Initial isolate reload support

runtime/vm/isolate_reload_test.cc

+// Copyright (c) 2016, 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.
+
+#include "include/dart_api.h"
+#include "include/dart_tools_api.h"
+#include "platform/assert.h"
+#include "vm/globals.h"
+#include "vm/isolate.h"
+#include "vm/lockers.h"
+#include "vm/thread_barrier.h"
+#include "vm/thread_pool.h"
+#include "vm/unit_test.h"
+
+namespace dart {
+
+#ifndef PRODUCT
+
+// TODO(johnmccutchan):
+// - Tests involving generics.
+
+int64_t SimpleInvoke(Dart_Handle lib, const char* method) {
+  Dart_Handle result = Dart_Invoke(lib, NewString(method), 0, NULL);
+  EXPECT_VALID(result);
+  EXPECT(Dart_IsInteger(result));
+  int64_t integer_result = 0;
+  result = Dart_IntegerToInt64(result, &integer_result);
+  EXPECT_VALID(result);
+  return integer_result;
+}
+
+
+const char* SimpleInvokeStr(Dart_Handle lib, const char* method) {
+  Dart_Handle result = Dart_Invoke(lib, NewString(method), 0, NULL);
+  const char* result_str = NULL;
+  EXPECT(Dart_IsString(result));
+  EXPECT_VALID(Dart_StringToCString(result, &result_str));
+  return result_str;
+}
+
+
+Dart_Handle SimpleInvokeError(Dart_Handle lib, const char* method) {
+  Dart_Handle result = Dart_Invoke(lib, NewString(method), 0, NULL);
+  EXPECT(Dart_IsError(result));
+  return result;
+}
+
+
+TEST_CASE(IsolateReload_FunctionReplacement) {
+  const char* kScript =
+      "main() {\n"
+      "  return 4;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "var _unused;"
+      "main() {\n"
+      "  return 10;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(10, SimpleInvoke(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_BadClass) {
+  const char* kScript =
+      "class Foo {\n"
+      "  final a;\n"
+      "  Foo(this.a);\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo(5);\n"
+      "  return 4;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "var _unused;"
+      "class Foo {\n"
+      "  final a kjsdf ksjdf ;\n"
+      "  Foo(this.a);\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo(5);\n"
+      "  return 10;\n"
+      "}\n";
+
+  Dart_Handle result = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(result, "unexpected token");
+
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_StaticValuePreserved) {
+  const char* kScript =
+      "init() => 'old value';\n"
+      "var value = init();\n"
+      "main() {\n"
+      "  return 'init()=${init()},value=${value}';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("init()=old value,value=old value",
+               SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "var _unused;"
+      "init() => 'new value';\n"
+      "var value = init();\n"
+      "main() {\n"
+      "  return 'init()=${init()},value=${value}';\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("init()=new value,value=old value",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_SavedClosure) {
+  // Create a closure in main which only exists in the original source.
+  const char* kScript =
+      "magic() {\n"
+      "  var x = 'ante';\n"
+      "  return x + 'diluvian';\n"
+      "}\n"
+      "var closure;\n"
+      "main() {\n"
+      "  closure = () { return magic().toString() + '!'; };\n"
+      "  return closure();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("antediluvian!", SimpleInvokeStr(lib, "main"));
+
+  // Remove the original closure from the source code.  The closure is
+  // able to be recompiled because its source is preserved in a
+  // special patch class.
