned to a variable of type 'B<Y> Function<Y>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y>() test17() => DB2.new; // Error.
-                               ^" in #C12 as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%> as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%>;
+                               ^" in #C12 as{TypeError} Never as{TypeError} Never;
 static method test18() → () → self::B<core::num>
   return #C9;
 static method test19() → () → self::B<core::num>
@@ -118,7 +118,7 @@ B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
                                   ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:49:35: Error: A value of type 'B<X> Function<X extends num, Y extends String>()' can't be assigned to a variable of type 'B<Y> Function<Y, Z>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
-                                  ^" in #C13 as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%> as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%>;
+                                  ^" in #C13 as{TypeError} Never as{TypeError} Never;
 static method test24() → () → self::B<core::String>
   return #C14;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.transformed.expect b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.transformed.expect
index f2f30c32e31..61125f38276 100644
--- a/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart.weak.transformed.expect
@@ -100,7 +100,7 @@ B<Y> Function<Y>() test17() => DB2.new; // Error.
                                ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:42:32: Error: A value of type 'B<X> Function<X extends num>()' can't be assigned to a variable of type 'B<Y> Function<Y>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y>() test17() => DB2.new; // Error.
-                               ^" in #C12 as{TypeError} <Y extends core::Object? = dynamic>() → self::B<Y%>;
+                               ^" in #C12 as{TypeError} Never;
 static method test18() → () → self::B<core::num>
   return #C9;
 static method test19() → () → self::B<core::num>
@@ -118,7 +118,7 @@ B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
                                   ^" in invalid-expression "pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart:49:35: Error: A value of type 'B<X> Function<X extends num, Y extends String>()' can't be assigned to a variable of type 'B<Y> Function<Y, Z>()'.
  - 'B' is from 'pkg/front_end/testcases/constructor_tearoffs/typedef_tearoffs.dart'.
 B<Y> Function<Y, Z>() test23() => DB3.new; // Error.
-                                  ^" in #C13 as{TypeError} <Y extends core::Object? = dynamic, Z extends core::Object? = dynamic>() → self::B<Y%>;
+                                  ^" in #C13 as{TypeError} Never;
 static method test24() → () → self::B<core::String>
   return #C14;
 static method main() → dynamic {}
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart
index 162d4679f51..39daf670a3e 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart
@@ -23,14 +23,14 @@ test(
   List<T4> t4b, // Error,
   void Function(T4) t4c, // Error
   void Function(List<T4>) t4d, // Error
-  T5 t5a, // Error,
-  List<T5> t5b, // Error,
-  void Function(T5) t5c, // Error
-  void Function(List<T5>) t5d, // Error
-  T6 t6a, // Error,
-  List<T6> t6b, // Error,
-  void Function(T6) t6c, // Error
-  void Function(List<T6>) t6d, // Error
+  T5 t5a, // Ok,
+  List<T5> t5b, // Ok,
+  void Function(T5) t5c, // Ok
+  void Function(List<T5>) t5d, // Ok
+  T6 t6a, // Ok,
+  List<T6> t6b, // Ok,
+  void Function(T6) t6c, // Ok
+  void Function(List<T6>) t6d, // Ok
   T7 t7a, // Error,
   List<T7> t7b, // Error,
   void Function(T7) t7c, // Error
@@ -39,6 +39,22 @@ test(
   List<T8> t8b, // Error,
   void Function(T8) t8c, // Error
   void Function(List<T8>) t8d, // Error
+  T9 t9a, // Error,
+  List<T9> t9b, // Error,
+  void Function(T9) t9c, // Error
+  void Function(List<T9>) t9d, // Error
+  T10 t10a, // Error,
+  List<T10> t10b, // Error,
+  void Function(T10) t10c, // Error
+  void Function(List<T10>) t10d, // Error
+  T11 t11a, // Ok,
+  List<T11> t11b, // Ok,
+  void Function(T11) t11c, // Ok
+  void Function(List<T11>) t11d, // Ok
+  T12 t12a, // Error,
+  List<T12> t12b, // Error,
+  void Function(T12) t12c, // Error
+  void Function(List<T12>) t12d, // Error
 ) {
   new T4(); // Error
   <T4>[]; // Error
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.expect
index 1fcd376edc7..3e68c6d5abb 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.expect
@@ -66,43 +66,150 @@ library;
 //   void Function(List<T3>) t3d, // Error
 //                      ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:34:3: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   T7 t7a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:35:8: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   List<T7> t7b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:36:17: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T7) t7c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:37:22: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T7>) t7d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:42:3: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T9 t9a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:8: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T9> t9b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:17: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T9) t9c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:22: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T9>) t9d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:3: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T10 t10a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:8: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T10> t10b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:48:17: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T10) t10c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:49:22: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T10>) t10d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:54:3: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T12 t12a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:55:8: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T12> t12b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:56:17: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T12) t12c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:57:22: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T12>) t12d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
 //  - 'List' is from 'dart:core'.
 //   new T7(0); // Error
 //          ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:59:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   new T4(); // Error
 //       ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:60:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <T4>[]; // Error
 //    ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:61:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(T4)>[]; // Error
 //                  ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:62:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(List<T4>)>[]; // Error
 //                       ^
 //
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:64:4: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <T7>[]; // Error
+//    ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:65:18: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(T7)>[]; // Error
+//                  ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:66:23: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(List<T7>)>[]; // Error
+//                       ^
+//
 import self as self;
 import "dart:core" as core;
 import "alias_from_opt_in_lib.dart" as ali;
 
 import "org-dartlang-testcase:///alias_from_opt_in_lib.dart";
 
-static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9a, core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)> t9b, ((core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)) → void t9c, (core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)>) → void t9d, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10a, core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})> t10b, (({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})) → void t10c, (core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})>) → void t10d, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11a, core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>> t11b, (FutureOr<<T extends core::Object? = dynamic>(T%) → void>) → void t11c, (core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>>) → void t11d, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12a, core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>> t12b, (FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t12c, (core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>>) → void t12d) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   <ali::Class<<T extends core::Object? = dynamic>(T%) → void>>[];
   <(ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void>[];
   <(core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void>[];
-  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
  - 'List' is from 'dart:core'.
   new T7(0); // Error
          ^" in 0 as{TypeError} core::List<dynamic>);
@@ -116,6 +223,8 @@ library;
 import self as ali;
 import "dart:core" as core;
 
