fileSystem.retainEntry() incorrectly passed a callback?

The chrome.fileSystem.retainEntry() API does not take a callback. I am seeing chromep fail when calling this method, as Chrome appears to be doing some schema checking. I can’t find anything about where this happens, and I should be able to work around it, but it seems like chromep should be aware of this.

E.g. consider this code:

var id = chromep.fileSystem.retainEntry(entry);

At this point I would expect id to be a string. Instead it is a rejected Promise. From the console:

Promise {[[PromiseStatus]]: "rejected",
 [[PromiseValue]]: Error: Invocation of form fileSystem.retainEntry(object, function) doesn't match definition fileSystem.retainEntry(object entry)}

Is this expected? Is it something else about my environment that is interfering with things? Or perhaps a bug?

[tfoxy]

Yeah, I will add a warning to the readme tomorrow.

It would be great if this library can be a total replacement of chrome, so I will leave this open for now.

[srsudar]

Unfortunate but seems reasonable, especially with the update to the README. Your example of using chrome/chromep is nice and clean.