[cfe] Add Jenkins SMI hashcode combiner

Change-Id: I542369fc2d8443bb0094fdedc11596fdc2f20e2d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/159084
Commit-Queue: Javier López-Contreras <jlcontreras@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
Reviewed-by: Dmitry Stefantsov <dmitryas@google.com>

pkg/front_end/test/spell_checking_list_tests.txt

@@ -335,6 +335,7 @@ issue41499b
 it'll
 italic
 iter
+jlcontreras
 joo
 jumped
 kernels

pkg/front_end/testcases/strong.status

@@ -254,4 +254,5 @@ runtime_checks_new/mixin_forwarding_stub_getter: TypeCheckError
 runtime_checks_new/mixin_forwarding_stub_setter: TypeCheckError
 set_literals/disambiguation_rule: RuntimeError
 value_class/simple: RuntimeError # Expected
-value_class/super_type: RuntimeError # Expected
+value_class/value_extends_non_value: RuntimeError # Expected
+value_class/value_implements_non_value: RuntimeError # Expected

pkg/front_end/testcases/text_serialization.status

@@ -251,5 +251,5 @@ runtime_checks_new/mixin_forwarding_stub_field: TypeCheckError
 runtime_checks_new/mixin_forwarding_stub_setter: TypeCheckError
 set_literals/disambiguation_rule: RuntimeError
 value_class/simple: RuntimeError # Expected
-value_class/super_type: RuntimeError # Expected
-
+value_class/value_extends_non_value: RuntimeError # Expected
+value_class/value_implements_non_value: RuntimeError # Expected

pkg/front_end/testcases/value_class/empty.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class EmptyClass {}

pkg/front_end/testcases/value_class/empty.dart.outline.expect

@@ -1,12 +1,28 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class EmptyClass extends core::Object {
   synthetic constructor •() → self::EmptyClass
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/empty.dart.strong.expect

@@ -2,14 +2,36 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class EmptyClass extends core::Object {
   synthetic constructor •() → self::EmptyClass
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/empty.dart.strong.transformed.expect

@@ -2,14 +2,36 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class EmptyClass extends core::Object {
   synthetic constructor •() → self::EmptyClass
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/empty.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class EmptyClass {}

pkg/front_end/testcases/value_class/empty.dart.textual_outline_modelled.expect

@@ -1,5 +1,6 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class EmptyClass {}
 
-const String valueClass = "valueClass";
 main() {}

pkg/front_end/testcases/value_class/empty.dart.weak.expect

@@ -2,14 +2,36 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class EmptyClass extends core::Object {
   synthetic constructor •() → self::EmptyClass
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/empty.dart.weak.transformed.expect

@@ -2,14 +2,36 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class EmptyClass extends core::Object {
   synthetic constructor •() → self::EmptyClass
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/explicit_mixin.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class A {}

pkg/front_end/testcases/value_class/explicit_mixin.dart.outline.expect

@@ -1,8 +1,11 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class A extends core::Object {
   synthetic constructor •() → self::A
     ;
@@ -25,12 +28,25 @@ class E = self::B with self::A {
     : super self::B::•()
     ;
 }
-@self::valueClass
+@val::valueClass
 class F = self::B with self::C {
   synthetic constructor •() → self::F
     : super self::B::•()
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/explicit_mixin.dart.strong.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class F = self::B with self::C {
     : super self::B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/explicit_mixin.dart.strong.transformed.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class F extends self::B implements self::C /*isEliminatedMixin*/  {
     : super self::B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/explicit_mixin.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class A {}

pkg/front_end/testcases/value_class/explicit_mixin.dart.textual_outline_modelled.expect

@@ -1,3 +1,5 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class A {}
 
@@ -9,5 +11,4 @@ class D = A with B;
 class E = B with A;
 @valueClass
 class F = B with C;
-const String valueClass = "valueClass";
 main() {}

pkg/front_end/testcases/value_class/explicit_mixin.dart.weak.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class F = self::B with self::C {
     : super self::B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/explicit_mixin.dart.weak.transformed.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class F extends self::B implements self::C /*isEliminatedMixin*/  {
     : super self::B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_final_field_error.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

pkg/front_end/testcases/value_class/non_final_field_error.dart.outline.expect

@@ -1,13 +1,29 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class Animal extends core::Object {
   field core::int numberOfLegs;
   synthetic constructor •() → self::Animal
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/non_final_field_error.dart.strong.expect

@@ -9,15 +9,37 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_final_field_error.dart.strong.transformed.expect

@@ -9,15 +9,37 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_final_field_error.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

pkg/front_end/testcases/value_class/non_final_field_error.dart.textual_outline_modelled.expect

@@ -1,7 +1,8 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class Animal {
   int numberOfLegs;
 }
 
-const String valueClass = "valueClass";
 main() {}

pkg/front_end/testcases/value_class/non_final_field_error.dart.weak.expect

@@ -9,15 +9,37 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_final_field_error.dart.weak.transformed.expect

@@ -9,15 +9,37 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.outline.expect

@@ -1,8 +1,11 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   synthetic constructor •() → self::Animal
@@ -12,6 +15,19 @@ class Cat extends self::Animal {
   synthetic constructor •() → self::Cat
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.strong.expect

@@ -10,6 +10,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -21,9 +23,29 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.strong.transformed.expect

@@ -10,6 +10,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -21,9 +23,29 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.textual_outline_modelled.expect

@@ -1,3 +1,5 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class Animal {
   final int numberOfLegs;
@@ -5,5 +7,4 @@ class Animal {
 
 class Cat extends Animal {}
 
-const String valueClass = "valueClass";
 main() {}

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.weak.expect

@@ -10,6 +10,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -21,9 +23,29 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_extends_value_error.dart.weak.transformed.expect

@@ -10,6 +10,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -21,9 +23,29 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.outline.expect

@@ -1,8 +1,11 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   synthetic constructor •() → self::Animal
@@ -13,6 +16,19 @@ class Cat extends core::Object implements self::Animal {
   synthetic constructor •() → self::Cat
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.strong.expect

@@ -15,6 +15,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -27,9 +29,29 @@ class Cat extends core::Object implements self::Animal {
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.strong.transformed.expect

@@ -15,6 +15,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -27,9 +29,29 @@ class Cat extends core::Object implements self::Animal {
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.textual_outline_modelled.expect

@@ -1,3 +1,5 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class Animal {
   final int numberOfLegs;
@@ -7,5 +9,4 @@ class Cat implements Animal {
   final int numberOfLegs;
 }
 
-const String valueClass = "valueClass";
 main() {}

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.weak.expect

@@ -15,6 +15,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -27,9 +29,29 @@ class Cat extends core::Object implements self::Animal {
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/non_value_implements_value_error.dart.weak.transformed.expect

@@ -15,6 +15,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
@@ -27,9 +29,29 @@ class Cat extends core::Object implements self::Animal {
     : super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/simple.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {
@@ -21,11 +21,6 @@ main() {
   expect(false, firstAnimal.hashCode == thirdAnimal.hashCode);
 }
 