+  const char* kReloadScript =
+      "magic() {\n"
+      "  return 'postapocalyptic';\n"
+      "}\n"
+      "var closure;\n"
+      "main() {\n"
+      "  return closure();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("postapocalyptic!", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_TopLevelFieldAdded) {
+  const char* kScript =
+      "var value1 = 10;\n"
+      "main() {\n"
+      "  return 'value1=${value1}';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("value1=10", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "var value1 = 10;\n"
+      "var value2 = 20;\n"
+      "main() {\n"
+      "  return 'value1=${value1},value2=${value2}';\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("value1=10,value2=20",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_ClassFieldAdded) {
+  const char* kScript =
+      "class Foo {\n"
+      "  var x;\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo();\n"
+      "  return 44;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(44, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "class Foo {\n"
+      "  var x;\n"
+      "  var y;\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo();\n"
+      "  return 44;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(lib, "Number of instance fields changed");
+}
+
+
+TEST_CASE(IsolateReload_ClassFieldRemoved) {
+  const char* kScript =
+      "class Foo {\n"
+      "  var x;\n"
+      "  var y;\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo();\n"
+      "  return 44;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(44, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "class Foo {\n"
+      "  var x;\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo();\n"
+      "  return 44;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(lib, "Number of instance fields changed");
+}
+
+
+TEST_CASE(IsolateReload_ClassAdded) {
+  const char* kScript =
+      "main() {\n"
+      "  return 'hello';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("hello", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "var _unused;"
+      "class A {\n"
+      "  toString() => 'hello from A';\n"
+      "}\n"
+      "main() {\n"
+      "  return new A().toString();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("hello from A", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_LibraryImportAdded) {
+  const char* kScript =
+      "main() {\n"
+      "  return max(3, 4);\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_ERROR(SimpleInvokeError(lib, "main"), "max");;
+
+  const char* kReloadScript =
+      "import 'dart:math';\n"
+      "main() {\n"
+      "  return max(3, 4);\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_LibraryImportRemoved) {
+  const char* kScript =
+      "import 'dart:math';\n"
+      "main() {\n"
+      "  return max(3, 4);\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "main() {\n"
+      "  return max(3, 4);\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_ERROR(SimpleInvokeError(lib, "main"), "max");;
+}
+
+
+TEST_CASE(IsolateReload_LibraryDebuggable) {
+  const char* kScript =
+      "main() {\n"
+      "  return 1;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  // The library is by default debuggable.  Make it not debuggable.
+  intptr_t lib_id = -1;
+  bool debuggable = false;
+  EXPECT_VALID(Dart_LibraryId(lib, &lib_id));
+  EXPECT_VALID(Dart_GetLibraryDebuggable(lib_id, &debuggable));
+  EXPECT_EQ(true, debuggable);
+  EXPECT_VALID(Dart_SetLibraryDebuggable(lib_id, false));
+  EXPECT_VALID(Dart_GetLibraryDebuggable(lib_id, &debuggable));
+  EXPECT_EQ(false, debuggable);
+
+  EXPECT_EQ(1, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "main() {\n"
+      "  return 2;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(2, SimpleInvoke(lib, "main"));
+
+  // Library debuggability is preserved.
+  intptr_t new_lib_id = -1;
+  EXPECT_VALID(Dart_LibraryId(lib, &new_lib_id));
+  EXPECT_VALID(Dart_GetLibraryDebuggable(new_lib_id, &debuggable));
+  EXPECT_EQ(false, debuggable);
+}
+
+
+TEST_CASE(IsolateReload_ImplicitConstructorChanged) {
+  // Note that we are checking that the value 20 gets cleared from the
+  // compile-time constants cache.  To make this test work, "20" and
+  // "10" need to be at the same token position.
+  const char* kScript =
+      "class A {\n"
+      "  int field = 20;\n"
+      "}\n"
+      "var savedA = new A();\n"
+      "main() {\n"
+      "  var newA = new A();\n"
+      "  return 'saved:${savedA.field} new:${newA.field}';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("saved:20 new:20", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "class A {\n"
+      "  int field = 10;\n"
+      "}\n"
+      "var savedA = new A();\n"
+      "main() {\n"
+      "  var newA = new A();\n"
+      "  return 'saved:${savedA.field} new:${newA.field}';\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("saved:20 new:10", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_ConstructorChanged) {
+  const char* kScript =
+      "class A {\n"
+      "  int field;\n"
+      "  A() { field = 20; }\n"
+      "}\n"
+      "var savedA = new A();\n"
+      "main() {\n"
+      "  var newA = new A();\n"
+      "  return 'saved:${savedA.field} new:${newA.field}';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("saved:20 new:20", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "var _unused;"
+      "class A {\n"
+      "  int field;\n"
+      "  A() { field = 10; }\n"
+      "}\n"
+      "var savedA = new A();\n"
+      "main() {\n"
+      "  var newA = new A();\n"
+      "  return 'saved:${savedA.field} new:${newA.field}';\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("saved:20 new:10", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_SuperClassChanged) {
+  const char* kScript =
+      "class A {\n"
+      "}\n"
+      "class B extends A {\n"
+      "}\n"
+      "var list = [ new A(), new B() ];\n"
+      "main() {\n"
+      "  return (list.map((x) => '${x is A}/${x is B}')).toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("(true/false, true/true)", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "var _unused;"
+      "class B{\n"
+      "}\n"
+      "class A extends B {\n"
+      "}\n"
+      "var list = [ new A(), new B() ];\n"
+      "main() {\n"
+      "  return (list.map((x) => '${x is A}/${x is B}')).toString();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("(true/true, false/true)", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_Generics) {
+  // Reload a program with generics without changing the source.  We
+  // do this to produce duplication TypeArguments and make sure that
+  // the system doesn't die.
+  const char* kScript =
+      "class A {\n"
+      "}\n"
+      "class B<T extends A> {\n"
+      "}\n"
+      "main() {\n"
+      "  return new B<A>().toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Instance of 'B<A>'", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "class A {\n"
+      "}\n"
+      "class B<T extends A> {\n"
+      "}\n"
+      "main() {\n"
+      "  return new B<A>().toString();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Instance of 'B<A>'", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_MixinChanged) {
+  const char* kScript =
+      "class Mixin1 {\n"
+      "  var field = 'mixin1';\n"
+      "  func() => 'mixin1';\n"
+      "}\n"
+      "class B extends Object with Mixin1 {\n"
+      "}\n"
+      "var saved = new B();\n"
+      "main() {\n"
+      "  return 'saved:field=${saved.field},func=${saved.func()}';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("saved:field=mixin1,func=mixin1",
+               SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "class Mixin2 {\n"
+      "  var field = 'mixin2';\n"
+      "  func() => 'mixin2';\n"
+      "}\n"
+      "class B extends Object with Mixin2 {\n"
+      "}\n"
+      "var saved = new B();\n"
+      "main() {\n"
+      "  var newer = new B();\n"
+      "  return 'saved:field=${saved.field},func=${saved.func()} '\n"
+      "         'newer:field=${newer.field},func=${newer.func()}';\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  // The saved instance of B retains its old field value from mixin1,
+  // but it gets the new implementation of func from mixin2.
+  EXPECT_STREQ("saved:field=mixin1,func=mixin2 "
+               "newer:field=mixin2,func=mixin2",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_ComplexInheritanceChange) {
+  const char* kScript =
+      "class A {\n"
+      "  String name;\n"
+      "  A(this.name);\n"
+      "}\n"
+      "class B extends A {\n"
+      "  B(name) : super(name);\n"
+      "}\n"
+      "class C extends B {\n"
+      "  C(name) : super(name);\n"
+      "}\n"
+      "var list = [ new A('a'), new B('b'), new C('c') ];\n"
+      "main() {\n"
+      "  return (list.map((x) {\n"
+      "    return '${x.name} is A(${x is A})/ B(${x is B})/ C(${x is C})';\n"
+      "  })).toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("(a is A(true)/ B(false)/ C(false),"
+               " b is A(true)/ B(true)/ C(false),"
+               " c is A(true)/ B(true)/ C(true))",
+               SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "class C {\n"
+      "  String name;\n"
+      "  C(this.name);\n"
+      "}\n"
+      "class X extends C {\n"
+      "  X(name) : super(name);\n"
+      "}\n"
+      "class A extends X {\n"
+      "  A(name) : super(name);\n"
+      "}\n"
+      "var list;\n"
+      "main() {\n"
+      "  list.add(new X('x'));\n"
+      "  return (list.map((x) {\n"
+      "    return '${x.name} is A(${x is A})/ C(${x is C})/ X(${x is X})';\n"
+      "  })).toString();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("(a is A(true)/ C(true)/ X(true),"
+               " b is A(true)/ C(true)/ X(true),"  // still extends A...
+               " c is A(false)/ C(true)/ X(false),"
+               " x is A(false)/ C(true)/ X(true))",
+               SimpleInvokeStr(lib, "main"));
+
+  // Revive the class B and make sure all allocated instances take
+  // their place in the inheritance hierarchy.
