Throw JavaScript error instead of CHECK when this in privates is invalid

extensions/renderer/module_system.cc

Index: extensions/renderer/module_system.cc
diff --git a/extensions/renderer/module_system.cc b/extensions/renderer/module_system.cc
index 1e121051e767869bf0689ae4fc8c06276289edec..028f6d6523882cfb0b9e1a0d206c77294f2b5760 100644
--- a/extensions/renderer/module_system.cc
+++ b/extensions/renderer/module_system.cc
@@ -563,8 +563,12 @@ v8::Handle<v8::String> ModuleSystem::WrapSource(v8::Handle<v8::String> source) {
 
 void ModuleSystem::Private(const v8::FunctionCallbackInfo<v8::Value>& args) {
   CHECK_EQ(1, args.Length());
-  CHECK(args[0]->IsObject());
-  CHECK(!args[0]->IsNull());
+  if (!args[0]->IsObject() || args[0]->IsNull()) {
+    GetIsolate()->ThrowException(
+        v8::String::NewFromUtf8(GetIsolate(),
+                                "Invalid invocation: this is not an object!"));
+    return;

[not at google - send to devlin, 2014/12/08 22:29:11]

Good catch, I think this is the right behaviour, though
- should throw a TypeError
- the explanation could be better and differentiate between wrong type and
undefined type. The former is something dumb, the latter is something subtle
that every JS programmer makes at some point.

So I'd say like:

if (args[0]->IsUndefined()) {
  GetIsolate()->ThrowException(v8::Exception::TypeError(
      "Method called without a receiver. Did you forget to call .bind()?");
}
... etc.

[robwu, 2014/12/08 22:39:24]

Done.

+  }
   v8::Local<v8::Object> obj = args[0].As<v8::Object>();
   v8::Local<v8::String> privates_key =
       v8::String::NewFromUtf8(GetIsolate(), "privates");