-expect(expected, actual, [expectNull = false]) {
-  if (expectNull) {
-    expected = null;
-  }
-  if (expected != actual) {
-    throw 'Mismatch: expected=$expected, actual=$actual';
-  }
+expect(Object? expected, Object? actual) {
+  if (expected != actual) throw 'Expected=$expected, actual=$actual';
 }

pkg/front_end/testcases/value_class/simple.dart.outline.expect

@@ -1,15 +1,31 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   synthetic constructor •() → self::Animal
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull]) → dynamic
+static method expect(core::Object? expected, core::Object? actual) → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/simple.dart.strong.expect

@@ -31,13 +31,14 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {
   self::Animal firstAnimal = invalid-expression "pkg/front_end/testcases/value_class/simple.dart:13:31: Error: No named parameter with the name 'numberOfLegs'.
   Animal firstAnimal = Animal(numberOfLegs: 4);
@@ -53,16 +54,32 @@ static method main() → dynamic {
   self::expect(true, firstAnimal.{core::Object::hashCode}.{core::num::==}(secondAnimal.{core::Object::hashCode}));
   self::expect(false, firstAnimal.{core::Object::hashCode}.{core::num::==}(thirdAnimal.{core::Object::hashCode}));
 }
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
   }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
   }
 }
+static const field core::String valueClass = #C1;
 
 constants  {
   #C1 = "valueClass"
-  #C2 = false
 }

pkg/front_end/testcases/value_class/simple.dart.strong.transformed.expect

@@ -31,13 +31,14 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {
   self::Animal firstAnimal = invalid-expression "pkg/front_end/testcases/value_class/simple.dart:13:31: Error: No named parameter with the name 'numberOfLegs'.
   Animal firstAnimal = Animal(numberOfLegs: 4);
@@ -53,16 +54,32 @@ static method main() → dynamic {
   self::expect(true, firstAnimal.{core::Object::hashCode}.{core::num::==}(secondAnimal.{core::Object::hashCode}));
   self::expect(false, firstAnimal.{core::Object::hashCode}.{core::num::==}(thirdAnimal.{core::Object::hashCode}));
 }
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
   }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
   }
 }
+static const field core::String valueClass = #C1;
 
 constants  {
   #C1 = "valueClass"
-  #C2 = false
 }

pkg/front_end/testcases/value_class/simple.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {
@@ -6,4 +6,4 @@ class Animal {
 }
 
 main() {}
-expect(expected, actual, [expectNull = false]) {}
+expect(Object? expected, Object? actual) {}

pkg/front_end/testcases/value_class/simple.dart.textual_outline_modelled.expect

@@ -1,8 +1,9 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class Animal {
   final int numberOfLegs;
 }
 
-const String valueClass = "valueClass";
-expect(expected, actual, [expectNull = false]) {}
+expect(Object? expected, Object? actual) {}
 main() {}

pkg/front_end/testcases/value_class/simple.dart.weak.expect

@@ -31,13 +31,14 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {
   self::Animal firstAnimal = invalid-expression "pkg/front_end/testcases/value_class/simple.dart:13:31: Error: No named parameter with the name 'numberOfLegs'.
   Animal firstAnimal = Animal(numberOfLegs: 4);
@@ -53,16 +54,32 @@ static method main() → dynamic {
   self::expect(true, firstAnimal.{core::Object::hashCode}.{core::num::==}(secondAnimal.{core::Object::hashCode}));
   self::expect(false, firstAnimal.{core::Object::hashCode}.{core::num::==}(thirdAnimal.{core::Object::hashCode}));
 }
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
   }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
   }
 }
+static const field core::String valueClass = #C1;
 
 constants  {
   #C1 = "valueClass"
-  #C2 = false
 }

pkg/front_end/testcases/value_class/simple.dart.weak.transformed.expect

@@ -31,13 +31,14 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •({required core::int numberOfLegs}) → self::Animal
     : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {
   self::Animal firstAnimal = invalid-expression "pkg/front_end/testcases/value_class/simple.dart:13:31: Error: No named parameter with the name 'numberOfLegs'.
   Animal firstAnimal = Animal(numberOfLegs: 4);
@@ -53,16 +54,32 @@ static method main() → dynamic {
   self::expect(true, firstAnimal.{core::Object::hashCode}.{core::num::==}(secondAnimal.{core::Object::hashCode}));
   self::expect(false, firstAnimal.{core::Object::hashCode}.{core::num::==}(thirdAnimal.{core::Object::hashCode}));
 }
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
   }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
   }
 }
+static const field core::String valueClass = #C1;
 
 constants  {
   #C1 = "valueClass"
-  #C2 = false
 }

pkg/front_end/testcases/value_class/super_type.dart

@@ -1,37 +0,0 @@
-// Copyright (c) 2020, 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 file.
-
-const String valueClass = "valueClass";
-
-@valueClass
-class Animal {
-  final int numberOfLegs;
-}
-
-@valueClass
-class Cat implements Animal {
-  final int numberOfLegs;
-  final int numberOfWhiskers;
-}
-
-main() {
-  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-
-  expect(true, firstCat == secondCat);
-  expect(false, firstCat == thirdCat);
-
-  expect(true, firstCat.hashCode == secondCat.hashCode);
-  expect(false, firstCat.hashCode == thirdCat.hashCode);
-}
-
-expect(expected, actual, [expectNull = false]) {
-  if (expectNull) {
-    expected = null;
-  }
-  if (expected != actual) {
-    throw 'Mismatch: expected=$expected, actual=$actual';
-  }
-}

pkg/front_end/testcases/value_class/super_type.dart.outline.expect

@@ -1,22 +0,0 @@
-library /*isNonNullableByDefault*/;
-import self as self;
-import "dart:core" as core;
-
-@self::valueClass
-class Animal extends core::Object {
-  final field core::int numberOfLegs;
-  synthetic constructor •() → self::Animal
-    ;
-}
-@self::valueClass
-class Cat extends core::Object implements self::Animal {
-  final field core::int numberOfLegs;
-  final field core::int numberOfWhiskers;
-  synthetic constructor •() → self::Cat
-    ;
-}
-static const field core::String valueClass = "valueClass";
-static method main() → dynamic
-  ;
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull]) → dynamic
-  ;

pkg/front_end/testcases/value_class/super_type.dart.strong.expect

@@ -1,85 +0,0 @@
-library /*isNonNullableByDefault*/;
-//
-// Problems in library:
-//
-// pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                       ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfWhiskers;
-//             ^^^^^^^^^^^^^^^^
-//
-import self as self;
-import "dart:core" as core;
-
-class Animal extends core::Object {
-  final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Animal
-    : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
-    ;
-}
-class Cat extends core::Object implements self::Animal {
-  final field core::int numberOfLegs = null;
-  final field core::int numberOfWhiskers = null;
-  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
-    ;
-}
-static const field core::String valueClass = #C1;
-static method main() → dynamic {
-  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
-  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                      ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
-  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
-  self::expect(true, firstCat.{core::Object::==}(secondCat));
-  self::expect(false, firstCat.{core::Object::==}(thirdCat));
-  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
-  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
-}
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
-  }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
-  }
-}
-
-constants  {
-  #C1 = "valueClass"
-  #C2 = false
-}

