Tutorial

## Testing environments

On shinyapps.io, there’s a different environment model than on desktop R. A manifestation of this is that `eval()` statements that work fine in `{learnr}` tutorials running on the desktop don’t work on shinyapps.io.

One example of this is the `mosaicCalc::domain()` function. The statement in the code block below works fine in this tutorial run on the desktop, but doesn’t run on shinyapps.io.

    center <- 3
    width <- 4
    f <- function() {
      f2()
    }
    f2 <- function() {
      eval(quote(center))
    }
    f2()
    # domain(x = center %pm% width)
    # should give list(x=c(-1, 7))

## Tutorial