Bug: app$layout() says it allows a collection, but it does not work

[daattali]

From the documentation:

value should be either a collection of Dash components ...

And when looking at the code, I do see that it allows a collection here

However, when I try the following code, the app runs but doesn't render the UI:

app <- Dash$new()
app$layout(list(htmlDiv("foo"), htmlDiv("bar")))
app$run_server()

There is an error in the javascript console:

Error: The children property of a component is a list of lists, instead of just a list. Check the component that has the following contents, and remove one of the levels of nesting

This may be a bug with a different part of the stack rather than the R package