+import "dart:async";
+
 typedef T1 = <T extends core::Object? = dynamic>(T%) → void;
 typedef T2 = (<T extends core::Object? = dynamic>(T%) → void) → void;
 typedef T3 = core::List<<T extends core::Object? = dynamic>(T%) → void>;
@@ -124,6 +233,10 @@ typedef T5 = (<T extends core::Object? = dynamic>(T%) → void, core::int);
 typedef T6 = ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int});
 typedef T7 = ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */;
 typedef T8 = <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void;
+typedef T9 = (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int);
+typedef T10 = ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int});
+typedef T11 = FutureOr<<T extends core::Object? = dynamic>(T%) → void>;
+typedef T12 = FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>;
 class Class<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → ali::Class<ali::Class::T%>
     : super core::Object::•()
@@ -139,7 +252,7 @@ static inline-class-member method ExtensionType|<T extends core::Object? = dynam
 }
 static inline-class-member method ExtensionType|_#new#tearOff<T extends core::Object? = dynamic>(core::List<ali::ExtensionType|_#new#tearOff::T%> it) → ali::ExtensionType<ali::ExtensionType|_#new#tearOff::T%> /* = core::List<ali::ExtensionType|_#new#tearOff::T%> */
   return ali::ExtensionType|<ali::ExtensionType|_#new#tearOff::T%>(it);
-static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   ali::ExtensionType|<dynamic>(<dynamic>[]);
 }
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.transformed.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.transformed.expect
index 089d8b0924d..d529ee36ff2 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.strong.transformed.expect
@@ -66,43 +66,150 @@ library;
 //   void Function(List<T3>) t3d, // Error
 //                      ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:34:3: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   T7 t7a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:35:8: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   List<T7> t7b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:36:17: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T7) t7c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:37:22: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T7>) t7d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:42:3: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T9 t9a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:8: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T9> t9b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:17: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T9) t9c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:22: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T9>) t9d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:3: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T10 t10a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:8: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T10> t10b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:48:17: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T10) t10c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:49:22: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T10>) t10d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:54:3: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T12 t12a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:55:8: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T12> t12b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:56:17: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T12) t12c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:57:22: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T12>) t12d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
 //  - 'List' is from 'dart:core'.
 //   new T7(0); // Error
 //          ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:59:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   new T4(); // Error
 //       ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:60:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <T4>[]; // Error
 //    ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:61:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(T4)>[]; // Error
 //                  ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:62:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(List<T4>)>[]; // Error
 //                       ^
 //
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:64:4: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <T7>[]; // Error
+//    ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:65:18: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(T7)>[]; // Error
+//                  ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:66:23: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(List<T7>)>[]; // Error
+//                       ^
+//
 import self as self;
 import "dart:core" as core;
 import "alias_from_opt_in_lib.dart" as ali;
 
 import "org-dartlang-testcase:///alias_from_opt_in_lib.dart";
 
-static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9a, core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)> t9b, ((core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)) → void t9c, (core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)>) → void t9d, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10a, core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})> t10b, (({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})) → void t10c, (core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})>) → void t10d, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11a, core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>> t11b, (FutureOr<<T extends core::Object? = dynamic>(T%) → void>) → void t11c, (core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>>) → void t11d, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12a, core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>> t12b, (FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t12c, (core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>>) → void t12d) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   core::_GrowableList::•<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>(0);
   core::_GrowableList::•<(ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void>(0);
   core::_GrowableList::•<(core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void>(0);
-  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
  - 'List' is from 'dart:core'.
   new T7(0); // Error
          ^" in 0 as{TypeError} core::List<dynamic>);
@@ -116,6 +223,8 @@ library;
 import self as ali;
 import "dart:core" as core;
 
+import "dart:async";
+
 typedef T1 = <T extends core::Object? = dynamic>(T%) → void;
 typedef T2 = (<T extends core::Object? = dynamic>(T%) → void) → void;
 typedef T3 = core::List<<T extends core::Object? = dynamic>(T%) → void>;
@@ -124,6 +233,10 @@ typedef T5 = (<T extends core::Object? = dynamic>(T%) → void, core::int);
 typedef T6 = ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int});
 typedef T7 = ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */;
 typedef T8 = <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void;
+typedef T9 = (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int);
+typedef T10 = ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int});
+typedef T11 = FutureOr<<T extends core::Object? = dynamic>(T%) → void>;
+typedef T12 = FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>;
 class Class<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → ali::Class<ali::Class::T%>
     : super core::Object::•()
@@ -139,7 +252,7 @@ static inline-class-member method ExtensionType|<T extends core::Object? = dynam
 }
 static inline-class-member method ExtensionType|_#new#tearOff<T extends core::Object? = dynamic>(core::List<ali::ExtensionType|_#new#tearOff::T%> it) → ali::ExtensionType<ali::ExtensionType|_#new#tearOff::T%> /* = core::List<ali::ExtensionType|_#new#tearOff::T%> */
   return ali::ExtensionType|<ali::ExtensionType|_#new#tearOff::T%>(it);
-static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   ali::ExtensionType|<dynamic>(core::_GrowableList::•<dynamic>(0));
 }
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline.expect
index 5ee3b7b0a05..32147d1ddee 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline.expect
@@ -34,5 +34,21 @@ test(
   List<T8> t8b,
   void Function(T8) t8c,
   void Function(List<T8>) t8d,
+  T9 t9a,
+  List<T9> t9b,
+  void Function(T9) t9c,
+  void Function(List<T9>) t9d,
+  T10 t10a,
+  List<T10> t10b,
+  void Function(T10) t10c,
+  void Function(List<T10>) t10d,
+  T11 t11a,
+  List<T11> t11b,
+  void Function(T11) t11c,
+  void Function(List<T11>) t11d,
+  T12 t12a,
+  List<T12> t12b,
+  void Function(T12) t12c,
+  void Function(List<T12>) t12d,
 ) {}
 main() {}
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline_modelled.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline_modelled.expect
index b9f7796c9f6..223377b10b2 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline_modelled.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.textual_outline_modelled.expect
@@ -35,4 +35,20 @@ test(
   List<T8> t8b,
   void Function(T8) t8c,
   void Function(List<T8>) t8d,
+  T9 t9a,
+  List<T9> t9b,
+  void Function(T9) t9c,
+  void Function(List<T9>) t9d,
+  T10 t10a,
+  List<T10> t10b,
+  void Function(T10) t10c,
+  void Function(List<T10>) t10d,
+  T11 t11a,
+  List<T11> t11b,
+  void Function(T11) t11c,
+  void Function(List<T11>) t11d,
+  T12 t12a,
+  List<T12> t12b,
+  void Function(T12) t12c,
+  void Function(List<T12>) t12d,
 ) {}
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.expect
index 1fcd376edc7..3e68c6d5abb 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.expect
@@ -66,43 +66,150 @@ library;
 //   void Function(List<T3>) t3d, // Error
 //                      ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:34:3: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   T7 t7a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:35:8: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   List<T7> t7b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:36:17: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T7) t7c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:37:22: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T7>) t7d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:42:3: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T9 t9a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:8: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T9> t9b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:17: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T9) t9c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:22: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T9>) t9d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:3: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T10 t10a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:8: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T10> t10b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:48:17: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T10) t10c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:49:22: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T10>) t10d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:54:3: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T12 t12a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:55:8: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T12> t12b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:56:17: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T12) t12c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:57:22: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T12>) t12d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
 //  - 'List' is from 'dart:core'.
 //   new T7(0); // Error
 //          ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:59:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   new T4(); // Error
 //       ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:60:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <T4>[]; // Error
 //    ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:61:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(T4)>[]; // Error
 //                  ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:62:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(List<T4>)>[]; // Error
 //                       ^
 //
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:64:4: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <T7>[]; // Error
+//    ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:65:18: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(T7)>[]; // Error
+//                  ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:66:23: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(List<T7>)>[]; // Error
+//                       ^
+//
 import self as self;
 import "dart:core" as core;
 import "alias_from_opt_in_lib.dart" as ali;
 
