I am UI testing an application containing OpenLayers. Since OpenLayers is for the most part drawing an SVG, directly testing effects via DOM is not always possible.

I would like to get the map object to check if the variables within it are set correctly after clicking an element outside of the map.

For this I put the map object in window.mapInstance.

During a test, I try this:

someTest: client => {
  // regular Nightwatch testing omitted ...
  // and finally:
  client.execute(
    function () { return window },
    [],
    function (r) {
      console.log(r.value.mapInstance.getView().getZoom())
      client.end()
   }
  )
}

That throws me an error: Error while running .executeScript() protocol action: javascript error: circular reference

r.value is then set to the error object, and the whole thing fails.

What am I doing wrong?