text: import os
  from time import sleep
  from .util import run_test, assert_js
  import webview
  
  
  class Api:
      def test(self, params):
          return 'JS Api is working too'
  
  
  def test_start():
      api = Api()
      window = webview.create_window('Relative URL test', 'assets/test.html', js_api=api)
      run_test(webview, window, assert_func)
  
  def assert_func(window):
      sleep(1)
      html_result = window.evaluate_js('document.getElementById("heading").innerText')
      assert html_result == 'Hello there!'
  
      css_result = window.evaluate_js('window.getComputedStyle(document.body, null).getPropertyValue("background-color")')
      assert css_result == 'rgb(255, 0, 0)'
  
      js_result = window.evaluate_js('window.testResult')
      assert js_result == 80085
  
      assert_js(window, 'test', 'JS Api is working too')
  
  
  
  
  