+  const char* kReloadScript2 =
+      "class X {\n"
+      "  String name;\n"
+      "  X(this.name);\n"
+      "}\n"
+      "class A extends X{\n"
+      "  A(name) : super(name);\n"
+      "}\n"
+      "class B extends X {\n"
+      "  B(name) : super(name);\n"
+      "}\n"
+      "class C extends A {\n"
+      "  C(name) : super(name);\n"
+      "}\n"
+      "var list;\n"
+      "main() {\n"
+      "  return (list.map((x) {\n"
+      "    return '${x.name} is '\n"
+      "           'A(${x is A})/ B(${x is B})/ C(${x is C})/ X(${x is X})';\n"
+      "  })).toString();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript2);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("(a is A(true)/ B(false)/ C(false)/ X(true),"
+               " b is A(false)/ B(true)/ C(false)/ X(true),"
+               " c is A(true)/ B(false)/ C(true)/ X(true),"
+               " x is A(false)/ B(false)/ C(false)/ X(true))",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_LiveStack) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "helper() => 7;\n"
+      "alpha() { var x = helper(); reloadTest(); return x + helper(); }\n"
+      "foo() => alpha();\n"
+      "bar() => foo();\n"
+      "main() {\n"
+      "  return bar();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "helper() => 100;\n"
+      "alpha() => 5 + helper();\n"
+      "foo() => alpha();\n"
+      "bar() => foo();\n"
+      "main() {\n"
+      "  return bar();\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ(107, SimpleInvoke(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(105, SimpleInvoke(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_LibraryLookup) {
+  const char* kScript =
+      "main() {\n"
+      "  return importedFunc();\n"
+      "}\n";
+
+  Dart_Handle result;
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_ERROR(SimpleInvokeError(lib, "main"), "importedFunc");
+
+  // Fail to find 'importable_test_lib' in the isolate.
+  result = Dart_LookupLibrary(NewString("importable_test_lib"));
+  EXPECT(Dart_IsError(result));
+
+  const char* kReloadScript =
+      "import 'importable_test_lib';\n"
+      "main() {\n"
+      "  return importedFunc();\n"
+      "}\n";
+
+  // Reload and add 'importable_test_lib' to isolate.
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("a", SimpleInvokeStr(lib, "main"));
+
+  // Find 'importable_test_lib' in the isolate.
+  result = Dart_LookupLibrary(NewString("importable_test_lib"));
+  EXPECT(Dart_IsLibrary(result));
+
+  // Reload and remove 'dart:math' from isolate.
+  lib = TestCase::ReloadTestScript(kScript);
+  EXPECT_VALID(lib);
+
+  // Fail to find 'importable_test_lib' in the isolate.
+  result = Dart_LookupLibrary(NewString("importable_test_lib"));
+  EXPECT(Dart_IsError(result));
+}
+
+
+TEST_CASE(IsolateReload_LibraryHide) {
+  // Import 'importable_test_lib' with importedFunc hidden. Will result in an
+  // error.
+  const char* kScript =
+      "import 'importable_test_lib' hide importedFunc;\n"
+      "main() {\n"
+      "  return importedFunc();\n"
+      "}\n";
+
+  // Dart_Handle result;
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_ERROR(SimpleInvokeError(lib, "main"), "importedFunc");
+
+  // Import 'importable_test_lib'.
+  const char* kReloadScript =
+      "import 'importable_test_lib';\n"
+      "main() {\n"
+      "  return importedFunc();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("a", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_LibraryShow) {
+  // Import 'importable_test_lib' with importedIntFunc visible. Will result in
+  // an error when 'main' is invoked.
+  const char* kScript =
+      "import 'importable_test_lib' show importedIntFunc;\n"
+      "main() {\n"
+      "  return importedFunc();\n"
+      "}\n"
+      "mainInt() {\n"
+      "  return importedIntFunc();\n"
+      "}\n";
+
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  // Works.
+  EXPECT_EQ(4, SimpleInvoke(lib, "mainInt"));
+  // Results in an error.
+  EXPECT_ERROR(SimpleInvokeError(lib, "main"), "importedFunc");
+
+  // Import 'importable_test_lib' with importedFunc visible. Will result in
+  // an error when 'mainInt' is invoked.
+  const char* kReloadScript =
+      "import 'importable_test_lib' show importedFunc;\n"
+      "main() {\n"
+      "  return importedFunc();\n"
+      "}\n"
+      "mainInt() {\n"
+      "  return importedIntFunc();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  // Works.
+  EXPECT_STREQ("a", SimpleInvokeStr(lib, "main"));
+  // Results in an error.
+  EXPECT_ERROR(SimpleInvokeError(lib, "mainInt"), "importedIntFunc");
+}
+
+
+// Verifies that we clear the ICs for the functions live on the stack in a way
+// that is compatible with the fast path smi stubs.
+TEST_CASE(IsolateReload_SmiFastPathStubs) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "import 'importable_test_lib' show importedIntFunc;\n"
+      "main() {\n"
+      "  var x = importedIntFunc();\n"
+      "  var y = importedIntFunc();\n"
+      "  reloadTest();\n"
+      "  return x + y;\n"
+      "}\n";
+
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  // Identity reload.
+  TestCase::SetReloadTestScript(kScript);
+
+  EXPECT_EQ(8, SimpleInvoke(lib, "main"));
+}
+
+
+// Verifies that we assign the correct patch classes for imported
+// mixins when we reload.
+TEST_CASE(IsolateReload_ImportedMixinFunction) {
+  const char* kScript =
+      "import 'importable_test_lib' show ImportedMixin;\n"
+      "class A extends Object with ImportedMixin {\n"
+      "}"
+      "var func = new A().mixinFunc;\n"
+      "main() {\n"
+      "  return func();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("mixin", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "import 'importable_test_lib' show ImportedMixin;\n"
+      "class A extends Object with ImportedMixin {\n"
+      "}"
+      "var func;\n"
+      "main() {\n"
+      "  return func();\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("mixin", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_TopLevelParseError) {
+  const char* kScript =
+      "main() {\n"
+      "  return 4;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  const char* kReloadScript =
+      "kjsadkfjaksldfjklsadf;\n"
+      "main() {\n"
+      "  return 4;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(lib, "unexpected token");
+}
+
+
+TEST_CASE(IsolateReload_PendingUnqualifiedCall_StaticToInstance) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  static foo() => 'static';\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  return new C().test();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  foo() => 'instance';\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  return new C().test();\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ("instance", SimpleInvokeStr(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ("instance", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_PendingUnqualifiedCall_InstanceToStatic) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  foo() => 'instance';\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  return new C().test();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  static foo() => 'static';\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  return new C().test();\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ("static", SimpleInvokeStr(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ("static", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_PendingConstructorCall_AbstractToConcrete) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "abstract class Foo {}\n"
+      "class C {\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return new Foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    new C().test();\n"
+      "    return 'okay';\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class Foo {}\n"
+      "class C {\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return new Foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    new C().test();\n"
+      "    return 'okay';\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ("okay", SimpleInvokeStr(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ("okay", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_PendingConstructorCall_ConcreteToAbstract) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class Foo {}\n"
+      "class C {\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return new Foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    new C().test();\n"
+      "    return 'okay';\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "abstract class Foo {}\n"
+      "class C {\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return new Foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    new C().test();\n"
+      "    return 'okay';\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ("exception", SimpleInvokeStr(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ("exception", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_PendingStaticCall_DefinedToNSM) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  static foo() => 'static'\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return C.foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    return new C().test();\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return C.foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    return new C().test();\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ("exception", SimpleInvokeStr(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ("exception", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_PendingStaticCall_NSMToDefined) {
+  const char* kScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return C.foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    return new C().test();\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  const char* kReloadScript =
+      "import 'isolate_reload_test_helper';\n"
+      "class C {\n"
+      "  static foo() => 'static'\n"
+      "  test() {\n"