pkg/front_end/testcases/value_class/super_type.dart.strong.transformed.expect

@@ -1,85 +0,0 @@
-library /*isNonNullableByDefault*/;
-//
-// Problems in library:
-//
-// pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                       ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfWhiskers;
-//             ^^^^^^^^^^^^^^^^
-//
-import self as self;
-import "dart:core" as core;
-
-class Animal extends core::Object {
-  final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Animal
-    : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
-    ;
-}
-class Cat extends core::Object implements self::Animal {
-  final field core::int numberOfLegs = null;
-  final field core::int numberOfWhiskers = null;
-  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
-    ;
-}
-static const field core::String valueClass = #C1;
-static method main() → dynamic {
-  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                     ^^^^^^^^^^^^";
-  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                      ^^^^^^^^^^^^";
-  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-                     ^^^^^^^^^^^^";
-  self::expect(true, firstCat.{core::Object::==}(secondCat));
-  self::expect(false, firstCat.{core::Object::==}(thirdCat));
-  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
-  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
-}
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
-  }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
-  }
-}
-
-constants  {
-  #C1 = "valueClass"
-  #C2 = false
-}

pkg/front_end/testcases/value_class/super_type.dart.textual_outline.expect

@@ -1,15 +0,0 @@
-const String valueClass = "valueClass";
-
-@valueClass
-class Animal {
-  final int numberOfLegs;
-}
-
-@valueClass
-class Cat implements Animal {
-  final int numberOfLegs;
-  final int numberOfWhiskers;
-}
-
-main() {}
-expect(expected, actual, [expectNull = false]) {}

pkg/front_end/testcases/value_class/super_type.dart.textual_outline_modelled.expect

@@ -1,14 +0,0 @@
-@valueClass
-class Animal {
-  final int numberOfLegs;
-}
-
-@valueClass
-class Cat implements Animal {
-  final int numberOfLegs;
-  final int numberOfWhiskers;
-}
-
-const String valueClass = "valueClass";
-expect(expected, actual, [expectNull = false]) {}
-main() {}

pkg/front_end/testcases/value_class/super_type.dart.weak.expect

@@ -1,85 +0,0 @@
-library /*isNonNullableByDefault*/;
-//
-// Problems in library:
-//
-// pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                       ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfWhiskers;
-//             ^^^^^^^^^^^^^^^^
-//
-import self as self;
-import "dart:core" as core;
-
-class Animal extends core::Object {
-  final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Animal
-    : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
-    ;
-}
-class Cat extends core::Object implements self::Animal {
-  final field core::int numberOfLegs = null;
-  final field core::int numberOfWhiskers = null;
-  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
-    ;
-}
-static const field core::String valueClass = #C1;
-static method main() → dynamic {
-  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
-  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                      ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
-  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
-  self::expect(true, firstCat.{core::Object::==}(secondCat));
-  self::expect(false, firstCat.{core::Object::==}(thirdCat));
-  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
-  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
-}
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
-  }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
-  }
-}
-
-constants  {
-  #C1 = "valueClass"
-  #C2 = false
-}

pkg/front_end/testcases/value_class/super_type.dart.weak.transformed.expect

@@ -1,85 +0,0 @@
-library /*isNonNullableByDefault*/;
-//
-// Problems in library:
-//
-// pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-//                       ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-//                      ^^^^^^^^^^^^
-// pkg/front_end/testcases/value_class/super_type.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
-// class Cat implements Animal {
-//       ^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfLegs;
-//             ^^^^^^^^^^^^
-//
-// pkg/front_end/testcases/value_class/super_type.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
-// Try to initialize the field in the declaration or in every constructor.
-//   final int numberOfWhiskers;
-//             ^^^^^^^^^^^^^^^^
-//
-import self as self;
-import "dart:core" as core;
-
-class Animal extends core::Object {
-  final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Animal
-    : self::Animal::numberOfLegs = numberOfLegs, super core::Object::•()
-    ;
-}
-class Cat extends core::Object implements self::Animal {
-  final field core::int numberOfLegs = null;
-  final field core::int numberOfWhiskers = null;
-  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
-    ;
-}
-static const field core::String valueClass = #C1;
-static method main() → dynamic {
-  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:19:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                     ^^^^^^^^^^^^";
-  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:20:23: Error: No named parameter with the name 'numberOfLegs'.
-  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
-                      ^^^^^^^^^^^^";
-  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/super_type.dart:21:22: Error: No named parameter with the name 'numberOfLegs'.
-  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
-                     ^^^^^^^^^^^^";
-  self::expect(true, firstCat.{core::Object::==}(secondCat));
-  self::expect(false, firstCat.{core::Object::==}(thirdCat));
-  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
-  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
-}
-static method expect(dynamic expected, dynamic actual, [dynamic expectNull = #C2]) → dynamic {
-  if(expectNull as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool) {
-    expected = null;
-  }
-  if(!expected.{core::Object::==}(actual)) {
-    throw "Mismatch: expected=${expected}, actual=${actual}";
-  }
-}
-
-constants  {
-  #C1 = "valueClass"
-  #C2 = false
-}

pkg/front_end/testcases/value_class/value_class_support_lib.dart

@@ -0,0 +1,22 @@
+// Copyright (c) 2020, 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 file.
+
+// TODO(jlcontreras): this is a temp file for the valueClass experiment
+
+const valueClass = "valueClass";
+
+/// This code is from the dart.math sdk/lib/math/jenkins_smi_hash.dart
+class JenkinsSmiHash {
+  static int combine(int hash, int value) {
+    hash = 0x1fffffff & (hash + value);
+    hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+    return hash ^ (hash >> 6);
+  }
+
+  static int finish(int hash) {
+    hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+    hash = hash ^ (hash >> 11);
+    return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+  }
+}

pkg/front_end/testcases/value_class/value_extends_non_value.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 class Animal {
   final int numberOfLegs;
@@ -14,4 +14,18 @@ class Cat extends Animal {
   final int numberOfWhiskers;
 }
 
-main() {}
+main() {
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+
+  expect(true, firstCat == secondCat);
+  expect(false, firstCat == thirdCat);
+
+  expect(true, firstCat.hashCode == secondCat.hashCode);
+  expect(false, firstCat.hashCode == thirdCat.hashCode);
+}
+
+expect(Object? expected, Object? actual) {
+  if (expected != actual) throw 'Expected=$expected, actual=$actual';
+}

pkg/front_end/testcases/value_class/value_extends_non_value.dart.outline.expect

@@ -1,18 +1,36 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
+import "value_class_support_lib.dart" as val;
+
+import "org-dartlang-testcase:///value_class_support_lib.dart";
 