 import "org-dartlang-testcase:///alias_from_opt_in_lib.dart";
 
-static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9a, core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)> t9b, ((core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)) → void t9c, (core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)>) → void t9d, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10a, core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})> t10b, (({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})) → void t10c, (core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})>) → void t10d, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11a, core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>> t11b, (FutureOr<<T extends core::Object? = dynamic>(T%) → void>) → void t11c, (core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>>) → void t11d, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12a, core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>> t12b, (FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t12c, (core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>>) → void t12d) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   <ali::Class<<T extends core::Object? = dynamic>(T%) → void>>[];
   <(ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void>[];
   <(core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void>[];
-  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
  - 'List' is from 'dart:core'.
   new T7(0); // Error
          ^" in 0 as{TypeError} core::List<dynamic>);
@@ -116,6 +223,8 @@ library;
 import self as ali;
 import "dart:core" as core;
 
+import "dart:async";
+
 typedef T1 = <T extends core::Object? = dynamic>(T%) → void;
 typedef T2 = (<T extends core::Object? = dynamic>(T%) → void) → void;
 typedef T3 = core::List<<T extends core::Object? = dynamic>(T%) → void>;
@@ -124,6 +233,10 @@ typedef T5 = (<T extends core::Object? = dynamic>(T%) → void, core::int);
 typedef T6 = ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int});
 typedef T7 = ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */;
 typedef T8 = <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void;
+typedef T9 = (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int);
+typedef T10 = ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int});
+typedef T11 = FutureOr<<T extends core::Object? = dynamic>(T%) → void>;
+typedef T12 = FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>;
 class Class<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → ali::Class<ali::Class::T%>
     : super core::Object::•()
@@ -139,7 +252,7 @@ static inline-class-member method ExtensionType|<T extends core::Object? = dynam
 }
 static inline-class-member method ExtensionType|_#new#tearOff<T extends core::Object? = dynamic>(core::List<ali::ExtensionType|_#new#tearOff::T%> it) → ali::ExtensionType<ali::ExtensionType|_#new#tearOff::T%> /* = core::List<ali::ExtensionType|_#new#tearOff::T%> */
   return ali::ExtensionType|<ali::ExtensionType|_#new#tearOff::T%>(it);
-static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   ali::ExtensionType|<dynamic>(<dynamic>[]);
 }
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.modular.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.modular.expect
index 1fcd376edc7..3e68c6d5abb 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.modular.expect
@@ -66,43 +66,150 @@ library;
 //   void Function(List<T3>) t3d, // Error
 //                      ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:34:3: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   T7 t7a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:35:8: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   List<T7> t7b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:36:17: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T7) t7c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:37:22: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T7>) t7d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:42:3: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T9 t9a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:8: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T9> t9b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:17: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T9) t9c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:22: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T9>) t9d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:3: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T10 t10a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:8: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T10> t10b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:48:17: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T10) t10c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:49:22: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T10>) t10d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:54:3: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T12 t12a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:55:8: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T12> t12b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:56:17: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T12) t12c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:57:22: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T12>) t12d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
 //  - 'List' is from 'dart:core'.
 //   new T7(0); // Error
 //          ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:59:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   new T4(); // Error
 //       ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:60:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <T4>[]; // Error
 //    ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:61:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(T4)>[]; // Error
 //                  ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:62:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(List<T4>)>[]; // Error
 //                       ^
 //
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:64:4: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <T7>[]; // Error
+//    ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:65:18: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(T7)>[]; // Error
+//                  ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:66:23: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(List<T7>)>[]; // Error
+//                       ^
+//
 import self as self;
 import "dart:core" as core;
 import "alias_from_opt_in_lib.dart" as ali;
 
 import "org-dartlang-testcase:///alias_from_opt_in_lib.dart";
 
-static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9a, core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)> t9b, ((core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)) → void t9c, (core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)>) → void t9d, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10a, core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})> t10b, (({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})) → void t10c, (core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})>) → void t10d, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11a, core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>> t11b, (FutureOr<<T extends core::Object? = dynamic>(T%) → void>) → void t11c, (core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>>) → void t11d, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12a, core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>> t12b, (FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t12c, (core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>>) → void t12d) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   <ali::Class<<T extends core::Object? = dynamic>(T%) → void>>[];
   <(ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void>[];
   <(core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void>[];
-  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
  - 'List' is from 'dart:core'.
   new T7(0); // Error
          ^" in 0 as{TypeError} core::List<dynamic>);
@@ -116,6 +223,8 @@ library;
 import self as ali;
 import "dart:core" as core;
 
