Pontifications

Put the main function in a function e.g. script_main()
Invoke debug() on that function i.e. debug(script_main). You can see this in: plot-antivirus-mentions-by-3weeks.r
Create a test script that mocks up commandArgs which is the built-in command line parsing function and debugSources the file
e.g. testRScript.R

commandArgs <- function(...) return(c("FF61", "2018", "6", "26", "FF62", "2018", "9", "5", "no"))
debugSource("plot-antivirus-mentions-by-3weeks.r")
rm(commandArgs)

and then source testRScript.R in R Studio to debug with all the great R Studio debug utilities
Important note when you run it using RScript, debug() is ignored! Here’s how to invoke it with the command line again:

Rscript ./plot-antivirus-mentions-by-3weeks.r FF61 2018 6 26 FF62 2018 9 5 yes