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   constructor •({required core::int numberOfLegs}) → self::Animal
     ;
 }
-@self::valueClass
+@val::valueClass
 class Cat extends self::Animal {
   final field core::int numberOfWhiskers;
   synthetic constructor •() → self::Cat
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+static method expect(core::Object? expected, core::Object? actual) → dynamic
+  ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/value_extends_non_value.dart.strong.expect

@@ -2,6 +2,27 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
 // pkg/front_end/testcases/value_class/value_extends_non_value.dart:14:13: Error: Final field 'numberOfWhiskers' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfWhiskers;
@@ -10,6 +31,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   constructor •({required core::int numberOfLegs = #C1}) → self::Animal
@@ -22,8 +45,46 @@ class Cat extends self::Animal {
     : self::Cat::numberOfWhiskers = numberOfWhiskers, super self::Animal::•(numberOfLegs)
     ;
 }
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C2;
-static method main() → dynamic {}
 
 constants  {
   #C1 = null

pkg/front_end/testcases/value_class/value_extends_non_value.dart.strong.transformed.expect

@@ -2,6 +2,27 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
 // pkg/front_end/testcases/value_class/value_extends_non_value.dart:14:13: Error: Final field 'numberOfWhiskers' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfWhiskers;
@@ -10,6 +31,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   constructor •({required core::int numberOfLegs = #C1}) → self::Animal
@@ -22,8 +45,46 @@ class Cat extends self::Animal {
     : self::Cat::numberOfWhiskers = numberOfWhiskers, super self::Animal::•(numberOfLegs)
     ;
 }
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^";
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^";
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^";
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C2;
-static method main() → dynamic {}
 
 constants  {
   #C1 = null

pkg/front_end/testcases/value_class/value_extends_non_value.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 class Animal {
   final int numberOfLegs;
@@ -11,3 +11,4 @@ class Cat extends Animal {
 }
 
 main() {}
+expect(Object? expected, Object? actual) {}

pkg/front_end/testcases/value_class/value_extends_non_value.dart.textual_outline_modelled.expect

@@ -1,3 +1,5 @@
+import 'value_class_support_lib.dart';
+
 class Animal {
   Animal({required this.numberOfLegs});
   final int numberOfLegs;
@@ -8,5 +10,5 @@ class Cat extends Animal {
   final int numberOfWhiskers;
 }
 
-const String valueClass = "valueClass";
+expect(Object? expected, Object? actual) {}
 main() {}

pkg/front_end/testcases/value_class/value_extends_non_value.dart.weak.expect

@@ -2,6 +2,27 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
 // pkg/front_end/testcases/value_class/value_extends_non_value.dart:14:13: Error: Final field 'numberOfWhiskers' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfWhiskers;
@@ -10,6 +31,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   constructor •({required core::int numberOfLegs = #C1}) → self::Animal
@@ -22,8 +45,46 @@ class Cat extends self::Animal {
     : self::Cat::numberOfWhiskers = numberOfWhiskers, super self::Animal::•(numberOfLegs)
     ;
 }
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C2;
-static method main() → dynamic {}
 
 constants  {
   #C1 = null

pkg/front_end/testcases/value_class/value_extends_non_value.dart.weak.transformed.expect

@@ -2,6 +2,27 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_extends_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat extends Animal {
+//       ^
+//
 // pkg/front_end/testcases/value_class/value_extends_non_value.dart:14:13: Error: Final field 'numberOfWhiskers' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfWhiskers;
@@ -10,6 +31,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   constructor •({required core::int numberOfLegs = #C1}) → self::Animal
@@ -22,8 +45,46 @@ class Cat extends self::Animal {
     : self::Cat::numberOfWhiskers = numberOfWhiskers, super self::Animal::•(numberOfLegs)
     ;
 }
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:18:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^";
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:19:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^";
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_extends_non_value.dart:20:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^";
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C2;
-static method main() → dynamic {}
 
 constants  {
   #C1 = null

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 class Animal {
   int numberOfLegs;
@@ -11,4 +11,11 @@ class Animal {
 @valueClass
 class Cat extends Animal {}
 
+class Animal2 {
+  final int numberOfLegs;
+}
+
+@valueClass
+class Cat2 extends Animal2 {}
+
 main() {}

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.outline.expect

@@ -1,17 +1,43 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
+import "value_class_support_lib.dart" as val;
+
+import "org-dartlang-testcase:///value_class_support_lib.dart";
 
 class Animal extends core::Object {
   field core::int numberOfLegs;
   synthetic constructor •() → self::Animal
     ;
 }
-@self::valueClass
+@val::valueClass
 class Cat extends self::Animal {
   synthetic constructor •() → self::Cat
     ;
 }
-static const field core::String valueClass = "valueClass";
+class Animal2 extends core::Object {
+  final field core::int numberOfLegs;
+  synthetic constructor •() → self::Animal2
+    ;
+}
+@val::valueClass
+class Cat2 extends self::Animal2 {
+  synthetic constructor •() → self::Cat2
+    ;
+}
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.strong.expect

@@ -6,9 +6,16 @@ library /*isNonNullableByDefault*/;
 //   int numberOfLegs;
 //       ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value_error.dart:15:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -20,9 +27,40 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
+class Animal2 extends core::Object {
+  final field core::int numberOfLegs = null;
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+}
+class Cat2 extends self::Animal2 {
+  synthetic constructor •() → self::Cat2
+    : super self::Animal2::•()
+    ;
+}
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.strong.transformed.expect

@@ -6,9 +6,16 @@ library /*isNonNullableByDefault*/;
 //   int numberOfLegs;
 //       ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value_error.dart:15:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -20,9 +27,40 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
+class Animal2 extends core::Object {
+  final field core::int numberOfLegs = null;
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+}
+class Cat2 extends self::Animal2 {
+  synthetic constructor •() → self::Cat2
+    : super self::Animal2::•()
+    ;
+}
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 class Animal {
   int numberOfLegs;
@@ -7,4 +7,11 @@ class Animal {
 @valueClass
 class Cat extends Animal {}
 
+class Animal2 {
+  final int numberOfLegs;
+}
+
+@valueClass
+class Cat2 extends Animal2 {}
+
 main() {}

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.textual_outline_modelled.expect

@@ -1,9 +1,17 @@
+import 'value_class_support_lib.dart';
+
 class Animal {
   int numberOfLegs;
 }
 
+class Animal2 {
+  final int numberOfLegs;
+}
+
 @valueClass
 class Cat extends Animal {}
 
-const String valueClass = "valueClass";
+@valueClass
+class Cat2 extends Animal2 {}
+
 main() {}

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.weak.expect

@@ -6,9 +6,16 @@ library /*isNonNullableByDefault*/;
 //   int numberOfLegs;
 //       ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value_error.dart:15:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -20,9 +27,40 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
+class Animal2 extends core::Object {
+  final field core::int numberOfLegs = null;
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+}
+class Cat2 extends self::Animal2 {
+  synthetic constructor •() → self::Cat2
+    : super self::Animal2::•()
+    ;
+}
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_extends_non_value_error.dart.weak.transformed.expect

@@ -6,9 +6,16 @@ library /*isNonNullableByDefault*/;
 //   int numberOfLegs;
 //       ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_extends_non_value_error.dart:15:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -20,9 +27,40 @@ class Cat extends self::Animal {
     : super self::Animal::•()
     ;
 }
-static const field core::String valueClass = #C1;
+class Animal2 extends core::Object {
+  final field core::int numberOfLegs = null;
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+}
+class Cat2 extends self::Animal2 {
+  synthetic constructor •() → self::Cat2
+    : super self::Animal2::•()
+    ;
+}
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_implements_non_value.dart

@@ -2,7 +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.
 