+import "dart:async";
+
 typedef T1 = <T extends core::Object? = dynamic>(T%) → void;
 typedef T2 = (<T extends core::Object? = dynamic>(T%) → void) → void;
 typedef T3 = core::List<<T extends core::Object? = dynamic>(T%) → void>;
@@ -124,6 +233,10 @@ typedef T5 = (<T extends core::Object? = dynamic>(T%) → void, core::int);
 typedef T6 = ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int});
 typedef T7 = ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */;
 typedef T8 = <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void;
+typedef T9 = (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int);
+typedef T10 = ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int});
+typedef T11 = FutureOr<<T extends core::Object? = dynamic>(T%) → void>;
+typedef T12 = FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>;
 class Class<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → ali::Class<ali::Class::T%>
     : super core::Object::•()
@@ -139,7 +252,7 @@ static inline-class-member method ExtensionType|<T extends core::Object? = dynam
 }
 static inline-class-member method ExtensionType|_#new#tearOff<T extends core::Object? = dynamic>(core::List<ali::ExtensionType|_#new#tearOff::T%> it) → ali::ExtensionType<ali::ExtensionType|_#new#tearOff::T%> /* = core::List<ali::ExtensionType|_#new#tearOff::T%> */
   return ali::ExtensionType|<ali::ExtensionType|_#new#tearOff::T%>(it);
-static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   ali::ExtensionType|<dynamic>(<dynamic>[]);
 }
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.outline.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.outline.expect
index 28e76dbfeab..f08855c203a 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.outline.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.outline.expect
@@ -66,13 +66,105 @@ library;
 //   void Function(List<T3>) t3d, // Error
 //                      ^
 //
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:34:3: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   T7 t7a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:35:8: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   List<T7> t7b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:36:17: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T7) t7c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:37:22: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T7>) t7d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:42:3: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T9 t9a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:8: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T9> t9b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:17: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T9) t9c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:22: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T9>) t9d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:3: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T10 t10a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:8: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T10> t10b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:48:17: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T10) t10c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:49:22: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T10>) t10d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:54:3: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T12 t12a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:55:8: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T12> t12b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:56:17: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T12) t12c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:57:22: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T12>) t12d, // Error
+//                      ^
+//
 import self as self;
 import "dart:core" as core;
 import "alias_from_opt_in_lib.dart" as ali;
 
 import "org-dartlang-testcase:///alias_from_opt_in_lib.dart";
 
-static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d) → dynamic
+static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9a, core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)> t9b, ((core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)) → void t9c, (core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)>) → void t9d, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10a, core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})> t10b, (({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})) → void t10c, (core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})>) → void t10d, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11a, core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>> t11b, (FutureOr<<T extends core::Object? = dynamic>(T%) → void>) → void t11c, (core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>>) → void t11d, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12a, core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>> t12b, (FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t12c, (core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>>) → void t12d) → dynamic
   ;
 static method main() → dynamic
   ;
@@ -81,6 +173,8 @@ library;
 import self as ali;
 import "dart:core" as core;
 
+import "dart:async";
+
 typedef T1 = <T extends core::Object? = dynamic>(T%) → void;
 typedef T2 = (<T extends core::Object? = dynamic>(T%) → void) → void;
 typedef T3 = core::List<<T extends core::Object? = dynamic>(T%) → void>;
@@ -89,6 +183,10 @@ typedef T5 = (<T extends core::Object? = dynamic>(T%) → void, core::int);
 typedef T6 = ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int});
 typedef T7 = ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */;
 typedef T8 = <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void;
+typedef T9 = (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int);
+typedef T10 = ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int});
+typedef T11 = FutureOr<<T extends core::Object? = dynamic>(T%) → void>;
+typedef T12 = FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>;
 class Class<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → ali::Class<ali::Class::T%>
     ;
@@ -101,7 +199,7 @@ static inline-class-member method ExtensionType|<T extends core::Object? = dynam
   ;
 static inline-class-member method ExtensionType|_#new#tearOff<T extends core::Object? = dynamic>(core::List<ali::ExtensionType|_#new#tearOff::T%> it) → ali::ExtensionType<ali::ExtensionType|_#new#tearOff::T%> /* = core::List<ali::ExtensionType|_#new#tearOff::T%> */
   return ali::ExtensionType|<ali::ExtensionType|_#new#tearOff::T%>(it);
-static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8) → dynamic
+static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12) → dynamic
   ;
 static method _#T4#new#tearOff<X extends <T extends core::Object? = dynamic>(T%) → void>() → ali::Class<ali::_#T4#new#tearOff::X>
   return new ali::Class::•<ali::_#T4#new#tearOff::X>();
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.transformed.expect b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.transformed.expect
index 089d8b0924d..d529ee36ff2 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart.weak.transformed.expect
@@ -66,43 +66,150 @@ library;
 //   void Function(List<T3>) t3d, // Error
 //                      ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:34:3: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   T7 t7a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:35:8: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   List<T7> t7b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:36:17: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T7) t7c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:37:22: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T7>) t7d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:42:3: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T9 t9a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:8: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T9> t9b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:17: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T9) t9c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:22: Error: Generic function type '(List<void Function<T>(T)>, int)' used as a type argument through typedef 'T9'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T9>) t9d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:3: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T10 t10a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:8: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T10> t10b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:48:17: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T10) t10c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:49:22: Error: Generic function type '({List<void Function<T>(T)> a, int b})' used as a type argument through typedef 'T10'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T10>) t10d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:54:3: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   T12 t12a, // Error,
+//   ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:55:8: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   List<T12> t12b, // Error,
+//        ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:56:17: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(T12) t12c, // Error
+//                 ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:57:22: Error: Generic function type 'FutureOr<List<void Function<T>(T)>>' used as a type argument through typedef 'T12'.
+//  - 'List' is from 'dart:core'.
+// Try providing a non-generic function type explicitly.
+//   void Function(List<T12>) t12d, // Error
+//                      ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
 //  - 'List' is from 'dart:core'.
 //   new T7(0); // Error
 //          ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:43:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:59:7: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   new T4(); // Error
 //       ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:44:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:60:4: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <T4>[]; // Error
 //    ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:45:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:61:18: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(T4)>[]; // Error
 //                  ^
 //
-// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:46:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:62:23: Error: Generic function type 'void Function<T>(T)' inferred as a type argument.
 // Try providing a non-generic function type explicitly.
 //   <void Function(List<T4>)>[]; // Error
 //                       ^
 //
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:64:4: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <T7>[]; // Error
+//    ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:65:18: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(T7)>[]; // Error
+//                  ^
+//
+// pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:66:23: Error: Generic function type 'ExtensionType<void Function<T>(T)>' used as a type argument through typedef 'T7'.
+// Try providing a non-generic function type explicitly.
+//   <void Function(List<T7>)>[]; // Error
+//                       ^
+//
 import self as self;
 import "dart:core" as core;
 import "alias_from_opt_in_lib.dart" as ali;
 
 import "org-dartlang-testcase:///alias_from_opt_in_lib.dart";
 
