pywebview: A call from CEF to js_api to a Python standard json library's dumps() returns a promise, but the resolved promise returns an object and not a string

Specification

• pywebview version: I don’t know where to find the version. There’s no readme in the webview folder. Folder was created on 5th of june 2019.

• platform / version: Windows 7, 32-bit

Description

A call from CEF to js_api to a Python standard json library’s dump() returns a promise, but the resolved promise returns an object and not a string

Here is the Javascript:

   function json_stringify(object, loaded_handler){
       promise1 = window.pywebview.api.json_stringify(object)
       promise1.then((value) => {
           console.log("type " + typeof(value))
           loaded_handler(value)
       })
   }
   
   setTimeout(function(){
       json_stringify({}, console.log)
   }, 3000)

The Python:

class python_interpreter_api:
    def json_stringify(self, obj):
        return str(json.dumps(obj))
        
python_interpreter_api = python_interpreter_api()

Side question: is there a way to make the js_api run Python functions synchronously? So that the javascript is halted, python is run, then javascript continues?

Note: I even added str() to json.dumps (which should be redundant) but that doesn’t work either.