-const String valueClass = "valueClass";
+import '../nnbd_mixed/nnbd_opt_out_language_version.dart';
+import 'value_class_support_lib.dart';
 
 class Animal {
   final int numberOfLegs;
@@ -11,6 +12,42 @@ class Animal {
 @valueClass
 class Cat implements Animal {
   final int numberOfLegs;
+  final int numberOfWhiskers;
 }
 
-main() {}
+abstract class Animal2 {
+  int get numberOfLegs;
+}
+
+@valueClass
+class Cat2 implements Animal2 {
+  final int numberOfLegs;
+  final int numberOfWhiskers;
+}
+
+
+main() {
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+
+  expect(true, firstCat == secondCat);
+  expect(false, firstCat == thirdCat);
+
+  expect(true, firstCat.hashCode == secondCat.hashCode);
+  expect(false, firstCat.hashCode == thirdCat.hashCode);
+
+  Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+  Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+  Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+
+  expect(true, firstCat2 == secondCat2);
+  expect(false, firstCat2 == thirdCat2);
+
+  expect(true, firstCat2.hashCode == secondCat2.hashCode);
+  expect(false, firstCat2.hashCode == thirdCat2.hashCode);
+}
+
+expect(Object? expected, Object? actual) {
+  if (expected != actual) throw 'Expected=$expected, actual=$actual';
+}

pkg/front_end/testcases/value_class/value_implements_non_value.dart.outline.expect

@@ -1,18 +1,82 @@
 library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
+import "value_class_support_lib.dart" as val;
+
+import "org-dartlang-testcase-sdk:///pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart";
+import "org-dartlang-testcase:///value_class_support_lib.dart";
 
 class Animal extends core::Object {
   final field core::int numberOfLegs;
   synthetic constructor •() → self::Animal
     ;
 }
-@self::valueClass
+@val::valueClass
 class Cat extends core::Object implements self::Animal {
   final field core::int numberOfLegs;
+  final field core::int numberOfWhiskers;
   synthetic constructor •() → self::Cat
     ;
 }
-static const field core::String valueClass = "valueClass";
+abstract class Animal2 extends core::Object {
+  synthetic constructor •() → self::Animal2
+    ;
+  abstract get numberOfLegs() → core::int;
+}
+@val::valueClass
+class Cat2 extends core::Object implements self::Animal2 {
+  final field core::int numberOfLegs;
+  final field core::int numberOfWhiskers;
+  synthetic constructor •() → self::Cat2
+    ;
+}
 static method main() → dynamic
   ;
+static method expect(core::Object? expected, core::Object? actual) → dynamic
+  ;
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:1:1: Error: A library can't opt out of null safety by default, when using sound null safety.
+// // @dart=2.4
+// ^^^^^^^^^^^^
+//
+import self as self2;
+import "dart:core" as core;
+
+class late extends core::Object {
+  synthetic constructor •() → self2::late
+    ;
+  get g() → core::int
+    ;
+}
+class required extends core::Object {
+  synthetic constructor •() → self2::required
+    ;
+  get g() → core::int
+    ;
+}
+class C extends core::Object {
+  field self2::late l;
+  field self2::required r;
+  synthetic constructor •() → self2::C
+    ;
+}
+static method main() → dynamic
+  ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/value_implements_non_value.dart.strong.expect

@@ -2,19 +2,79 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:8:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                          ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:24:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:25:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase-sdk:///pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart";
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -23,12 +83,139 @@ class Animal extends core::Object {
 }
 class Cat extends core::Object implements self::Animal {
   final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, super core::Object::•()
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
+    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
     ;
 }
+abstract class Animal2 extends core::Object {
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+  abstract get numberOfLegs() → core::int;
+}
+class Cat2 extends core::Object implements self::Animal2 {
+  final field core::int numberOfLegs = null;
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat2
+    : self::Cat2::numberOfLegs = numberOfLegs, self::Cat2::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
+    ;
+}
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+  self::Cat2 firstCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                        ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat2;
+  self::Cat2 secondCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                         ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat2;
+  self::Cat2 thirdCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+                        ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat2;
+  self::expect(true, firstCat2.{core::Object::==}(secondCat2));
+  self::expect(false, firstCat2.{core::Object::==}(thirdCat2));
+  self::expect(true, firstCat2.{core::Object::hashCode}.{core::num::==}(secondCat2.{core::Object::hashCode}));
+  self::expect(false, firstCat2.{core::Object::hashCode}.{core::num::==}(thirdCat2.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:1:1: Error: A library can't opt out of null safety by default, when using sound null safety.
+// // @dart=2.4
+// ^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:3:7: Error: Can't use 'late' as a name here.
+// class late {
+//       ^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:7:7: Error: Can't use 'required' as a name here.
+// class required {
+//       ^^^^^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:12:8: Error: Variables must be declared using the keywords 'const', 'final', 'var' or a type name.
+// Try adding the name of the type of the variable or the keyword 'var'.
+//   late l = late();
+//        ^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:13:3: Error: Can't have modifier 'required' here.
+// Try removing 'required'.
+//   required r = required();
+//   ^^^^^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:13:12: Error: Variables must be declared using the keywords 'const', 'final', 'var' or a type name.
+// Try adding the name of the type of the variable or the keyword 'var'.
+//   required r = required();
+//            ^
+//
+import self as self2;
+import "dart:core" as core;
+
+class late extends core::Object {
+  synthetic constructor •() → self2::late
+    : super core::Object::•()
+    ;
+  get g() → core::int
+    return 1;
+}
+class required extends core::Object {
+  synthetic constructor •() → self2::required
+    : super core::Object::•()
+    ;
+  get g() → core::int
+    return 2;
+}
+class C extends core::Object {
+  field self2::late l = new self2::late::•();
+  field self2::required r = new self2::required::•();
+  synthetic constructor •() → self2::C
+    : super core::Object::•()
+    ;
+}
+static method main() → dynamic {
+  if(!new self2::C::•().{self2::C::l}.{self2::late::g}.{core::num::==}(1))
+    throw "Expected 1";
+  if(!new self2::C::•().{self2::C::r}.{self2::required::g}.{core::num::==}(2))
+    throw "Expected 2";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self3;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self3::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C1;
-static method main() → dynamic {}
 
 constants  {
   #C1 = "valueClass"

pkg/front_end/testcases/value_class/value_implements_non_value.dart.strong.transformed.expect

@@ -2,19 +2,79 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:8:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                          ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:24:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:25:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase-sdk:///pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart";
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -23,12 +83,139 @@ class Animal extends core::Object {
 }
 class Cat extends core::Object implements self::Animal {
   final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, super core::Object::•()
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
+    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
     ;
 }
+abstract class Animal2 extends core::Object {
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+  abstract get numberOfLegs() → core::int;
+}
+class Cat2 extends core::Object implements self::Animal2 {
+  final field core::int numberOfLegs = null;
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat2
+    : self::Cat2::numberOfLegs = numberOfLegs, self::Cat2::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
+    ;
+}
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^";
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^";
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^";
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+  self::Cat2 firstCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                        ^^^^^^^^^^^^";
+  self::Cat2 secondCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                         ^^^^^^^^^^^^";
+  self::Cat2 thirdCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+                        ^^^^^^^^^^^^";
+  self::expect(true, firstCat2.{core::Object::==}(secondCat2));
+  self::expect(false, firstCat2.{core::Object::==}(thirdCat2));
+  self::expect(true, firstCat2.{core::Object::hashCode}.{core::num::==}(secondCat2.{core::Object::hashCode}));
+  self::expect(false, firstCat2.{core::Object::hashCode}.{core::num::==}(thirdCat2.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library /*isNonNullableByDefault*/;
+//
+// Problems in library:
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:1:1: Error: A library can't opt out of null safety by default, when using sound null safety.
+// // @dart=2.4
+// ^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:3:7: Error: Can't use 'late' as a name here.
+// class late {
+//       ^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:7:7: Error: Can't use 'required' as a name here.
+// class required {
+//       ^^^^^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:12:8: Error: Variables must be declared using the keywords 'const', 'final', 'var' or a type name.
+// Try adding the name of the type of the variable or the keyword 'var'.
+//   late l = late();
+//        ^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:13:3: Error: Can't have modifier 'required' here.
+// Try removing 'required'.
+//   required r = required();
+//   ^^^^^^^^
+//
+// pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart:13:12: Error: Variables must be declared using the keywords 'const', 'final', 'var' or a type name.
+// Try adding the name of the type of the variable or the keyword 'var'.
+//   required r = required();
+//            ^
+//
+import self as self2;
+import "dart:core" as core;
+
+class late extends core::Object {
+  synthetic constructor •() → self2::late
+    : super core::Object::•()
+    ;
+  get g() → core::int
+    return 1;
+}
+class required extends core::Object {
+  synthetic constructor •() → self2::required
+    : super core::Object::•()
+    ;
+  get g() → core::int
+    return 2;
+}
+class C extends core::Object {
+  field self2::late l = new self2::late::•();
+  field self2::required r = new self2::required::•();
+  synthetic constructor •() → self2::C
+    : super core::Object::•()
+    ;
+}
+static method main() → dynamic {
+  if(!new self2::C::•().{self2::C::l}.{self2::late::g}.{core::num::==}(1))
+    throw "Expected 1";
+  if(!new self2::C::•().{self2::C::r}.{self2::required::g}.{core::num::==}(2))
+    throw "Expected 2";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self3;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self3::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C1;
-static method main() → dynamic {}
 
 constants  {
   #C1 = "valueClass"

pkg/front_end/testcases/value_class/value_implements_non_value.dart.textual_outline.expect

@@ -1,4 +1,5 @@
-const String valueClass = "valueClass";
+import '../nnbd_mixed/nnbd_opt_out_language_version.dart';
+import 'value_class_support_lib.dart';
 
 class Animal {
   final int numberOfLegs;
@@ -7,6 +8,18 @@ class Animal {
 @valueClass
 class Cat implements Animal {
   final int numberOfLegs;
+  final int numberOfWhiskers;
+}
+
+abstract class Animal2 {
+  int get numberOfLegs;
+}
+
+@valueClass
+class Cat2 implements Animal2 {
+  final int numberOfLegs;
+  final int numberOfWhiskers;
 }
 
 main() {}
+expect(Object? expected, Object? actual) {}

pkg/front_end/testcases/value_class/value_implements_non_value.dart.textual_outline_modelled.expect

@@ -1,3 +1,10 @@
+import '../nnbd_mixed/nnbd_opt_out_language_version.dart';
+import 'value_class_support_lib.dart';
+
+abstract class Animal2 {
+  int get numberOfLegs;
+}
+
 class Animal {
   final int numberOfLegs;
 }
@@ -5,7 +12,14 @@ class Animal {
 @valueClass
 class Cat implements Animal {
   final int numberOfLegs;
+  final int numberOfWhiskers;
 }
 
-const String valueClass = "valueClass";
+@valueClass
+class Cat2 implements Animal2 {
+  final int numberOfLegs;
+  final int numberOfWhiskers;
+}
+
+expect(Object? expected, Object? actual) {}
 main() {}

pkg/front_end/testcases/value_class/value_implements_non_value.dart.weak.expect

@@ -2,19 +2,79 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:8:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                          ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:24:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:25:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase-sdk:///pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart";
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -23,12 +83,139 @@ class Animal extends core::Object {
 }
 class Cat extends core::Object implements self::Animal {
   final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, super core::Object::•()
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
+    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
     ;
 }
+abstract class Animal2 extends core::Object {
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+  abstract get numberOfLegs() → core::int;
+}
+class Cat2 extends core::Object implements self::Animal2 {
+  final field core::int numberOfLegs = null;
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat2
+    : self::Cat2::numberOfLegs = numberOfLegs, self::Cat2::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
+    ;
+}
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat;
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+  self::Cat2 firstCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                        ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat2;
+  self::Cat2 secondCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                         ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat2;
+  self::Cat2 thirdCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+                        ^^^^^^^^^^^^" as{TypeError,ForDynamic,ForNonNullableByDefault} self::Cat2;
+  self::expect(true, firstCat2.{core::Object::==}(secondCat2));
+  self::expect(false, firstCat2.{core::Object::==}(thirdCat2));
+  self::expect(true, firstCat2.{core::Object::hashCode}.{core::num::==}(secondCat2.{core::Object::hashCode}));
+  self::expect(false, firstCat2.{core::Object::hashCode}.{core::num::==}(thirdCat2.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+class late extends core::Object {
+  synthetic constructor •() → self2::late*
+    : super core::Object::•()
+    ;
+  get g() → core::int*
+    return 1;
+  abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
+  abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
+  abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
+  abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue
+  abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse
+  abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::==
+  abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode
+  abstract member-signature method toString() → core::String*; -> core::Object::toString
+  abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
+  abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
+}
+class required extends core::Object {
+  synthetic constructor •() → self2::required*
+    : super core::Object::•()
+    ;
+  get g() → core::int*
+    return 2;
+  abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
+  abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
+  abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
+  abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue
+  abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse
+  abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::==
+  abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode
+  abstract member-signature method toString() → core::String*; -> core::Object::toString
+  abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
+  abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
+}
+class C extends core::Object {
+  field self2::late* l = new self2::late::•();
+  field self2::required* r = new self2::required::•();
+  synthetic constructor •() → self2::C*
+    : super core::Object::•()
+    ;
+  abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
+  abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
+  abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
+  abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue
+  abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse
+  abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::==
+  abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode
+  abstract member-signature method toString() → core::String*; -> core::Object::toString
+  abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
+  abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
+}
+static method main() → dynamic {
+  if(!new self2::C::•().{self2::C::l}.{self2::late::g}.{core::num::==}(1))
+    throw "Expected 1";
+  if(!new self2::C::•().{self2::C::r}.{self2::required::g}.{core::num::==}(2))
+    throw "Expected 2";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self3;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self3::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C1;
-static method main() → dynamic {}
 
 constants  {
   #C1 = "valueClass"

pkg/front_end/testcases/value_class/value_implements_non_value.dart.weak.transformed.expect