-static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1a, core::List<<T extends core::Object? = dynamic>(T%) → void> t1b, (<T extends core::Object? = dynamic>(T%) → void) → void t1c, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t1d, (<T extends core::Object? = dynamic>(T%) → void) → void t2a, core::List<(<T extends core::Object? = dynamic>(T%) → void) → void> t2b, ((<T extends core::Object? = dynamic>(T%) → void) → void) → void t2c, (core::List<(<T extends core::Object? = dynamic>(T%) → void) → void>) → void t2d, core::List<<T extends core::Object? = dynamic>(T%) → void> t3a, core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>> t3b, (core::List<<T extends core::Object? = dynamic>(T%) → void>) → void t3c, (core::List<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t3d, ali::Class<<T extends core::Object? = dynamic>(T%) → void> t4a, core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>> t4b, (ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void t4c, (core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void t4d, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5a, core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)> t5b, ((<T extends core::Object? = dynamic>(T%) → void, core::int)) → void t5c, (core::List<(<T extends core::Object? = dynamic>(T%) → void, core::int)>) → void t5d, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6a, core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})> t6b, (({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})) → void t6c, (core::List<({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int})>) → void t6d, ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */ t7a, core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */> t7b, (ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */) → void t7c, (core::List<ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */>) → void t7d, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8a, core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void> t8b, (<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void) → void t8c, (core::List<<S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void>) → void t8d, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9a, core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)> t9b, ((core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)) → void t9c, (core::List<(core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int)>) → void t9d, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10a, core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})> t10b, (({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})) → void t10c, (core::List<({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int})>) → void t10d, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11a, core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>> t11b, (FutureOr<<T extends core::Object? = dynamic>(T%) → void>) → void t11c, (core::List<FutureOr<<T extends core::Object? = dynamic>(T%) → void>>) → void t11d, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12a, core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>> t12b, (FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>) → void t12c, (core::List<FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>>) → void t12d) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   core::_GrowableList::•<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>(0);
   core::_GrowableList::•<(ali::Class<<T extends core::Object? = dynamic>(T%) → void>) → void>(0);
   core::_GrowableList::•<(core::List<ali::Class<<T extends core::Object? = dynamic>(T%) → void>>) → void>(0);
-  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:47:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
+  ali::ExtensionType|<dynamic>(invalid-expression "pkg/front_end/testcases/generic_metadata/alias_from_opt_in.dart:63:10: Error: The argument type 'int' can't be assigned to the parameter type 'List<dynamic>'.
  - 'List' is from 'dart:core'.
   new T7(0); // Error
          ^" in 0 as{TypeError} core::List<dynamic>);
@@ -116,6 +223,8 @@ library;
 import self as ali;
 import "dart:core" as core;
 
+import "dart:async";
+
 typedef T1 = <T extends core::Object? = dynamic>(T%) → void;
 typedef T2 = (<T extends core::Object? = dynamic>(T%) → void) → void;
 typedef T3 = core::List<<T extends core::Object? = dynamic>(T%) → void>;
@@ -124,6 +233,10 @@ typedef T5 = (<T extends core::Object? = dynamic>(T%) → void, core::int);
 typedef T6 = ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int});
 typedef T7 = ali::ExtensionType<<T extends core::Object? = dynamic>(T%) → void> /* = core::List<<T extends core::Object? = dynamic>(T%) → void> */;
 typedef T8 = <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void;
+typedef T9 = (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int);
+typedef T10 = ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int});
+typedef T11 = FutureOr<<T extends core::Object? = dynamic>(T%) → void>;
+typedef T12 = FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>;
 class Class<T extends core::Object? = dynamic> extends core::Object {
   synthetic constructor •() → ali::Class<ali::Class::T%>
     : super core::Object::•()
@@ -139,7 +252,7 @@ static inline-class-member method ExtensionType|<T extends core::Object? = dynam
 }
 static inline-class-member method ExtensionType|_#new#tearOff<T extends core::Object? = dynamic>(core::List<ali::ExtensionType|_#new#tearOff::T%> it) → ali::ExtensionType<ali::ExtensionType|_#new#tearOff::T%> /* = core::List<ali::ExtensionType|_#new#tearOff::T%> */
   return ali::ExtensionType|<ali::ExtensionType|_#new#tearOff::T%>(it);
-static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8) → dynamic {
+static method test(<T extends core::Object? = dynamic>(T%) → void t1, <T extends core::Object? = dynamic>(T%) → void t2, core::List<<T extends core::Object? = dynamic>(T%) → void> t3, (<T extends core::Object? = dynamic>(T%) → void, core::int) t5, ({required a: <T extends core::Object? = dynamic>(T%) → void, required b: core::int}) t6, <S extends <T extends core::Object? = dynamic>(T%) → void = dynamic>(S) → void t8, (core::List<<T extends core::Object? = dynamic>(T%) → void>, core::int) t9, ({required a: core::List<<T extends core::Object? = dynamic>(T%) → void>, required b: core::int}) t10, FutureOr<<T extends core::Object? = dynamic>(T%) → void>t11, FutureOr<core::List<<T extends core::Object? = dynamic>(T%) → void>>t12) → dynamic {
   new ali::Class::•<<T extends core::Object? = dynamic>(T%) → void>();
   ali::ExtensionType|<dynamic>(core::_GrowableList::•<dynamic>(0));
 }
diff --git a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in_lib.dart b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in_lib.dart
index 32c78fb5392..19e801c26c1 100644
--- a/pkg/front_end/testcases/generic_metadata/alias_from_opt_in_lib.dart
+++ b/pkg/front_end/testcases/generic_metadata/alias_from_opt_in_lib.dart
@@ -2,6 +2,8 @@
 // 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.
 
+import 'dart:async';
+
 class Class<T> {}
 
 typedef T1 = void Function<T>(T);
@@ -12,6 +14,10 @@ typedef T5 = (void Function<T>(T), int);
 typedef T6 = ({void Function<T>(T) a, int b});
 typedef T7 = ExtensionType<void Function<T>(T)>;
 typedef T8 = void Function<S extends void Function<T>(T)>(S);
+typedef T9 = (List<void Function<T>(T)>, int);
+typedef T10 = ({List<void Function<T>(T)> a, int b});
+typedef T11 = FutureOr<void Function<T>(T)>;
+typedef T12 = FutureOr<List<void Function<T>(T)>>;
 
 extension type ExtensionType<T>(List<T> it) {}
 
@@ -22,6 +28,10 @@ test(
   T5 t5, // Ok
   T6 t6, // Ok
   T8 t8, // Ok
+  T9 t9, // Ok
+  T10 t10, // Ok
+  T11 t11, // Ok
+  T12 t12, // Ok
 ) {
   new T4(); // Ok
   new T7([]); // Ok
diff --git a/pkg/kernel/lib/src/bounds_checks.dart b/pkg/kernel/lib/src/bounds_checks.dart
index ffb6a068a25..636cf88d449 100644
--- a/pkg/kernel/lib/src/bounds_checks.dart
+++ b/pkg/kernel/lib/src/bounds_checks.dart
@@ -2,17 +2,12 @@
 // 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.
 
