How to detect 'shinytest' is running a Shiny app?

I've found a bug in 'shinytest' with 'rhandsontable' when using 'hot_validate_numeric'.

In short, this code causes a problem with 'shinytest':

  output[["hot2"]] <- renderRHandsontable({
    rhandsontable(head(iris)) %>%
      hot_validate_numeric(col = 1, min = 0, max = 100) # <-- problem
  })

I want to test my app with 'shinytest', but I don't want to remove hot_validate_numeric(col = 1, min = 0, max = 100). So is there a way to detect that the app is powered by 'shinytest', in order to do something like:

if(shinytestIsRunning){
  output[["hot2"]] <- renderRHandsontable({
    rhandsontable(head(iris))
  })
}else{
  output[["hot2"]] <- renderRHandsontable({
    rhandsontable(head(iris)) %>%
      hot_validate_numeric(col = 1, min = 0, max = 100)
  })
}

I think I have a way.

Run 'shinytest' as follows:

library(shinytest)
app <- ShinyDriver$new(".", loadTimeout = 1e+05,
                       shinyOptions = list(test.mode = TRUE))

Then getOption("shiny.testmode") is TRUE when 'shinytest' is running the app.