+      "    reloadTest();\n"
+      "    return C.foo();\n"
+      "  }\n"
+      "}\n"
+      "main() {\n"
+      "  try {\n"
+      "    return new C().test();\n"
+      "  } catch (e) {\n"
+      "    return 'exception';\n"
+      "  }\n"
+      "}\n";
+
+  TestCase::SetReloadTestScript(kReloadScript);
+
+  EXPECT_EQ("static", SimpleInvokeStr(lib, "main"));
+
+  lib = TestCase::GetReloadErrorOrRootLibrary();
+  EXPECT_VALID(lib);
+
+  EXPECT_EQ("static", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumEquality) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  x = Fruit.Banana;\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  if (x == Fruit.Banana) {\n"
+      "    return 'yes';\n"
+      "  } else {\n"
+      "    return 'no';\n"
+      "  }\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("yes", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumIdentical) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  x = Fruit.Banana;\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  if (identical(x, Fruit.Banana)) {\n"
+      "    return 'yes';\n"
+      "  } else {\n"
+      "    return 'no';\n"
+      "  }\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("yes", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumReorderIdentical) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  x = Fruit.Banana;\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Banana,\n"
+      "  Apple,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  if (identical(x, Fruit.Banana)) {\n"
+      "    return 'yes';\n"
+      "  } else {\n"
+      "    return 'no';\n"
+      "  }\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("yes", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumAddition) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Cantalope,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  String r = '${Fruit.Apple.index}/${Fruit.Apple} ';\n"
+      "  r += '${Fruit.Cantalope.index}/${Fruit.Cantalope} ';\n"
+      "  r += '${Fruit.Banana.index}/${Fruit.Banana}';\n"
+      "  return r;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("0/Fruit.Apple 1/Fruit.Cantalope 2/Fruit.Banana",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumToNotEnum) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple\n"
+      "}\n"
+      "main() {\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "class Fruit {\n"
+      "  final int zero = 0;\n"
+      "}\n"
+      "main() {\n"
+      "}\n";
+
+  Dart_Handle result = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(result, "Enum class cannot be redefined to be a non-enum class");
+}
+
+
+TEST_CASE(IsolateReload_NotEnumToEnum) {
+  const char* kScript =
+      "class Fruit {\n"
+      "  final int zero = 0;\n"
+      "}\n"
+      "main() {\n"
+      "  return 'yes';\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("yes", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple\n"
+      "}\n"
+      "main() {\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle result = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(result, "Class cannot be redefined to be a enum class");
+}
+
+
+TEST_CASE(IsolateReload_EnumDelete) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "  Cantalope,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  // Delete 'Cantalope'.
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  String r = '${Fruit.Apple.index}/${Fruit.Apple} ';\n"
+      "  r += '${Fruit.Banana.index}/${Fruit.Banana} ';\n"
+      "  r += '${Fruit.Cantalope.index}/${Fruit.Cantalope}';\n"
+      "  return r;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("0/Fruit.Apple 1/Fruit.Banana 2/Fruit.Cantalope",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumComplex) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "  Cantalope,\n"
+      "}\n"
+      "var x;\n"
+      "var y;\n"
+      "var z;\n"
+      "main() {\n"
+      "  x = Fruit.Apple;\n"
+      "  y = Fruit.Banana;\n"
+      "  z = Fruit.Cantalope;\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  // Delete 'Cantalope'. Add 'Dragon'. Move 'Apple' and 'Banana'.
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Dragon,\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "var y;\n"
+      "var z;\n"
+      "main() {\n"
+      "  String r = '';\n"
+      "  r += '${identical(x, Fruit.Apple)}';\n"
+      "  r += ' ${identical(y, Fruit.Banana)}';\n"
+      "  r += ' ${identical(z, Fruit.Cantalope)}';\n"
+      "  r += ' ${Fruit.Dragon}';\n"
+      "  return r;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("true true true Fruit.Dragon", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumValuesArray) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Cantalope,\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  x = Fruit.Cantalope;\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  // Delete 'Cantalope'.
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Banana,\n"
+      "  Apple\n"
+      "}\n"
+      "var x;\n"
+      "bool identityCheck(Fruit f) {\n"
+      "  return identical(Fruit.values[f.index], f);\n"
+      "}\n"
+      "main() {\n"
+      "  if ((x is Fruit) && identical(x, Fruit.Cantalope)) {\n"
+      "    String r = '${identityCheck(Fruit.Apple)}';\n"