-import 'package:kernel/src/replacement_visitor.dart';
-
 import '../ast.dart';
-
 import '../type_algebra.dart' show Substitution, substitute;
-
 import '../type_environment.dart' show SubtypeCheckMode, TypeEnvironment;
-
 import '../util/graph.dart' show Graph, computeStrongComponents;
-
 import 'legacy_erasure.dart';
+import 'replacement_visitor.dart';
 
 class TypeVariableGraph extends Graph<int> {
   @override
@@ -927,7 +922,6 @@ bool hasGenericFunctionTypeAsTypeArgument(DartType type) {
       const _HasGenericFunctionTypeAsTypeArgumentVisitor(), false);
 }
 
-// TODO(johnniwinther): Handle record type and extension type in this visitor.
 class _HasGenericFunctionTypeAsTypeArgumentVisitor
     extends DartTypeVisitor1<bool, bool> {
   const _HasGenericFunctionTypeAsTypeArgumentVisitor();
@@ -940,8 +934,6 @@ class _HasGenericFunctionTypeAsTypeArgumentVisitor
     if (isTypeArgument && node.typeParameters.isNotEmpty) {
       return true;
     }
-    // TODO(johnniwinther): Should deeply nested generic function types be
-    //  disallowed?
     if (node.returnType.accept1(this, false)) return true;
     for (DartType parameterType in node.positionalParameters) {
       if (parameterType.accept1(this, false)) return true;
@@ -949,6 +941,11 @@ class _HasGenericFunctionTypeAsTypeArgumentVisitor
     for (NamedType namedParameterType in node.namedParameters) {
       if (namedParameterType.type.accept1(this, false)) return true;
     }
+    for (TypeParameter typeParameter in node.typeParameters) {
+      if (typeParameter.bound.accept1(this, false)) {
+        return true;
+      }
+    }
     return false;
   }
 
@@ -967,4 +964,52 @@ class _HasGenericFunctionTypeAsTypeArgumentVisitor
     }
     return false;
   }
+
+  @override
+  bool visitExtensionType(ExtensionType node, bool isTypeArgument) {
+    for (DartType typeArgument in node.typeArguments) {
+      if (typeArgument.accept1(this, true)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitDynamicType(DynamicType node, bool isTypeArgument) => false;
+
+  @override
+  bool visitFutureOrType(FutureOrType node, bool isTypeArgument) {
+    return node.typeArgument.accept1(this, false);
+  }
+
+  @override
+  bool visitIntersectionType(IntersectionType node, bool isTypeArgument) {
+    return node.left.accept1(this, false) || node.right.accept1(this, false);
+  }
+
+  @override
+  bool visitInvalidType(InvalidType node, bool isTypeArgument) => false;
+
+  @override
+  bool visitNeverType(NeverType node, bool isTypeArgument) => false;
+
+  @override
+  bool visitNullType(NullType node, bool isTypeArgument) => false;
+
+  @override
+  bool visitRecordType(RecordType node, bool isTypeArgument) {
+    for (DartType parameterType in node.positional) {
+      if (parameterType.accept1(this, false)) return true;
+    }
+    for (NamedType namedParameterType in node.named) {
+      if (namedParameterType.type.accept1(this, false)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitTypeParameterType(TypeParameterType node, bool isTypeArgument) =>
+      false;
+
+  @override
+  bool visitVoidType(VoidType node, bool isTypeArgument) => false;
 }
diff --git a/pkg/kernel/lib/src/find_type_visitor.dart b/pkg/kernel/lib/src/find_type_visitor.dart
new file mode 100644
index 00000000000..20534960833
--- /dev/null
+++ b/pkg/kernel/lib/src/find_type_visitor.dart
@@ -0,0 +1,91 @@
+// Copyright (c) 2023, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE.md file.
+
+import '../ast.dart';
+
+class FindTypeVisitor implements DartTypeVisitor<bool> {
+  const FindTypeVisitor();
+
+  @override
+  bool defaultDartType(DartType node) => false;
+
+  @override
+  bool visitFunctionType(FunctionType node) {
+    if (node.returnType.accept(this)) return true;
+    for (DartType parameterType in node.positionalParameters) {
+      if (parameterType.accept(this)) return true;
+    }
+    for (NamedType namedParameterType in node.namedParameters) {
+      if (namedParameterType.type.accept(this)) return true;
+    }
+    for (TypeParameter parameter in node.typeParameters) {
+      if (parameter.bound.accept(this)) return true;
+      if (parameter.defaultType.accept(this)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitInterfaceType(InterfaceType node) {
+    for (DartType typeArgument in node.typeArguments) {
+      if (typeArgument.accept(this)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitTypedefType(TypedefType node) {
+    for (DartType typeArgument in node.typeArguments) {
+      if (typeArgument.accept(this)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitTypeParameterType(TypeParameterType node) => false;
+
+  @override
+  bool visitIntersectionType(IntersectionType node) {
+    return node.left.accept(this) || node.right.accept(this);
+  }
+
+  @override
+  bool visitDynamicType(DynamicType node) => false;
+
+  @override
+  bool visitExtensionType(ExtensionType node) {
+    for (DartType typeArgument in node.typeArguments) {
+      if (typeArgument.accept(this)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitFutureOrType(FutureOrType node) {
+    return node.typeArgument.accept(this);
+  }
+
+  @override
+  bool visitInvalidType(InvalidType node) => false;
+
+  @override
+  bool visitNeverType(NeverType node) => false;
+
+  @override
+  bool visitNullType(NullType node) => false;
+
+  @override
+  bool visitRecordType(RecordType node) {
+    for (DartType parameterType in node.positional) {
+      if (parameterType.accept(this)) return true;
+    }
+    for (NamedType namedParameterType in node.named) {
+      if (namedParameterType.type.accept(this)) return true;
+    }
+    return false;
+  }
+
+  @override
+  bool visitVoidType(VoidType node) => false;
+}
diff --git a/pkg/kernel/lib/type_algebra.dart b/pkg/kernel/lib/type_algebra.dart
index ebe278734cb..0ae614b4796 100644
--- a/pkg/kernel/lib/type_algebra.dart
+++ b/pkg/kernel/lib/type_algebra.dart
@@ -6,6 +6,7 @@ library kernel.type_algebra;
 
 import 'ast.dart';
 import 'core_types.dart';
+import 'src/find_type_visitor.dart';
 import 'src/replacement_visitor.dart';
 