@@ -2,19 +2,79 @@ library /*isNonNullableByDefault*/;
 //
 // Problems in library:
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:8:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+//                       ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+//                      ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:7: Context: The class 'Cat' has a constructor that takes no arguments.
+// class Cat implements Animal {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+//                          ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+//   Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+//                         ^^^^^^^^^^^^
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:23:7: Context: The class 'Cat2' has a constructor that takes no arguments.
+// class Cat2 implements Animal2 {
+//       ^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:9:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
-// pkg/front_end/testcases/value_class/value_implements_non_value.dart:13:13: Error: Final field 'numberOfLegs' is not initialized.
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:14:13: Error: Final field 'numberOfLegs' is not initialized.
 // Try to initialize the field in the declaration or in every constructor.
 //   final int numberOfLegs;
 //             ^^^^^^^^^^^^
 //
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:15:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:24:13: Error: Final field 'numberOfLegs' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfLegs;
+//             ^^^^^^^^^^^^
+//
+// pkg/front_end/testcases/value_class/value_implements_non_value.dart:25:13: Error: Final field 'numberOfWhiskers' is not initialized.
+// Try to initialize the field in the declaration or in every constructor.
+//   final int numberOfWhiskers;
+//             ^^^^^^^^^^^^^^^^
+//
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase-sdk:///pkg/front_end/testcases/nnbd_mixed/nnbd_opt_out_language_version.dart";
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class Animal extends core::Object {
   final field core::int numberOfLegs = null;
   synthetic constructor •() → self::Animal
@@ -23,12 +83,139 @@ class Animal extends core::Object {
 }
 class Cat extends core::Object implements self::Animal {
   final field core::int numberOfLegs = null;
-  synthetic constructor •({required core::int numberOfLegs}) → self::Cat
-    : self::Cat::numberOfLegs = numberOfLegs, super core::Object::•()
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat
+    : self::Cat::numberOfLegs = numberOfLegs, self::Cat::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
     ;
 }
+abstract class Animal2 extends core::Object {
+  synthetic constructor •() → self::Animal2
+    : super core::Object::•()
+    ;
+  abstract get numberOfLegs() → core::int;
+}
+class Cat2 extends core::Object implements self::Animal2 {
+  final field core::int numberOfLegs = null;
+  final field core::int numberOfWhiskers = null;
+  synthetic constructor •({required core::int numberOfLegs, required core::int numberOfWhiskers}) → self::Cat2
+    : self::Cat2::numberOfLegs = numberOfLegs, self::Cat2::numberOfWhiskers = numberOfWhiskers, super core::Object::•()
+    ;
+}
+static method main() → dynamic {
+  self::Cat firstCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:30:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat firstCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                     ^^^^^^^^^^^^";
+  self::Cat secondCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:31:23: Error: No named parameter with the name 'numberOfLegs'.
+  Cat secondCat = Cat(numberOfLegs: 4, numberOfWhiskers: 10);
+                      ^^^^^^^^^^^^";
+  self::Cat thirdCat = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:32:22: Error: No named parameter with the name 'numberOfLegs'.
+  Cat thirdCat = Cat(numberOfLegs: 4, numberOfWhiskers: 0);
+                     ^^^^^^^^^^^^";
+  self::expect(true, firstCat.{core::Object::==}(secondCat));
+  self::expect(false, firstCat.{core::Object::==}(thirdCat));
+  self::expect(true, firstCat.{core::Object::hashCode}.{core::num::==}(secondCat.{core::Object::hashCode}));
+  self::expect(false, firstCat.{core::Object::hashCode}.{core::num::==}(thirdCat.{core::Object::hashCode}));
+  self::Cat2 firstCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:40:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 firstCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                        ^^^^^^^^^^^^";
+  self::Cat2 secondCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:41:26: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 secondCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 10);
+                         ^^^^^^^^^^^^";
+  self::Cat2 thirdCat2 = invalid-expression "pkg/front_end/testcases/value_class/value_implements_non_value.dart:42:25: Error: No named parameter with the name 'numberOfLegs'.
+  Cat2 thirdCat2 = Cat2(numberOfLegs: 4, numberOfWhiskers: 0);
+                        ^^^^^^^^^^^^";
+  self::expect(true, firstCat2.{core::Object::==}(secondCat2));
+  self::expect(false, firstCat2.{core::Object::==}(thirdCat2));
+  self::expect(true, firstCat2.{core::Object::hashCode}.{core::num::==}(secondCat2.{core::Object::hashCode}));
+  self::expect(false, firstCat2.{core::Object::hashCode}.{core::num::==}(thirdCat2.{core::Object::hashCode}));
+}
+static method expect(core::Object? expected, core::Object? actual) → dynamic {
+  if(!expected.{core::Object::==}(actual))
+    throw "Expected=${expected}, actual=${actual}";
+}
+
+library;
+import self as self2;
+import "dart:core" as core;
+
+class late extends core::Object {
+  synthetic constructor •() → self2::late*
+    : super core::Object::•()
+    ;
+  get g() → core::int*
+    return 1;
+  abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
+  abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
+  abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
+  abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue
+  abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse
+  abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::==
+  abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode
+  abstract member-signature method toString() → core::String*; -> core::Object::toString
+  abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
+  abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
+}
+class required extends core::Object {
+  synthetic constructor •() → self2::required*
+    : super core::Object::•()
+    ;
+  get g() → core::int*
+    return 2;
+  abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
+  abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
+  abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
+  abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue
+  abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse
+  abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::==
+  abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode
+  abstract member-signature method toString() → core::String*; -> core::Object::toString
+  abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
+  abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
+}
+class C extends core::Object {
+  field self2::late* l = new self2::late::•();
+  field self2::required* r = new self2::required::•();
+  synthetic constructor •() → self2::C*
+    : super core::Object::•()
+    ;
+  abstract member-signature get _identityHashCode() → core::int*; -> core::Object::_identityHashCode
+  abstract member-signature method _instanceOf(dynamic instantiatorTypeArguments, dynamic functionTypeArguments, dynamic type) → core::bool*; -> core::Object::_instanceOf
+  abstract member-signature method _simpleInstanceOf(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOf
+  abstract member-signature method _simpleInstanceOfTrue(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfTrue
+  abstract member-signature method _simpleInstanceOfFalse(dynamic type) → core::bool*; -> core::Object::_simpleInstanceOfFalse
+  abstract member-signature operator ==(dynamic other) → core::bool*; -> core::Object::==
+  abstract member-signature get hashCode() → core::int*; -> core::Object::hashCode
+  abstract member-signature method toString() → core::String*; -> core::Object::toString
+  abstract member-signature method noSuchMethod(core::Invocation* invocation) → dynamic; -> core::Object::noSuchMethod
+  abstract member-signature get runtimeType() → core::Type*; -> core::Object::runtimeType
+}
+static method main() → dynamic {
+  if(!new self2::C::•().{self2::C::l}.{self2::late::g}.{core::num::==}(1))
+    throw "Expected 1";
+  if(!new self2::C::•().{self2::C::r}.{self2::required::g}.{core::num::==}(2))
+    throw "Expected 2";
+}
+
+library /*isNonNullableByDefault*/;
+import self as self3;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self3::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
 static const field core::String valueClass = #C1;
-static method main() → dynamic {}
 
