Replace [TreatNullAs=functionName] with [StrictTypeChecking]

Source/bindings/templates/interface.cpp

 {% extends 'interface_base.cpp' %}
 
 
 {##############################################################################}
 {% macro attribute_configuration(attribute) %}
 {% set getter_callback =
        '%sV8Internal::%sAttributeGetterCallback' %
             (cpp_class, attribute.name)
        if not attribute.constructor_type else
        '{0}V8Internal::{0}ConstructorGetter'.format(interface_name) %}
@@ skipping 124 matching lines @@
 
 
 {##############################################################################}
 {% block indexed_property_setter %}
 {% if indexed_property_setter and not indexed_property_setter.is_custom %}
 {% set setter = indexed_property_setter %}
 static void indexedPropertySetter(uint32_t index, v8::Local<v8::Value> jsValue, const v8::PropertyCallbackInfo<v8::Value>& info)
 {
     {{cpp_class}}* collection = {{v8_class}}::toNative(info.Holder());
     {{setter.v8_value_to_local_cpp_value}};
+    {% if setter.has_strict_type_checking %}
+    {# Type checking for interface types (if interface not implemented, throw
+       TypeError), per http://www.w3.org/TR/WebIDL/#es-interface #}
+    if (!isUndefinedOrNull(jsValue) && !V8{{setter.idl_type}}::hasInstance(jsValue, info.GetIsolate())) {
+        exceptionState.throwTypeError("The provided value is not of type '{{setter.idl_type}}'.");
+        exceptionState.throwIfNeeded();
+        return;
+    }
+    {% endif %}
     {% set setter_name = setter.name or 'anonymousIndexedSetter' %}
     bool result = collection->{{setter_name}}(index, propertyValue);
     if (!result)
         return;
     v8SetReturnValue(info, jsValue);
 }
 
 {% endif %}
 {% endblock %}
 
@@ skipping 952 matching lines @@
     fromInternalPointer(object)->deref();
 }
 
 template<>
 v8::Handle<v8::Value> toV8NoInline({{cpp_class}}* impl, v8::Handle<v8::Object> creationContext, v8::Isolate* isolate)
 {
     return toV8(impl, creationContext, isolate);
 }
 
 {% endblock %}