 /// Returns all free type variables in [type].
@@ -889,7 +890,7 @@ class _DeepTypeSubstitutor extends _InnerTypeSubstitutor {
   }
 }
 
-class _OccurrenceVisitor implements DartTypeVisitor<bool> {
+class _OccurrenceVisitor extends FindTypeVisitor {
   final Set<TypeParameter> variables;
 
   /// Helper function invoked on unknown implementers of [DartType].
@@ -903,7 +904,7 @@ class _OccurrenceVisitor implements DartTypeVisitor<bool> {
 
   _OccurrenceVisitor(this.variables, {this.unhandledTypeHandler});
 
-  bool visit(DartType node) => node.accept(this);
+  bool visit(DartType type) => type.accept(this);
 
   bool visitNamedType(NamedType node) {
     return visit(node.type);
@@ -918,37 +919,6 @@ class _OccurrenceVisitor implements DartTypeVisitor<bool> {
     }
   }
 
-  @override
-  bool visitNeverType(NeverType node) => false;
-  @override
-  bool visitNullType(NullType node) => false;
-  @override
-  bool visitInvalidType(InvalidType node) => false;
-  @override
-  bool visitDynamicType(DynamicType node) => false;
-  @override
-  bool visitVoidType(VoidType node) => false;
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    return node.typeArguments.any(visit);
-  }
-
-  @override
-  bool visitExtensionType(ExtensionType node) {
-    return node.typeArguments.any(visit);
-  }
-
-  @override
-  bool visitFutureOrType(FutureOrType node) {
-    return visit(node.typeArgument);
-  }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    return node.typeArguments.any(visit);
-  }
-
   @override
   bool visitFunctionType(FunctionType node) {
     return node.typeParameters.any(handleTypeParameter) ||
@@ -957,21 +927,11 @@ class _OccurrenceVisitor implements DartTypeVisitor<bool> {
         visit(node.returnType);
   }
 
-  @override
-  bool visitRecordType(RecordType node) {
-    return node.positional.any(visit) || node.named.any(visitNamedType);
-  }
-
   @override
   bool visitTypeParameterType(TypeParameterType node) {
     return variables.contains(node.parameter);
   }
 
-  @override
-  bool visitIntersectionType(IntersectionType node) {
-    return visit(node.left) || visit(node.right);
-  }
-
   bool handleTypeParameter(TypeParameter node) {
     assert(!variables.contains(node));
     if (node.bound.accept(this)) return true;
@@ -979,166 +939,48 @@ class _OccurrenceVisitor implements DartTypeVisitor<bool> {
   }
 }
 
-class _FreeFunctionTypeVariableVisitor implements DartTypeVisitor<bool> {
+class _FreeFunctionTypeVariableVisitor extends FindTypeVisitor {
   final Set<TypeParameter> variables = new Set<TypeParameter>();
 
   _FreeFunctionTypeVariableVisitor();
 
   bool visit(DartType node) => node.accept(this);
 
-  @override
-  bool defaultDartType(DartType node) {
-    throw new UnsupportedError("Unsupported type $node (${node.runtimeType}).");
-  }
-
-  bool visitNamedType(NamedType node) {
-    return visit(node.type);
-  }
-
-  @override
-  bool visitNeverType(NeverType node) => false;
-  @override
-  bool visitNullType(NullType node) => false;
-  @override
-  bool visitInvalidType(InvalidType node) => false;
-  @override
-  bool visitDynamicType(DynamicType node) => false;
-  @override
-  bool visitVoidType(VoidType node) => false;
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    return node.typeArguments.any(visit);
-  }
-
-  @override
-  bool visitExtensionType(ExtensionType node) {
-    return node.typeArguments.any(visit);
-  }
-
-  @override
-  bool visitFutureOrType(FutureOrType node) {
-    return visit(node.typeArgument);
-  }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    return node.typeArguments.any(visit);
-  }
-
   @override
   bool visitFunctionType(FunctionType node) {
     variables.addAll(node.typeParameters);
-    bool result = node.typeParameters.any(handleTypeParameter) ||
-        node.positionalParameters.any(visit) ||
-        node.namedParameters.any(visitNamedType) ||
-        visit(node.returnType);
+    bool result = super.visitFunctionType(node);
     variables.removeAll(node.typeParameters);
     return result;
   }
 
-  @override
-  bool visitRecordType(RecordType node) {
-    return node.positional.any(visit) || node.named.any(visitNamedType);
-  }
-
   @override
   bool visitTypeParameterType(TypeParameterType node) {
     return node.parameter.declaration == null &&
         !variables.contains(node.parameter);
   }
-
-  @override
-  bool visitIntersectionType(IntersectionType node) {
-    return visit(node.left) || visit(node.right);
-  }
-
-  bool handleTypeParameter(TypeParameter node) {
-    assert(variables.contains(node));
-    if (node.bound.accept(this)) return true;
-    return node.defaultType.accept(this);
-  }
 }
 
-class _FreeTypeVariableVisitor implements DartTypeVisitor<bool> {
+class _FreeTypeVariableVisitor extends FindTypeVisitor {
   final Set<TypeParameter> boundVariables;
 
   _FreeTypeVariableVisitor({Set<TypeParameter>? boundVariables})
       : this.boundVariables = boundVariables ?? <TypeParameter>{};
 
-  bool visit(DartType node) => node.accept(this);
-
-  @override
-  bool defaultDartType(DartType node) {
-    throw new UnsupportedError("Unsupported type $node (${node.runtimeType}.");
-  }
-
-  bool visitNamedType(NamedType node) {
-    return visit(node.type);
-  }
-
-  @override
-  bool visitNeverType(NeverType node) => false;
-  @override
-  bool visitNullType(NullType node) => false;
-  @override
-  bool visitInvalidType(InvalidType node) => false;
-  @override
-  bool visitDynamicType(DynamicType node) => false;
-  @override
-  bool visitVoidType(VoidType node) => false;
-
-  @override
-  bool visitInterfaceType(InterfaceType node) {
-    return node.typeArguments.any(visit);
-  }
-
-  @override
-  bool visitExtensionType(ExtensionType node) {
-    return node.typeArguments.any(visit);
-  }
-
-  @override
-  bool visitFutureOrType(FutureOrType node) {
-    return visit(node.typeArgument);
-  }
-
-  @override
-  bool visitTypedefType(TypedefType node) {
-    return node.typeArguments.any(visit);
-  }
+  bool visit(DartType type) => type.accept(this);
 
