Run field initializers for new instance fields after a reload

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"
@@ skipping 3111 matching lines @@
       "const value = const Duration(seconds: 2);\n"
       "main() {\n"
       "  return 'value=${value}';\n"
       "}\n";
 
   lib = TestCase::ReloadTestScript(kReloadScript);
   EXPECT_VALID(lib);
   EXPECT_STREQ("value=0:00:02.000000", SimpleInvokeStr(lib, "main"));
 }
 
+
+TEST_CASE(IsolateReload_RunNewFieldInitializers) {
+    const char* kScript =
+      "class Foo {\n"
+      "  int x = 4;\n"
+      "}\n"
+      "Foo value;\n"
+      "main() {\n"
+      "  value = new Foo();\n"
+      "  return value.x;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  // Add the field y.
+  const char* kReloadScript =
+      "class Foo {\n"
+      "  int x = 4;\n"
+      "  int y = 7;\n"
+      "}\n"
+      "Foo value;\n"
+      "main() {\n"
+      "  return value.y;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+  // Verify that we ran field initializers on existing instances.
+  EXPECT_EQ(7, SimpleInvoke(lib, "main"));
+}
+
+
+TEST_CASE(IsolateReload_RunNewFieldInitializersReferenceStaticField) {
+    const char* kScript =
+      "int myInitialValue = 8 * 7;\n"
+      "class Foo {\n"
+      "  int x = 4;\n"
+      "}\n"
+      "Foo value;\n"
+      "main() {\n"
+      "  value = new Foo();\n"
+      "  return value.x;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  // Add the field y.
+  const char* kReloadScript =
+      "int myInitialValue = 8 * 7;\n"
+      "class Foo {\n"
+      "  int x = 4;\n"
+      "  int y = myInitialValue;\n"
+      "}\n"
+      "Foo value;\n"
+      "main() {\n"
+      "  return value.y;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+  // Verify that we ran field initializers on existing instances.
+  EXPECT_EQ(56, SimpleInvoke(lib, "main"));
+}
+
+
+// The following test is expected to fail because of how we run the initializing
+// expression during reload compared to how it actually runs when the
+// constructor is invoked.

[rmacnak, 2016/11/09 00:36:32]

I don't see why this should fail. Static field access doesn't depend on an
instance context.

[Cutch, 2016/11/09 23:20:58]

Fails because of an ordering bug in my CL. Works now.

+TEST_CASE(IsolateReload_RunNewFieldInitializersMutateStaticField) {
+    const char* kScript =
+      "int myInitialValue = 8 * 7;\n"
+      "class Foo {\n"
+      "  int x = 4;\n"
+      "}\n"
+      "Foo value;\n"
+      "Foo value1;\n"
+      "main() {\n"
+      "  value = new Foo();\n"
+      "  value1 = new Foo();\n"
+      "  return value.x;\n"
+      "}\n";
+
+  Dart_Handle lib = TestCase::LoadTestScript(kScript, NULL);
+  EXPECT_VALID(lib);
+  EXPECT_EQ(4, SimpleInvoke(lib, "main"));
+
+  // Add the field y.
+  const char* kReloadScript =
+      "int myInitialValue = 8 * 7;\n"
+      "class Foo {\n"
+      "  int x = 4;\n"
+      "  int y = myInitialValue++;\n"
+      "}\n"
+      "Foo value;\n"
+      "Foo value1;\n"
+      "main() {\n"
+      "  new Foo();"
+      "  return myInitialValue;\n"
+      "}\n";
+
+  lib = TestCase::ReloadTestScript(kReloadScript);
+  EXPECT_VALID(lib);
+  // Verify that we ran field initializers on existing instances and that
+  // they affected the value of the field myInitialValue.
+  EXPECT_EQ(59, SimpleInvoke(lib, "main"));
+}

[rmacnak, 2016/11/09 00:36:32]

Add a test where the new initializer throws.

Add a test where the new field is added to a superclass, so the correct scope of
the initializer is not the receiver class. Something like

class Super {
   static foo = "right";
   var newField = foo;
}
class Sub extends Super {
   static foo = "wrong";
}
new Sub()

[Cutch, 2016/11/09 23:20:58]

Done.
Done.

 #endif  // !PRODUCT
 
 }  // namespace dart