Make V8ValueConverter.FromV8Value behave similarly to JSON.stringify

content/renderer/v8_value_converter_impl.cc

Index: content/renderer/v8_value_converter_impl.cc
diff --git a/content/renderer/v8_value_converter_impl.cc b/content/renderer/v8_value_converter_impl.cc
index 4192ec8e4a70c46707d286ec09881e44a3da1321..bcd4dec19f7f6786af1615390a0970a035001cc1 100644
--- a/content/renderer/v8_value_converter_impl.cc
+++ b/content/renderer/v8_value_converter_impl.cc
@@ -27,18 +27,20 @@ V8ValueConverter* V8ValueConverter::create() {
 }  // namespace content
 
 V8ValueConverterImpl::V8ValueConverterImpl()
-    : undefined_allowed_(false),
+    : undefined_value_behavior_(TREAT_AS_ERROR),
       date_allowed_(false),
       regexp_allowed_(false),
       strip_null_from_objects_(false) {
 }
 
-bool V8ValueConverterImpl::GetUndefinedAllowed() const {
-  return undefined_allowed_;
+content::V8ValueConverter::UndefinedValueBehavior
+    V8ValueConverterImpl::GetUndefinedValueBehavior() const {
+  return undefined_value_behavior_;
 }
 
-void V8ValueConverterImpl::SetUndefinedAllowed(bool val) {
-  undefined_allowed_ = val;
+void V8ValueConverterImpl::SetUndefinedValueBehavior(
+    UndefinedValueBehavior val) {
+  undefined_value_behavior_ = val;
 }
 
 bool V8ValueConverterImpl::GetDateAllowed() const {
@@ -200,23 +202,43 @@ Value* V8ValueConverterImpl::FromV8ValueImpl(v8::Handle<v8::Value> val,
     return Value::CreateStringValue(std::string(*utf8, utf8.length()));
   }
 
-  if (undefined_allowed_ && val->IsUndefined())
-    return Value::CreateNullValue();
+  if (val->IsUndefined()) {
+    switch (undefined_value_behavior_) {
+      case TREAT_AS_ERROR:
+        LOG(ERROR) << "Unexpected 'undefined' v8 value encountered.";
+        return NULL;
+      case OMIT:
+        return NULL;
+      case CONVERT_TO_NULL:
+        return Value::CreateNullValue();
+    }
+    NOTREACHED();
+  }
 
-  if (date_allowed_ && val->IsDate()) {
+  if (val->IsDate()) {
+    if (!date_allowed_)
+      // JSON.stringify would convert this to a string, but {} is more
+      // consistent within this class.
+      return new DictionaryValue();
     v8::Date* date = v8::Date::Cast(*val);
     return Value::CreateDoubleValue(date->NumberValue() / 1000.0);
   }
 
-  if (regexp_allowed_ && val->IsRegExp()) {
-    return Value::CreateStringValue(
-        *v8::String::Utf8Value(val->ToString()));
+  if (val->IsRegExp()) {
+    if (!regexp_allowed_)
+      // JSON.stringify converts to {}.
+      return new DictionaryValue();
+    return Value::CreateStringValue(*v8::String::Utf8Value(val->ToString()));
   }
 
   // v8::Value doesn't have a ToArray() method for some reason.
   if (val->IsArray())
     return FromV8Array(val.As<v8::Array>(), unique_set);
 
+  if (val->IsFunction())
+    // JSON.stringify refuses to convert function(){}.
+    return NULL;
+
   if (val->IsObject()) {
     BinaryValue* binary_value = FromV8Buffer(val);
     if (binary_value) {
@@ -225,8 +247,9 @@ Value* V8ValueConverterImpl::FromV8ValueImpl(v8::Handle<v8::Value> val,
       return FromV8Object(val->ToObject(), unique_set);
     }
   }
+
   LOG(ERROR) << "Unexpected v8 value type encountered.";
-  return Value::CreateNullValue();
+  return NULL;
 }
 
 Value* V8ValueConverterImpl::FromV8Array(v8::Handle<v8::Array> val,
@@ -258,9 +281,12 @@ Value* V8ValueConverterImpl::FromV8Array(v8::Handle<v8::Array> val,
       continue;
 
     Value* child = FromV8ValueImpl(child_v8, unique_set);
-    CHECK(child);
-
-    result->Append(child);
+    if (child)
+      result->Append(child);
+    else
+      // JSON.stringify puts null in places where values don't serialize, for
+      // example undefined and functions. Emulate that behavior.
+      result->Append(Value::CreateNullValue());
   }
   return result;
 }
@@ -335,7 +361,10 @@ Value* V8ValueConverterImpl::FromV8Object(
     }
 
     scoped_ptr<Value> child(FromV8ValueImpl(child_v8, unique_set));
-    CHECK(child.get());
+    if (!child.get())
+      // JSON.stringify skips properties whose values don't serialize, for
+      // example undefined and functions. Emulate that behavior.
+      continue;
 
     // Strip null if asked (and since undefined is turned into null, undefined
     // too). The use case for supporting this is JSON-schema support,