I find the
runApp('shinydir',display.mode = "showcase") quite useful for identifying which server sections get executed as the shiny app progresses.
But one annoying aspect is that the code window (on the right side) cannot be scrolled down to as much as the shiny app (on the left side) can scroll down. Perhaps the code window has got a hard stop. Even when the remaining shiny app screen can be scrolled down the code window remains stuck in a very small section. Due to this limitation we keep missing the code section that is executing and have to repeatedly go up and down to check the code section that is highlighted as yellow.
We can either solve this by allowing an infinite scroll of code window (independent of the app window) or better still an auto scroll to the yellow highlighted section.