 constants  {
   #C1 = "valueClass"

pkg/front_end/testcases/value_class/value_mixin_error.dart

@@ -2,7 +2,7 @@
 // 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.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class A {}

pkg/front_end/testcases/value_class/value_mixin_error.dart.outline.expect

@@ -1,8 +1,11 @@
 library /*isNonNullableByDefault*/;
 import self as self;
+import "value_class_support_lib.dart" as val;
 import "dart:core" as core;
 
-@self::valueClass
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
+@val::valueClass
 class A extends core::Object {
   synthetic constructor •() → self::A
     ;
@@ -29,6 +32,19 @@ class D extends self::_D&A&B {
   synthetic constructor •() → self::D
     ;
 }
-static const field core::String valueClass = "valueClass";
 static method main() → dynamic
   ;
+
+library /*isNonNullableByDefault*/;
+import self as val;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → val::JenkinsSmiHash
+    ;
+  static method combine(core::int hash, core::int value) → core::int
+    ;
+  static method finish(core::int hash) → core::int
+    ;
+}
+static const field core::String valueClass = "valueClass";

pkg/front_end/testcases/value_class/value_mixin_error.dart.strong.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class D extends self::_D&A&B {
     : super self::_D&A&B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_mixin_error.dart.strong.transformed.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class D extends self::_D&A&B {
     : super self::_D&A&B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_mixin_error.dart.textual_outline.expect

@@ -1,4 +1,4 @@
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class A {}

pkg/front_end/testcases/value_class/value_mixin_error.dart.textual_outline_modelled.expect

@@ -1,3 +1,5 @@
+import 'value_class_support_lib.dart';
+
 @valueClass
 class A {}
 
@@ -7,5 +9,4 @@ class C extends B with A {}
 
 class D extends A with B {}
 
-const String valueClass = "valueClass";
 main() {}

pkg/front_end/testcases/value_class/value_mixin_error.dart.weak.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class D extends self::_D&A&B {
     : super self::_D&A&B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/value_class/value_mixin_error.dart.weak.transformed.expect

@@ -2,6 +2,8 @@ library /*isNonNullableByDefault*/;
 import self as self;
 import "dart:core" as core;
 
+import "org-dartlang-testcase:///value_class_support_lib.dart";
+
 class A extends core::Object {
   synthetic constructor •() → self::A
     : super core::Object::•()
@@ -32,9 +34,29 @@ class D extends self::_D&A&B {
     : super self::_D&A&B::•()
     ;
 }
-static const field core::String valueClass = #C1;
 static method main() → dynamic {}
 
+library /*isNonNullableByDefault*/;
+import self as self2;
+import "dart:core" as core;
+
+class JenkinsSmiHash extends core::Object {
+  synthetic constructor •() → self2::JenkinsSmiHash
+    : super core::Object::•()
+    ;
+  static method combine(core::int hash, core::int value) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(value));
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(524287.{core::int::&}(hash).{core::int::<<}(10)));
+    return hash.{core::int::^}(hash.{core::int::>>}(6));
+  }
+  static method finish(core::int hash) → core::int {
+    hash = 536870911.{core::int::&}(hash.{core::num::+}(67108863.{core::int::&}(hash).{core::int::<<}(3)));
+    hash = hash.{core::int::^}(hash.{core::int::>>}(11));
+    return 536870911.{core::int::&}(hash.{core::num::+}(16383.{core::int::&}(hash).{core::int::<<}(15)));
+  }
+}
+static const field core::String valueClass = #C1;
+
 constants  {
   #C1 = "valueClass"
 }

pkg/front_end/testcases/weak.status

@@ -73,5 +73,5 @@ nnbd_mixed/messages_with_types_opt_in: TypeCheckError
 nnbd_mixed/messages_with_types_opt_out: TypeCheckError
 nnbd_mixed/never_opt_out: TypeCheckError
 value_class/simple: RuntimeError # Expected
-value_class/super_type: RuntimeError # Expected
-
+value_class/value_extends_non_value: RuntimeError # Expected
+value_class/value_implements_non_value: RuntimeError # Expected

tests/language/value_class/creates_constructor_test.dart

@@ -4,7 +4,7 @@
 
 // A value class will automatically create an empty constructor if there is none yet
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

tests/language/value_class/creates_equals_test.dart

@@ -5,11 +5,10 @@
 // Equals operator == by value should be implicitly created
 
 import 'package:expect/expect.dart';
+import 'value_class_support_lib.dart';
 
 // A value class will automatically create an == operator if there is none yet
 
-const String valueClass = "valueClass";
-
 @valueClass
 class Animal {
   final int numberOfLegs;

tests/language/value_class/has_non_final_field_error_test.dart

@@ -4,7 +4,7 @@
 
 // It is a compile-time error if a value class has a non-final instance variable.
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {

tests/language/value_class/inherits_non_value_class_error_test.dart

@@ -4,7 +4,7 @@
 
 // Value classes are always leaves in the tree of types
 
-const String valueClass = "valueClass";
+import 'value_class_support_lib.dart';
 
 @valueClass
 class Animal {}

tests/language/value_class/value_class_support_lib.dart

@@ -0,0 +1,21 @@
+// Copyright (c) 2020, 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 file.
+
+// TODO(jlcontreras): this is a temp file for the valueClass experiment
+const valueClass = "valueClass";
+
+/// This code is from the dart.math sdk/lib/math/jenkins_smi_hash.dart
+class JenkinsSmiHash {
+  static int combine(int hash, int value) {
+    hash = 0x1fffffff & (hash + value);
+    hash = 0x1fffffff & (hash + ((0x0007ffff & hash) << 10));
+    return hash ^ (hash >> 6);
+  }
+
+  static int finish(int hash) {
+    hash = 0x1fffffff & (hash + ((0x03ffffff & hash) << 3));
+    hash = hash ^ (hash >> 11);
+    return 0x1fffffff & (hash + ((0x00003fff & hash) << 15));
+  }
+}