Error thrown when using tooltips and dynamic data

Hi 👋

I came across an issue when using tooltips and dynamic data - it seemed to me it might be related to how the tooltips are handled in the editor, so I am opening the issue here - feel free to move it is not the right place.

Expected behavior

When having tooltips enabled and using dynamic data - by defining url by a signal value (as described here - Dynamic Data Loading section), no errors should be thrown.

Actual behavior

When enabling tooltips and using dynamic data, editor crashes with the following error

Cannot use 'in' operator to search for 'message' in Dataflow already running. Use runAsync() to chain invocations.

Steps to reproduce

1. Enable tooltips: Settings -> Tooltips checkbox
2. Use specification with dynamic data, i.e.

{
  "signals": [
    {
      "name": "testtest",
      "value": "https://jsonplaceholder.typicode.com/posts"
    }
  ],
  "data": [
    {
      "name": "baseData",
      "url": {"signal": "testtest"}
    }
  ]
}

1. Run the view (if not run automatically)
2. (An error is raised)
3. Disable the tooltips, and rerun the view
4. everything works fine

Minimal reproduction (link to editor)

Versions
Vega: 5.17.0
Vega-Lite: 4.17.0
Vega-Tooltip: 0.24.2
Editor: 0.91.2

Chrome 87.0
Firefox 83.0

[domoritz]

Could you try to reproduce the example without the editor? You can start with https://bl.ocks.org/domoritz/cd636b15fa0e187b51b73fc60b4d3014.

[domoritz]

Should fix it.