+      "    r += ' ${identityCheck(Fruit.Banana)}';\n"
+      "    r += ' ${identityCheck(Fruit.Cantalope)}';\n"
+      "    r += ' ${identityCheck(x)}';\n"
+      "    return r;\n"
+      "  }\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("true true true true",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumIdentityReload) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "  Cantalope,\n"
+      "}\n"
+      "var x;\n"
+      "var y;\n"
+      "var z;\n"
+      "var w;\n"
+      "main() {\n"
+      "  x = { Fruit.Apple: Fruit.Apple.index,\n"
+      "        Fruit.Banana: Fruit.Banana.index,\n"
+      "        Fruit.Cantalope: Fruit.Cantalope.index};\n"
+      "  y = Fruit.Apple;\n"
+      "  z = Fruit.Banana;\n"
+      "  w = Fruit.Cantalope;\n"
+      "  return Fruit.Apple.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "  Cantalope,\n"
+      "}\n"
+      "var x;\n"
+      "var y;\n"
+      "var z;\n"
+      "var w;\n"
+      "bool identityCheck(Fruit f, int index) {\n"
+      "  return identical(Fruit.values[index], f);\n"
+      "}\n"
+      "main() {\n"
+      "  String r = '';\n"
+      "  x.forEach((key, value) {\n"
+      "    r += '${identityCheck(key, value)} ';\n"
+      "  });\n"
+      "  r += '${x[Fruit.Apple] == Fruit.Apple.index} ';\n"
+      "  r += '${x[Fruit.Banana] == Fruit.Banana.index} ';\n"
+      "  r += '${x[Fruit.Cantalope] == Fruit.Cantalope.index} ';\n"
+      "  r += '${identical(y, Fruit.values[x[Fruit.Apple]])} ';\n"
+      "  r += '${identical(z, Fruit.values[x[Fruit.Banana]])} ';\n"
+      "  r += '${identical(w, Fruit.values[x[Fruit.Cantalope]])} ';\n"
+      "  return r;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("true true true true true true true true true ",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_ConstantIdentical) {
+  const char* kScript =
+      "class Fruit {\n"
+      "  final String name;\n"
+      "  const Fruit(this.name);\n"
+      "  String toString() => name;\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  x = const Fruit('Pear');\n"
+      "  return x.toString();\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Pear", SimpleInvokeStr(lib, "main"));
+
+  const char* kReloadScript =
+      "class Fruit {\n"
+      "  final String name;\n"
+      "  const Fruit(this.name);\n"
+      "  String toString() => name;\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  if (identical(x, const Fruit('Pear'))) {\n"
+      "    return 'yes';\n"
+      "  } else {\n"
+      "    return 'no';\n"
+      "  }\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("yes", SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_EnumValuesToString) {
+  const char* kScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Banana,\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  String r = '';\n"
+      "  r += Fruit.Apple.toString();\n"
+      "  r += ' ';\n"
+      "  r += Fruit.Banana.toString();\n"
+      "  return r;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple Fruit.Banana", SimpleInvokeStr(lib, "main"));
+
+  // Insert 'Cantalope'.
+
+  const char* kReloadScript =
+      "enum Fruit {\n"
+      "  Apple,\n"
+      "  Cantalope,\n"
+      "  Banana\n"
+      "}\n"
+      "var x;\n"
+      "main() {\n"
+      "  String r = '';\n"
+      "  r += Fruit.Apple.toString();\n"
+      "  r += ' ';\n"
+      "  r += Fruit.Cantalope.toString();\n"
+      "  r += ' ';\n"
+      "  r += Fruit.Banana.toString();\n"
+      "  return r;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+
+  EXPECT_STREQ("Fruit.Apple Fruit.Cantalope Fruit.Banana",
+               SimpleInvokeStr(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_DirectSubclasses_Success) {
+  Object& new_subclass = Object::Handle();
+  String& name = String::Handle();
+
+  // Lookup the Iterator class by name from the dart core library.
+  ObjectStore* object_store = Isolate::Current()->object_store();
+  const Library& core_lib = Library::Handle(object_store->core_library());
+  name = String::New("Iterator");
+  const Class& iterator_cls = Class::Handle(core_lib.LookupClass(name));
+
+  // Keep track of how many subclasses an Iterator has.
+  const GrowableObjectArray& subclasses =
+      GrowableObjectArray::Handle(iterator_cls.direct_subclasses());
+  intptr_t saved_subclass_count = subclasses.Length();
+
+  const char* kScript =
+      "class AIterator extends Iterator {\n"
+      "}\n"
+      "main() {\n"
+      "  return 1;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(1, SimpleInvoke(lib, "main"));
+
+  // Iterator has one non-core subclass.
+  EXPECT_EQ(saved_subclass_count + 1, subclasses.Length());
+
+  // The new subclass is named AIterator.
+  new_subclass = subclasses.At(subclasses.Length() - 1);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("AIterator", name.ToCString());
+
+  const char* kReloadScript =
+      "class AIterator {\n"
+      "}\n"
+      "class BIterator extends Iterator {\n"
+      "}\n"
+      "main() {\n"
+      "  return 2;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(2, SimpleInvoke(lib, "main"));
+
+  // Iterator still has only one non-core subclass (AIterator is gone).
+  EXPECT_EQ(saved_subclass_count + 1, subclasses.Length());
+
+  // The new subclass is named BIterator.
+  new_subclass = subclasses.At(subclasses.Length() - 1);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("BIterator", name.ToCString());
+}
+
+
+TEST_CASE(IsolateReload_DirectSubclasses_GhostSubclass) {
+  Object& new_subclass = Object::Handle();
+  String& name = String::Handle();
+
+  // Lookup the Iterator class by name from the dart core library.
+  ObjectStore* object_store = Isolate::Current()->object_store();
+  const Library& core_lib = Library::Handle(object_store->core_library());
+  name = String::New("Iterator");
+  const Class& iterator_cls = Class::Handle(core_lib.LookupClass(name));
+
+  // Keep track of how many subclasses an Iterator has.
+  const GrowableObjectArray& subclasses =
+      GrowableObjectArray::Handle(iterator_cls.direct_subclasses());
+  intptr_t saved_subclass_count = subclasses.Length();
+
+  const char* kScript =
+      "class AIterator extends Iterator {\n"
+      "}\n"
+      "main() {\n"
+      "  return 1;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(1, SimpleInvoke(lib, "main"));
+
+  // Iterator has one new subclass.
+  EXPECT_EQ(saved_subclass_count + 1, subclasses.Length());
+
+  // The new subclass is named AIterator.
+  new_subclass = subclasses.At(subclasses.Length() - 1);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("AIterator", name.ToCString());
+
+  const char* kReloadScript =
+      "class BIterator extends Iterator {\n"
+      "}\n"
+      "main() {\n"
+      "  return 2;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(2, SimpleInvoke(lib, "main"));
+
+  // Iterator has two non-core subclasses.
+  EXPECT_EQ(saved_subclass_count + 2, subclasses.Length());
+
+  // The non-core subclasses are AIterator and BIterator.
+  new_subclass = subclasses.At(subclasses.Length() - 2);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("AIterator", name.ToCString());
+
+  new_subclass = subclasses.At(subclasses.Length() - 1);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("BIterator", name.ToCString());
+}
+
+
+// Make sure that we restore the direct subclass info when we revert.
+TEST_CASE(IsolateReload_DirectSubclasses_Failure) {
+  Object& new_subclass = Object::Handle();
+  String& name = String::Handle();
+
+  // Lookup the Iterator class by name from the dart core library.
+  ObjectStore* object_store = Isolate::Current()->object_store();
+  const Library& core_lib = Library::Handle(object_store->core_library());
+  name = String::New("Iterator");
+  const Class& iterator_cls = Class::Handle(core_lib.LookupClass(name));
+
+  // Keep track of how many subclasses an Iterator has.
+  const GrowableObjectArray& subclasses =
+      GrowableObjectArray::Handle(iterator_cls.direct_subclasses());
+  intptr_t saved_subclass_count = subclasses.Length();
+
+  const char* kScript =
+      "class AIterator extends Iterator {\n"
+      "}\n"
+      "class Foo {\n"
+      "  final a;\n"
+      "  Foo(this.a);\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo(5);\n"  // Force Foo to be finalized.
+      "  return 1;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(1, SimpleInvoke(lib, "main"));
+
+  // Iterator has one non-core subclass...
+  EXPECT_EQ(saved_subclass_count + 1, subclasses.Length());
+
+  // ... and the non-core subclass is named AIterator.
+  new_subclass = subclasses.At(subclasses.Length() - 1);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("AIterator", name.ToCString());
+
+  // Attempt to reload with a bogus script.
+  const char* kReloadScript =
+      "class BIterator extends Iterator {\n"
+      "}\n"
+      "class Foo {\n"
+      "  final a kjsdf ksjdf ;\n"  // When we refinalize, we get an error.
+      "  Foo(this.a);\n"
+      "}\n"
+      "main() {\n"
+      "  new Foo(5);\n"
+      "  return 2;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_ERROR(lib, "unexpected token");
+
+  // If we don't clean up the subclasses, we would find BIterator in
+  // the list of subclasses, which would be bad.  Make sure that
+  // Iterator still has only one non-core subclass...
+  EXPECT_EQ(saved_subclass_count + 1, subclasses.Length());
+
+  // ...and the non-core subclass is still named AIterator.
+  new_subclass = subclasses.At(subclasses.Length() - 1);
+  name = Class::Cast(new_subclass).Name();
+  EXPECT_STREQ("AIterator", name.ToCString());
+}
+
+#endif  // !PRODUCT
+
+}  // namespace dart