   @override
   bool visitFunctionType(FunctionType node) {
     boundVariables.addAll(node.typeParameters);
-    bool result = node.typeParameters.any(handleTypeParameter) ||
-        node.positionalParameters.any(visit) ||
-        node.namedParameters.any(visitNamedType) ||
-        visit(node.returnType);
+    bool result = super.visitFunctionType(node);
     boundVariables.removeAll(node.typeParameters);
     return result;
   }
 
-  @override
-  bool visitRecordType(RecordType node) {
-    return node.positional.any(visit) || node.named.any(visitNamedType);
-  }
-
   @override
   bool visitTypeParameterType(TypeParameterType node) {
     return !boundVariables.contains(node.parameter);
   }
-
-  @override
-  bool visitIntersectionType(IntersectionType node) {
-    return visit(node.left) && visit(node.right);
-  }
-
-  bool handleTypeParameter(TypeParameter node) {
-    assert(boundVariables.contains(node));
-    if (node.bound.accept(this)) return true;
-    return node.defaultType.accept(this);
-  }
 }
 
 Nullability uniteNullabilities(Nullability a, Nullability b) {
diff --git a/pkg/kernel/lib/visitor.dart b/pkg/kernel/lib/visitor.dart
index 6a3deb1a9d9..3e28ea78525 100644
--- a/pkg/kernel/lib/visitor.dart
+++ b/pkg/kernel/lib/visitor.dart
@@ -901,42 +901,108 @@ abstract class TreeVisitor1<R, A>
 abstract class DartTypeVisitor<R> {
   const DartTypeVisitor();
 
+  // TODO(johnniwinther): Remove this.
   R defaultDartType(DartType node);
 
+  R visitInvalidType(InvalidType node);
+  R visitDynamicType(DynamicType node);
+  R visitVoidType(VoidType node);
+  R visitInterfaceType(InterfaceType node);
+  R visitFutureOrType(FutureOrType node);
+  R visitFunctionType(FunctionType node);
+  R visitTypeParameterType(TypeParameterType node);
+  R visitTypedefType(TypedefType node);
+  R visitNeverType(NeverType node);
+  R visitNullType(NullType node);
+  R visitExtensionType(ExtensionType node);
+  R visitIntersectionType(IntersectionType node);
+  R visitRecordType(RecordType node);
+}
+
+mixin DartTypeVisitorDefaultMixin<R> implements DartTypeVisitor<R> {
+  @override
+  R defaultDartType(DartType node);
+
+  @override
   R visitInvalidType(InvalidType node) => defaultDartType(node);
+  @override
   R visitDynamicType(DynamicType node) => defaultDartType(node);
+  @override
   R visitVoidType(VoidType node) => defaultDartType(node);
+  @override
   R visitInterfaceType(InterfaceType node) => defaultDartType(node);
+  @override
   R visitFutureOrType(FutureOrType node) => defaultDartType(node);
+  @override
   R visitFunctionType(FunctionType node) => defaultDartType(node);
+  @override
   R visitTypeParameterType(TypeParameterType node) => defaultDartType(node);
+  @override
   R visitTypedefType(TypedefType node) => defaultDartType(node);
+  @override
   R visitNeverType(NeverType node) => defaultDartType(node);
+  @override
   R visitNullType(NullType node) => defaultDartType(node);
+  @override
   R visitExtensionType(ExtensionType node) => defaultDartType(node);
+  @override
   R visitIntersectionType(IntersectionType node) => defaultDartType(node);
+  @override
   R visitRecordType(RecordType node) => defaultDartType(node);
 }
 
 abstract class DartTypeVisitor1<R, A> {
   const DartTypeVisitor1();
 
+  // TODO(johnniwinther): Remove this.
   R defaultDartType(DartType node, A arg);
 
+  R visitInvalidType(InvalidType node, A arg);
+  R visitDynamicType(DynamicType node, A arg);
+  R visitVoidType(VoidType node, A arg);
+  R visitInterfaceType(InterfaceType node, A arg);
+  R visitFutureOrType(FutureOrType node, A arg);
+  R visitFunctionType(FunctionType node, A arg);
+  R visitTypeParameterType(TypeParameterType node, A arg);
+  R visitTypedefType(TypedefType node, A arg);
+  R visitNeverType(NeverType node, A arg);
+  R visitNullType(NullType node, A arg);
+  R visitExtensionType(ExtensionType node, A arg);
+  R visitIntersectionType(IntersectionType node, A arg);
+  R visitRecordType(RecordType node, A arg);
+}
+
+mixin DartTypeVisitor1DefaultMixin<R, A> implements DartTypeVisitor1<R, A> {
+  @override
+  R defaultDartType(DartType node, A arg);
+
+  @override
   R visitInvalidType(InvalidType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitDynamicType(DynamicType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitVoidType(VoidType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitInterfaceType(InterfaceType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitFutureOrType(FutureOrType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitFunctionType(FunctionType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitTypeParameterType(TypeParameterType node, A arg) =>
       defaultDartType(node, arg);
+  @override
   R visitTypedefType(TypedefType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitNeverType(NeverType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitNullType(NullType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitExtensionType(ExtensionType node, A arg) => defaultDartType(node, arg);
+  @override
   R visitIntersectionType(IntersectionType node, A arg) =>
       defaultDartType(node, arg);
+  @override
   R visitRecordType(RecordType node, A arg) => defaultDartType(node, arg);
 }
 
diff --git a/pkg/vm/lib/transformations/type_flow/summary_collector.dart b/pkg/vm/lib/transformations/type_flow/summary_collector.dart
index a80592f77dd..4279a9aeb9d 100644
--- a/pkg/vm/lib/transformations/type_flow/summary_collector.dart
+++ b/pkg/vm/lib/transformations/type_flow/summary_collector.dart
@@ -2505,6 +2505,7 @@ class SummaryCollector extends RecursiveResultVisitor<TypeExpr?> {
 }
 
 class RuntimeTypeTranslatorImpl extends DartTypeVisitor<TypeExpr>
+    with DartTypeVisitorDefaultMixin<TypeExpr>
     implements RuntimeTypeTranslator {
   final CoreTypes coreTypes;
   final Summary? summary;