In the Global Options of R Studio, under the Code Panel and Diagnostics Tab, there's an option that reads "Enable diagnostics within R function calls."
I had assumed that this option would trigger diagnostic warnings any time one made a mistake within a function call. For example, if I accidentally omit a comma between arguments, I get a diagnostic warning:
c(x, rep(y each = 3))
However, this warning appears in this instance whether I have the option mentioned above on or off.
When you Google this option, you get a lot of hits from people also wondering what this option does. See here. You also get a lot of hits describing this option with this exact text:
Controls whether diagnostics are performed within function calls, e.g. dplyr::select(mtcars, mpg, cyl). Toggle this if your code makes heavy use of non-standard evaluation, and RStudio is unable to produce correct diagnostics for you.
See here as one example.
I've tried reading Hadley Wickham's article on what non-standard evaluation is, and I tried "breaking" the functions he shows in that article to see if I could come up with an example of this option triggering a diagnostic warning that wouldn't already come up, and I was unsuccessful.
Can someone show an example of a mistake that trigger this specific option to trigger, i.e. the warning comes up only if this option is checked and not if it isn't?