How to test ToolTip in BUnit

Radzen.Blazor Components
1

I tried to validate the behavior of a tooltip (using ToolTopService) in bunit.
I failed because I do not now how to correctly trigger the mouse enter event to the element.

The component is configured like this:

<RadzenIcon
  MouseEnter="args => this.OnShowTooltip(args, new TooltipOptions { Delay = 300, Duration = 5000 }, myToolTipText)"
  MouseLeave="this.OnHideTooltip"
  Icon="announcement" IconStyle="IconStyle.Warning"/>

The ToolTipService is integrated like this:

private void OnShowTooltip(ElementReference elementReference, TooltipOptions options, string text)
{
    this.TooltipService.Open(elementReference, text, options);
}

private void OnHideTooltip()
{
    this.TooltipService.Close();
}

This is working as expected at runtime. But, I fail to create a BUnit test.
When I try to trigger the event I get an exception information that no event is available.

var icon = userCell.Descendants<HtmlElement>().Single(x => x.ClassList.Contains("rzi-warning"));
icon.TriggerEvent("MouseEnter", EventArgs.Empty);

Bunit.MissingEventHandlerException: The element does not have an event handler for the event 'MouseEnter', nor any other events.

Has anybody already successfully tested the ToolTipService behavior with BUnit?

2

As far as I can see there are extension methods directly for desired event trigger:

3

This does internally the same. Using icon.MouseOver(); I get the same exception.

4

I just checked how Bunit works and I’m afraid that it can’t be used in this case. It expects @onmouseenter Blazor event to be attached however this is not the case with RadzenTooltip which relies on attached by RadzenComponent events using plain JavaScript: